spoke tension

Quoted message said:

jim beam said:

Quoted message said:

http://www.jimbeam.com/beam/default.aspx?writes:
>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>> built with a Velocity Aerohead OC rim?
>>> JB says tension as high as the rim will bear without taking a
>>> "taco" or "potato chip" shape; however, jb says tension only as
>>> high as the manufacturer's recommendation, or the rim will crack
>>> around the spoke hole.
>>> LET THE BATTLE BEGIN!
>> That's not really what Jobst says. It's what jim beam says Jobst
>> says, which are usually two (often very) different things. I guess
>> you didn't read the book, either.
> "as high as the rim can bear" is what jobst says on this group.
> "spokes must be as tight as the rim permits" is what he says in "the
> book". [3rd edition.]
> either way, he equates increasing spoke tension with increasing
> wheel strength: "a wheel with spoke tension near the limit of rim
> strength can support large loads easily" - which is untrue,
> misleading and reveals gross misunderstanding.
I think such statements need a bit of evidence to be credible.
A wire spoked bicycle wheel can carry loads up to the point where its
spokes become slack from compression as they pass the load point on
the road. The looser the spokes the more easily this occurs and
conversely the tighter the spoke the less this occurs.

as discussed on several prior occasions, you are only considering the
spokes, not the rim. increasing spoke tension increases circumferential
rim compression. but you miss the point that as the rim's compression
rises, its load capacity decreases.

let's assume an aluminum beam has the same tensile strength as it does
compression. let's say that it yields at [pick a number] +/- 100Mpa.
in plain bending, the compressive side yields at the same time as the
tensile side - when this limit is reached. now, compress the beam
longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
but the compressive side can only support 100 - 50 = 50Mpa. so if i
bend it now, the beam will start to yield supporting only half the load
it did before.

with materials with no tensile strength like concrete, you "borrow" from
the material's [ample] compressive strength to give it pseudo tensile
strength. but with a material as strong in compression as tension, like
an aluminum bike rim, that's simply counter-productive.

in your book, you also argue that rims collapse as soon as spokes go
slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/

writing a book is one thing. understanding what to put in it is quite
another.

Quoted message said:

I have ridden many 100k miles with wheels tensioned as described
without needing to re-true them or to replace cracked rims. These
have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
ride the latter as do most of my fellow riders, ones who do not see
themselves as professional like racers..
When riding rough roads such as described in rec.bicycles.rides "Last
chance road", I and my bikie friends wonder if the light weight "with
it" crowd ever experience roads that are demanding on 36-spoke wheels.
http://tinyurl.com/2uc6tb
Dings in rims also come from insufficient inflation, a parallel to
insufficient spoke tension in supporting loads.
http://geocities.com/rayhosler/slideshow.html
Ride bike!

red herring.

This is the dilemma that many people have:

They want advise on wheels and they look for an expert's opinion.
There are two guys who respond. One says: "wheel X with Y
characteristics is ideal." The other one says: "wheel P with Q
characteristics is ideal" both offer contradictory info with some
technical and inaccessible explanations for non engineers.

so, people have to decide which poster to believe. Poster XY has
published a book that is often referred to by bicycle people who
regularly build and sell wheels, shop owners, cyclists, and other
sport aficionados. Poster XY also post pictures in which he rides
with XY wheels in dirt roads, endless hills, tours of Europe, and post
pictures of his friends riding XY wheels with the same
characteristics. Poster XY is a regular consultant for Avocet, and
gets hired to test the products. In other words, poster XY has
established a solid reputation as an expert in the field and can site
a history of expertise and product testing. Moreover, Poster XY
doesn't appear to be affiliated or to receive compensation for many of
the ideas or products that he endorses.

Now, Poster PQ post under a pseudonym. So we don't know if he has ever
published anything. The regular wheel builders in the community and
the shop owners do not seem to endorse him. We don't know if he rides
what he claims to support and has in no established credibility.

It is possible that PQs arguments are all valid. But, for those who
lack expertise to understand the explanations, credibility is
important. It is like reading a research paper with no notes and
references vs one in which all the referred information is noted,
referenced and backed.
When people disagree with poster PQ, he becomes verbally abusive in
frustration.

If poster's PQ arguments were valid, it is very unfortunate. His lack
of credibility prevents his knowledge from being disseminated. Is
there any way that poster PQ can back up his arguments by citing the
millions of wheels that he has built for friends and customers? Can ha
document the millions of miles that he has biked on his wheels? Can
he cite companies that have consulted with him and referred to his
ideas?

I think that poster PQ needs to find a way to document that his ways
have resulted in thousands of wheels being built, thousands of miles
being ridden and a following from other aficionados. If he could build
that kind of reputation, then we could have more interesting
exchanges.

I, myself have built wheels following poster XY with great success. In
fact, being a fatso and a cheapskate, I like XY's ideas, because they
are cost effective and durable and provide many miles of riding. In
fact, my bikes have inexpensive boring looking wheels a la XY. Would I
build wheels following PQ's advise? Not now, based on his current
reputation.

Just my thoughts,

Andres

whether or not you like pq's style really isn't the issue. if you don't
like it, don't read it. instead, let's look at the, er, "success" of
xy's schtick and how it depends on audience.

if the audience doesn't know all the technical facts, they rely for
judgment on the nature of presentation, appeal to alma mater authority
and whether the relatively small proportion of things they /can/ test
actually work. in the case of wheel building technique, xy's method
does indeed work. "stress relief" as a process "works" in that it
builds stable reliable wheels. but /not/ for the reasons stated! now,
how would a lay person know the difference? the limit of the typical
lay person's ability to follow the arguments presented depends on:

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

however, /if/ you're a techie and you want to follow the engineering
arguments in xy's book, you find all kinds of problems.

there are many, but they include:
1. use of the wrong stress/strain graph to explain spoke deformation.
2. use of the above to construct a "stress relief" theory - which also
takes no account of the body of fatigue research accumulated over more
than 100 years.
3. misattribution of rim cracking to anodizing based on an inappropriate
dye penetrant test.
4. misrepresenting a load calculation to be a strength calculation.
5. neglecting spoke stiffness when attempting to calculate tensiometer
deflection.

and so on.

the point is, under /technical/ scrutiny, there are problems ranging
from simple mistakes through to outright fabrication. but how will a
lay person know that and therefore be able to judge? instead, again,
they're relying on

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

and are therefore susceptible to suggestion if the "expert" wants to
extrapolate credibility.

which leads to examination of the audience. xy has chosen to promote
themselves to a carefully selected audience. the success of that is a
matter of human nature since the selected target audience has no way of
easily determining the truth.

as an example, there are regularly cases where individuals impersonate
doctors.

http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.html
http://www.local10.com/news/8830685/detail.html

these individuals talk the talk, are highly convincing, even hold down
jobs, in some cases for years. but in reality, they're frauds. they're
very clever people exploiting human gullibility and reliance on "expert"
status, but frauds nonetheless.

another example would be computer hackers. a true technical "crack" is
pretty geeky and hard to achieve. so most break-in's don't occur that
way, most system break-in's occur via "social engineering". iow,
talking a convincing talk to someone sufficiently gullible that they
give away the information necessary to gain system access. and this
happens all the time. that's why "phishing" works.

bottom line, doctor impersonators don't show up at medical symposiums
and try to present research to /real/ experts - they'll be discovered in
no time. instead, they target an audience they /know/ they can fool.
now, knowing that, and discovering that the "expert" can't do the math
and gets confused about strain aging materials when trying to formulate
"stress relief" theory, what would that tell you about the presenter and
their intended audience?

jim beam said:

Quoted message said:

jim beam said:

[email hidden] wrote:
>http://www.jimbeam.com/beam/default.aspx?writes:
>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>> built with a Velocity Aerohead OC rim?
>>>> JB says tension as high as the rim will bear without taking a
>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>> high as the manufacturer's recommendation, or the rim will crack
>>>> around the spoke hole.
>>>> LET THE BATTLE BEGIN!
>>> That's not really what Jobst says. It's what jim beam says Jobst
>>> says, which are usually two (often very) different things. I guess
>>> you didn't read the book, either.
>> "as high as the rim can bear" is what jobst says on this group.
>> "spokes must be as tight as the rim permits" is what he says in "the
>> book". [3rd edition.]
>> either way, he equates increasing spoke tension with increasing
>> wheel strength: "a wheel with spoke tension near the limit of rim
>> strength can support large loads easily" - which is untrue,
>> misleading and reveals gross misunderstanding.
> I think such statements need a bit of evidence to be credible.
> A wire spoked bicycle wheel can carry loads up to the point where its
> spokes become slack from compression as they pass the load point on
> the road. The looser the spokes the more easily this occurs and
> conversely the tighter the spoke the less this occurs.
as discussed on several prior occasions, you are only considering the
spokes, not the rim. increasing spoke tension increases circumferential
rim compression. but you miss the point that as the rim's compression
rises, its load capacity decreases.

Quoted message said:

Quoted message said:

let's assume an aluminum beam has the same tensile strength as it does
compression. let's say that it yields at [pick a number] +/- 100Mpa.
in plain bending, the compressive side yields at the same time as the
tensile side - when this limit is reached. now, compress the beam
longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
but the compressive side can only support 100 - 50 = 50Mpa. so ifi
bend it now, the beam will start to yield supporting only half the load
it did before.

Quoted message said:

Quoted message said:

with materials with no tensile strength like concrete, you "borrow" from
the material's [ample] compressive strength to give it pseudo tensile
strength. but with a material as strong in compression as tension, like
an aluminum bike rim, that's simply counter-productive.

Quoted message said:

Quoted message said:

in your book, you also argue that rims collapse as soon as spokes go
slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/

Quoted message said:

Quoted message said:

writing a book is one thing. understanding what to put in it is quite
another.

Quoted message said:

Quoted message said:

> I have ridden many 100k miles with wheels tensioned as described
> without needing to re-true them or to replace cracked rims. These
> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
> ride the latter as do most of my fellow riders, ones who do not see
> themselves as professional like racers..
> When riding rough roads such as described in rec.bicycles.rides "Last
> chance road", I and my bikie friends wonder if the light weight "with
> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>http://tinyurl.com/2uc6tb
> Dings in rims also come from insufficient inflation, a parallel to
> insufficient spoke tension in supporting loads.
>http://geocities.com/rayhosler/slideshow.html
> Ride bike!
red herring.

Quoted message said:

This is the dilemma that many people have:

Quoted message said:

They want advise on wheels and they look for an expert's opinion.
There are two guys who respond. One says: "wheel X with Y
characteristics is ideal." The other one says: "wheel P with Q
characteristics is ideal" both offer contradictory info with some
technical and inaccessible explanations for non engineers.

Quoted message said:

so, people have to decide which poster to believe. Poster XY has
published a book that is often referred to by bicycle people who
regularly build and sell wheels, shop owners, cyclists, and other
sport aficionados. Poster XY also post pictures in which he rides
with XY wheels in dirt roads, endless hills, tours of Europe, and post
pictures of his friends riding XY wheels with the same
characteristics. Poster XY is a regular consultant for Avocet, and
gets hired to test the products. In other words, poster XY has
established a solid reputation as an expert in the field and can site
a history of expertise and product testing. Moreover, Poster XY
doesn't appear to be affiliated or to receive compensation for many of
the ideas or products that he endorses.

Quoted message said:

Now, Poster PQ post under a pseudonym. So we don't know if he has ever
published anything. The regular wheel builders in the community and
the shop owners do not seem to endorse him. We don't know if he rides
what he claims to support and has in no established credibility.

Quoted message said:

It is possible that PQs arguments are all valid. But, for those who
lack expertise to understand the explanations, credibility is
important. It is like reading a research paper with no notes and
references vs one in which all the referred information is noted,
referenced and backed.
When people disagree with poster PQ, he becomes verbally abusive in
frustration.

Quoted message said:

If poster's PQ arguments were valid, it is very unfortunate. His lack
of credibility prevents his knowledge from being disseminated. Is
there any way that poster PQ can back up his arguments by citing the
millions of wheels that he has built for friends and customers? Can ha
document the millions of miles that he has biked on his wheels? Can
he cite companies that have consulted with him and referred to his
ideas?

Quoted message said:

I think that poster PQ needs to find a way to document that his ways
have resulted in thousands of wheels being built, thousands of miles
being ridden and a following from other aficionados. If he could build
that kind of reputation, then we could have more interesting
exchanges.

Quoted message said:

I, myself have built wheels following poster XY with great success. In
fact, being a fatso and a cheapskate, I like XY's ideas, because they
are cost effective and durable and provide many miles of riding. In
fact, my bikes have inexpensive boring looking wheels a la XY. Would I
build wheels following PQ's advise? Not now, based on his current
reputation.

Quoted message said:

Just my thoughts,

Quoted message said:

Andres

whether or not you like pq's style really isn't the issue. if you don't
like it, don't read it. instead, let's look at the, er, "success" of
xy's schtick and how it depends on audience.

if the audience doesn't know all the technical facts, they rely for
judgment on the nature of presentation, appeal to alma mater authority
and whether the relatively small proportion of things they /can/ test
actually work. in the case of wheel building technique, xy's method
does indeed work. "stress relief" as a process "works" in that it
builds stable reliable wheels. but /not/ for the reasons stated! now,
how would a lay person know the difference? the limit of the typical
lay person's ability to follow the arguments presented depends on:

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

however, /if/ you're a techie and you want to follow the engineering
arguments in xy's book, you find all kinds of problems.

there are many, but they include:
1. use of the wrong stress/strain graph to explain spoke deformation.
2. use of the above to construct a "stress relief" theory - which also
takes no account of the body of fatigue research accumulated over more
than 100 years.
3. misattribution of rim cracking to anodizing based on an inappropriate
dye penetrant test.
4. misrepresenting a load calculation to be a strength calculation.
5. neglecting spoke stiffness when attempting to calculate tensiometer
deflection.

and so on.

the point is, under /technical/ scrutiny, there are problems ranging
from simple mistakes through to outright fabrication. but how will a
lay person know that and therefore be able to judge? instead, again,
they're relying on

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

and are therefore susceptible to suggestion if the "expert" wants to
extrapolate credibility.

which leads to examination of the audience. xy has chosen to promote
themselves to a carefully selected audience. the success of that is a
matter of human nature since the selected target audience has no way of
easily determining the truth.

as an example, there are regularly cases where individuals impersonate
doctors.

http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlhttp://www.local10.com/news/8830685/detail.html

these individuals talk the talk, are highly convincing, even hold down
jobs, in some cases for years. but in reality, they're frauds. they're
very clever people exploiting human gullibility and reliance on "expert"
status, but frauds nonetheless.

another example would be computer hackers. a true technical "crack" is
pretty geeky and hard to achieve. so most break-in's don't occur that
way, most system break-in's occur via "social engineering". iow,
talking a convincing talk to someone sufficiently gullible that they
give away the information necessary to gain system access. and this
happens all the time. that's why "phishing" works.

bottom line, doctor impersonators don't show up at medical symposiums
and try to present research to /real/ experts - they'll be discovered in
no time. instead, they
...

read more »

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories. In fact, a couple of the techies
that support XY are often referred to in bicycling magazines work at
respectable bike shops and are also well known experts. Yet, most of
the other techies do not agree with PQ.

PQ argues that the other techies are not really techies and don't know
what they are talking about. But how are the inexperienced suppossed
to know that PQ is right? And, what is worng with the other techies?
have they been so brain washed but XY that they cannot differentiate
good from bad? Well, I would doubt it. some of the techies work on
wheels using XY's approach and PQ's approach daily. In fact, since
they are bike shop mechanics, they can actually compare the two
approaches in their daily work. They end up favoring XY's, because
they see less failure.

In my case, I have have bought bicycles that do not come up with XY's
equipment. they usually come with the latest most technologically
advanced stuff that advertisers will claim to offer. As some of the
equipment fails and I need to repair or replace it, I go with XY's
suggestions since they are cheaper, easier and more durable.

The doctor's example is a good one. I have an illness. I look for
treatment and there are lots of references to Xs treatment. In fact,
there are pictures of patients of X that have been treated by him and
seem to be better. X has published a book about his treatment, and is
often referred to by other doctors as an expert in the field. Other
doctors prescribe his treatment with success. X works at a well
established hospital, consults for a respected pharma and yet, he
doesn't seem to promote a certain brand or looking to make a buck. The
other doctors that prescribe X's treatment are also well established
and work for major clinics in the country.

Another individual "Y" of unknown qualifications claims that while X's
treatment works it is based in wrong principles, is old fashioned and
there are better treatments. Although, he cannot find support among
the other experts about his claims or the alternative treatment that
he is proposing. When other doctor's challenge Y and tell him that X
is right on, Y tells the other doctors that they don't know what he is
talking about. What shall the choice of doctors of the lay person be?

Of course, there are geniuses in the world that go against the current
and it turns out that they are right. Maybe, Y and PQ are
misunderstood geniuses.Who knows. All I can say is what I often tell a
student that doesnt' like me and wants to plot something against me. I
usually say that if he doesn't like me, but the rest of the class
does, the chances of being able to subvert my authority are slim. On
the other hand, if he can get some allies then, a larger group can
subvert my authority. I tell the same thing to my employees. If one
employee has a grievance against another one that everyone seems to
like and get along with, the chances of people listening to his or her
grievance are slim. The same applies to knowledge. If someone wants to
challenge a well established authority, then he needs some support. It
the challenger cannot get support from experts or demonstrate
objectively that the new knowledge is better, then he has a slim
chance of being listened to and a greater one of being labeled a
wacko. As I said, maybe the challenger is a misunderstood genius.
However, for a genius to waste his breath and be labeled a wacko for a
mere bike wheel is hardly worth it to me.

Andres

Quoted message said:

jim beam said:

Quoted message said:

On Jul 17, 11:33 pm, jim beam <[email hidden]> wrote:
> [email hidden] wrote:
>> http://www.jimbeam.com/beam/default.aspx?writes:
>>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>>> built with a Velocity Aerohead OC rim?
>>>>> JB says tension as high as the rim will bear without taking a
>>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>>> high as the manufacturer's recommendation, or the rim will crack
>>>>> around the spoke hole.
>>>>> LET THE BATTLE BEGIN!
>>>> That's not really what Jobst says. It's what jim beam says Jobst
>>>> says, which are usually two (often very) different things. I guess
>>>> you didn't read the book, either.
>>> "as high as the rim can bear" is what jobst says on this group.
>>> "spokes must be as tight as the rim permits" is what he says in "the
>>> book". [3rd edition.]
>>> either way, he equates increasing spoke tension with increasing
>>> wheel strength: "a wheel with spoke tension near the limit of rim
>>> strength can support large loads easily" - which is untrue,
>>> misleading and reveals gross misunderstanding.
>> I think such statements need a bit of evidence to be credible.
>> A wire spoked bicycle wheel can carry loads up to the point where its
>> spokes become slack from compression as they pass the load point on
>> the road. The looser the spokes the more easily this occurs and
>> conversely the tighter the spoke the less this occurs.
> as discussed on several prior occasions, you are only considering the
> spokes, not the rim. increasing spoke tension increases circumferential
> rim compression. but you miss the point that as the rim's compression
> rises, its load capacity decreases.
> let's assume an aluminum beam has the same tensile strength as it does
> compression. let's say that it yields at [pick a number] +/- 100Mpa.
> in plain bending, the compressive side yields at the same time as the
> tensile side - when this limit is reached. now, compress the beam
> longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
> tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
> but the compressive side can only support 100 - 50 = 50Mpa. so if i
> bend it now, the beam will start to yield supporting only half the load
> it did before.
> with materials with no tensile strength like concrete, you "borrow" from
> the material's [ample] compressive strength to give it pseudo tensile
> strength. but with a material as strong in compression as tension, like
> an aluminum bike rim, that's simply counter-productive.
> in your book, you also argue that rims collapse as soon as spokes go
> slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/
> writing a book is one thing. understanding what to put in it is quite
> another.
>> I have ridden many 100k miles with wheels tensioned as described
>> without needing to re-true them or to replace cracked rims. These
>> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
>> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
>> ride the latter as do most of my fellow riders, ones who do not see
>> themselves as professional like racers..
>> When riding rough roads such as described in rec.bicycles.rides "Last
>> chance road", I and my bikie friends wonder if the light weight "with
>> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>> http://tinyurl.com/2uc6tb
>> Dings in rims also come from insufficient inflation, a parallel to
>> insufficient spoke tension in supporting loads.
>> http://geocities.com/rayhosler/slideshow.html
>> Ride bike!
> red herring.
This is the dilemma that many people have:
They want advise on wheels and they look for an expert's opinion.
There are two guys who respond. One says: "wheel X with Y
characteristics is ideal." The other one says: "wheel P with Q
characteristics is ideal" both offer contradictory info with some
technical and inaccessible explanations for non engineers.
so, people have to decide which poster to believe. Poster XY has
published a book that is often referred to by bicycle people who
regularly build and sell wheels, shop owners, cyclists, and other
sport aficionados. Poster XY also post pictures in which he rides
with XY wheels in dirt roads, endless hills, tours of Europe, and post
pictures of his friends riding XY wheels with the same
characteristics. Poster XY is a regular consultant for Avocet, and
gets hired to test the products. In other words, poster XY has
established a solid reputation as an expert in the field and can site
a history of expertise and product testing. Moreover, Poster XY
doesn't appear to be affiliated or to receive compensation for many of
the ideas or products that he endorses.
Now, Poster PQ post under a pseudonym. So we don't know if he has ever
published anything. The regular wheel builders in the community and
the shop owners do not seem to endorse him. We don't know if he rides
what he claims to support and has in no established credibility.
It is possible that PQs arguments are all valid. But, for those who
lack expertise to understand the explanations, credibility is
important. It is like reading a research paper with no notes and
references vs one in which all the referred information is noted,
referenced and backed.
When people disagree with poster PQ, he becomes verbally abusive in
frustration.
If poster's PQ arguments were valid, it is very unfortunate. His lack
of credibility prevents his knowledge from being disseminated. Is
there any way that poster PQ can back up his arguments by citing the
millions of wheels that he has built for friends and customers? Can ha
document the millions of miles that he has biked on his wheels? Can
he cite companies that have consulted with him and referred to his
ideas?
I think that poster PQ needs to find a way to document that his ways
have resulted in thousands of wheels being built, thousands of miles
being ridden and a following from other aficionados. If he could build
that kind of reputation, then we could have more interesting
exchanges.
I, myself have built wheels following poster XY with great success. In
fact, being a fatso and a cheapskate, I like XY's ideas, because they
are cost effective and durable and provide many miles of riding. In
fact, my bikes have inexpensive boring looking wheels a la XY. Would I
build wheels following PQ's advise? Not now, based on his current
reputation.
Just my thoughts,
Andres

whether or not you like pq's style really isn't the issue. if you don't
like it, don't read it. instead, let's look at the, er, "success" of
xy's schtick and how it depends on audience.

if the audience doesn't know all the technical facts, they rely for
judgment on the nature of presentation, appeal to alma mater authority
and whether the relatively small proportion of things they /can/ test
actually work. in the case of wheel building technique, xy's method
does indeed work. "stress relief" as a process "works" in that it
builds stable reliable wheels. but /not/ for the reasons stated! now,
how would a lay person know the difference? the limit of the typical
lay person's ability to follow the arguments presented depends on:

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

however, /if/ you're a techie and you want to follow the engineering
arguments in xy's book, you find all kinds of problems.

there are many, but they include:
1. use of the wrong stress/strain graph to explain spoke deformation.
2. use of the above to construct a "stress relief" theory - which also
takes no account of the body of fatigue research accumulated over more
than 100 years.
3. misattribution of rim cracking to anodizing based on an inappropriate
dye penetrant test.
4. misrepresenting a load calculation to be a strength calculation.
5. neglecting spoke stiffness when attempting to calculate tensiometer
deflection.

and so on.

the point is, under /technical/ scrutiny, there are problems ranging
from simple mistakes through to outright fabrication. but how will a
lay person know that and therefore be able to judge? instead, again,
they're relying on

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

and are therefore susceptible to suggestion if the "expert" wants to
extrapolate credibility.

which leads to examination of the audience. xy has chosen to promote
themselves to a carefully selected audience. the success of that is a
matter of human nature since the selected target audience has no way of
easily determining the truth.

as an example, there are regularly cases where individuals impersonate
doctors.

http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlhttp://www.local10.com/news/8830685/detail.html

these individuals talk the talk, are highly convincing, even hold down
jobs, in some cases for years. but in reality, they're frauds. they're
very clever people exploiting human gullibility and reliance on "expert"
status, but frauds nonetheless.

another example would be computer hackers. a true technical "crack" is
pretty geeky and hard to achieve. so most break-in's don't occur that
way, most system break-in's occur via "social engineering". iow,
talking a convincing talk to someone sufficiently gullible that they
give away the information necessary to gain system access. and this
happens all the time. that's why "phishing" works.

bottom line, doctor impersonators don't show up at medical symposiums
and try to present research to /real/ experts - they'll be discovered in
no time. instead, they
...

read more �

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories. In fact, a couple of the techies
that support XY are often referred to in bicycling magazines work at
respectable bike shops and are also well known experts. Yet, most of
the other techies do not agree with PQ.

here's the problem with that argument - none of these "techies" spotted
any of the problems in "the book" before. if they're such reliable
experts, why not?

Quoted message said:

PQ argues that the other techies are not really techies and don't know
what they are talking about. But how are the inexperienced suppossed
to know that PQ is right? And, what is worng with the other techies?
have they been so brain washed but XY that they cannot differentiate
good from bad? Well, I would doubt it. some of the techies work on
wheels using XY's approach and PQ's approach daily. In fact, since
they are bike shop mechanics, they can actually compare the two
approaches in their daily work. They end up favoring XY's, because
they see less failure.

but the wheel build practice is good. that's been said repeatedly. and
it predates the author by at least half a century. it's the proposed
theory that's rubbish. it's based on misunderstanding and underinformed
presumption. you don't have to take any body's word for it - you can
see for yourself. check out the wheel load calcs - no accounting for
wheel strength there. check out the tensiometer math - no accounting
for spoke stiffness there. check out the stress/strain graph cited for
"stress relief" theory, then compare it with the real stress/strain
graphs at the back. real spokes show no strain aging. can't build a
theory using strain aging as a deformation mechanism if it doesn't exist.

Quoted message said:

In my case, I have have bought bicycles that do not come up with XY's
equipment. they usually come with the latest most technologically
advanced stuff that advertisers will claim to offer. As some of the
equipment fails and I need to repair or replace it, I go with XY's
suggestions since they are cheaper, easier and more durable.

The doctor's example is a good one. I have an illness. I look for
treatment and there are lots of references to Xs treatment. In fact,
there are pictures of patients of X that have been treated by him and
seem to be better. X has published a book about his treatment, and is
often referred to by other doctors as an expert in the field. Other
doctors prescribe his treatment with success. X works at a well
established hospital, consults for a respected pharma and yet, he
doesn't seem to promote a certain brand or looking to make a buck. The
other doctors that prescribe X's treatment are also well established
and work for major clinics in the country.

Another individual "Y" of unknown qualifications claims that while X's
treatment works it is based in wrong principles, is old fashioned and
there are better treatments. Although, he cannot find support among
the other experts about his claims or the alternative treatment that
he is proposing. When other doctor's challenge Y and tell him that X
is right on, Y tells the other doctors that they don't know what he is
talking about. What shall the choice of doctors of the lay person be?

Of course, there are geniuses in the world that go against the current
and it turns out that they are right. Maybe, Y and PQ are
misunderstood geniuses.Who knows. All I can say is what I often tell a
student that doesnt' like me and wants to plot something against me. I
usually say that if he doesn't like me, but the rest of the class
does, the chances of being able to subvert my authority are slim. On
the other hand, if he can get some allies then, a larger group can
subvert my authority. I tell the same thing to my employees. If one
employee has a grievance against another one that everyone seems to
like and get along with, the chances of people listening to his or her
grievance are slim. The same applies to knowledge. If someone wants to
challenge a well established authority, then he needs some support. It
the challenger cannot get support from experts or demonstrate
objectively that the new knowledge is better, then he has a slim
chance of being listened to and a greater one of being labeled a
wacko. As I said, maybe the challenger is a misunderstood genius.
However, for a genius to waste his breath and be labeled a wacko for a
mere bike wheel is hardly worth it to me.

so shut up and let you enjoy having smoke blown up your kilt in peace?
whatever floats your boat dude! but i doubt you'd feel the same if
someone started posting wrong, but pseudo "expert" information on a
subject on which /you/ happened to have detailed and specific knowledge
to the contrary. especially if they were doing it as a means of selling
you something.

jim beam said:

Quoted message said:

jim beam said:

[email hidden] wrote:
> On Jul 17, 11:33 pm, jim beam <[email hidden]> wrote:
>> [email hidden] wrote:
>>>http://www.jimbeam.com/beam/default.aspx?writes:
>>>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>>>> built with a Velocity Aerohead OC rim?
>>>>>> JB says tension as high as the rim will bear without taking a
>>>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>>>> high as the manufacturer's recommendation, or the rim will crack
>>>>>> around the spoke hole.
>>>>>> LET THE BATTLE BEGIN!
>>>>> That's not really what Jobst says. It's what jim beam says Jobst
>>>>> says, which are usually two (often very) different things. I guess
>>>>> you didn't read the book, either.
>>>> "as high as the rim can bear" is what jobst says on this group.
>>>> "spokes must be as tight as the rim permits" is what he says in "the
>>>> book". [3rd edition.]
>>>> either way, he equates increasing spoke tension with increasing
>>>> wheel strength: "a wheel with spoke tension near the limit of rim
>>>> strength can support large loads easily" - which is untrue,
>>>> misleading and reveals gross misunderstanding.
>>> I think such statements need a bit of evidence to be credible.
>>> A wire spoked bicycle wheel can carry loads up to the point where its
>>> spokes become slack from compression as they pass the load point on
>>> the road. The looser the spokes the more easily this occurs and
>>> conversely the tighter the spoke the less this occurs.
>> as discussed on several prior occasions, you are only considering the
>> spokes, not the rim. increasing spoke tension increases circumferential
>> rim compression. but you miss the point that as the rim's compression
>> rises, its load capacity decreases.
>> let's assume an aluminum beam has the same tensile strength as it does
>> compression. let's say that it yields at [pick a number] +/- 100Mpa.
>> in plain bending, the compressive side yields at the same time as the
>> tensile side - when this limit is reached. now, compress the beam
>> longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
>> tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
>> but the compressive side can only support 100 - 50 = 50Mpa. so if i
>> bend it now, the beam will start to yield supporting only half the load
>> it did before.
>> with materials with no tensile strength like concrete, you "borrow" from
>> the material's [ample] compressive strength to give it pseudo tensile
>> strength. but with a material as strong in compression as tension, like
>> an aluminum bike rim, that's simply counter-productive.
>> in your book, you also argue that rims collapse as soon as spokes go
>> slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/
>> writing a book is one thing. understanding what to put in it is quite
>> another.
>>> I have ridden many 100k miles with wheels tensioned as described
>>> without needing to re-true them or to replace cracked rims. These
>>> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
>>> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
>>> ride the latter as do most of my fellow riders, ones who do not see
>>> themselves as professional like racers..
>>> When riding rough roads such as described in rec.bicycles.rides "Last
>>> chance road", I and my bikie friends wonder if the light weight "with
>>> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>>>http://tinyurl.com/2uc6tb
>>> Dings in rims also come from insufficient inflation, a parallel to
>>> insufficient spoke tension in supporting loads.
>>>http://geocities.com/rayhosler/slideshow.html
>>> Ride bike!
>> red herring.
> This is the dilemma that many people have:
> They want advise on wheels and they look for an expert's opinion.
> There are two guys who respond. One says: "wheel X with Y
> characteristics is ideal." The other one says: "wheel P with Q
> characteristics is ideal" both offer contradictory info with some
> technical and inaccessible explanations for non engineers.
> so, people have to decide which poster to believe. Poster XY has
> published a book that is often referred to by bicycle people who
> regularly build and sell wheels, shop owners, cyclists, and other
> sport aficionados. Poster XY also post pictures in which he rides
> with XY wheels in dirt roads, endless hills, tours of Europe, and post
> pictures of his friends riding XY wheels with the same
> characteristics. Poster XY is a regular consultant for Avocet, and
> gets hired to test the products. In other words, poster XY has
> established a solid reputation as an expert in the field and can site
> a history of expertise and product testing. Moreover, Poster XY
> doesn't appear to be affiliated or to receive compensation for many of
> the ideas or products that he endorses.
> Now, Poster PQ post under a pseudonym. So we don't know if he has ever
> published anything. The regular wheel builders in the community and
> the shop owners do not seem to endorse him. We don't know if he rides
> what he claims to support and has in no established credibility.
> It is possible that PQs arguments are all valid. But, for those who
> lack expertise to understand the explanations, credibility is
> important. It is like reading a research paper with no notes and
> references vs one in which all the referred information is noted,
> referenced and backed.
> When people disagree with poster PQ, he becomes verbally abusive in
> frustration.
> If poster's PQ arguments were valid, it is very unfortunate. His lack
> of credibility prevents his knowledge from being disseminated. Is
> there any way that poster PQ can back up his arguments by citing the
> millions of wheels that he has built for friends and customers? Can ha
> document the millions of miles that he has biked on his wheels? Can
> he cite companies that have consulted with him and referred to his
> ideas?
> I think that poster PQ needs to find a way to document that his ways
> have resulted in thousands of wheels being built, thousands of miles
> being ridden and a following from other aficionados. If he could build
> that kind of reputation, then we could have more interesting
> exchanges.
> I, myself have built wheels following poster XY with great success. In
> fact, being a fatso and a cheapskate, I like XY's ideas, because they
> are cost effective and durable and provide many miles of riding. In
> fact, my bikes have inexpensive boring looking wheels a la XY. Would I
> build wheels following PQ's advise? Not now, based on his current
> reputation.
> Just my thoughts,
> Andres
whether or not you like pq's style really isn't the issue. if you don't
like it, don't read it. instead, let's look at the, er, "success" of
xy's schtick and how it depends on audience.

Quoted message said:

Quoted message said:

if the audience doesn't know all the technical facts, they rely for
judgment on the nature of presentation, appeal to alma mater authority
and whether the relatively small proportion of things they /can/ test
actually work. in the case of wheel building technique, xy's method
does indeed work. "stress relief" as a process "works" in that it
builds stable reliable wheels. but /not/ for the reasons stated! now,
how would a lay person know the difference? the limit of the typical
lay person's ability to follow the arguments presented depends on:

Quoted message said:

Quoted message said:

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

Quoted message said:

Quoted message said:

however, /if/ you're a techie and you want to follow the engineering
arguments in xy's book, you find all kinds of problems.

Quoted message said:

Quoted message said:

there are many, but they include:
1. use of the wrong stress/strain graph to explain spoke deformation.
2. use of the above to construct a "stress relief" theory - which also
takes no account of the body of fatigue research accumulated over more
than 100 years.
3. misattribution of rim cracking to anodizing based on an inappropriate
dye penetrant test.
4. misrepresenting a load calculation to be a strength calculation.
5. neglecting spoke stiffness when attempting to calculate tensiometer
deflection.

Quoted message said:

Quoted message said:

and so on.

Quoted message said:

Quoted message said:

the point is, under /technical/ scrutiny, there are problems ranging
from simple mistakes through to outright fabrication. but how will a
lay person know that and therefore be able to judge? instead, again,
they're relying on

Quoted message said:

Quoted message said:

1. presentation style
2. appeal to alma mater authority
3. success in follow wheel build instructions.

Quoted message said:

Quoted message said:

and are therefore susceptible to suggestion if the "expert" wants to
extrapolate credibility.

Quoted message said:

Quoted message said:

which leads to examination of the audience. xy has chosen to promote
themselves to a carefully selected audience. the success of that is a
matter of human nature since the selected target audience has no way of
easily determining the truth.

Quoted message said:

Quoted message said:

as an example, there are regularly cases where individuals impersonate
doctors.

Quoted message said:

Quoted message said:

http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlh...

Quoted message said:

Quoted message said:

these individuals talk the talk, are highly convincing, even hold down
jobs, in some cases for years. but in reality, they're frauds. they're
very clever people exploiting human gullibility and reliance on "expert"
status, but frauds nonetheless.

Quoted message said:

Quoted message said:

another example would be computer hackers. a true technical "crack" is
pretty geeky and hard to achieve. so most break-in's don't occur that
way, most system break-in's occur via "social engineering". iow,
talking a convincing talk to someone sufficiently gullible that they
give away the information necessary to gain system access. and this
happens all the time. that's why "phishing" works.

Quoted message said:

Quoted message said:

bottom line, doctor impersonators don't show up at medical symposiums
and try to present research to /real/ experts - they'll be discovered in
no time. instead, they
...

Quoted message said:

Quoted message said:

read more ?

Quoted message said:

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories. In fact, a couple of the techies
that support XY are often referred to in bicycling magazines work at
respectable bike shops and are also well known experts. Yet, most of
the other techies do not agree with PQ.

here's the problem with that argument - none of these "techies" spotted
any of the problems in "the book" before. if they're such reliable
experts, why not?

Quoted message said:

PQ argues that the other techies are not really techies and don't know
what they are talking about. But how are the inexperienced suppossed
to know that PQ is right? And, what is worng with the other techies?
have they been so brain washed but XY that they cannot differentiate
good from bad? Well, I would doubt it. some of the techies work on
wheels using XY's approach and PQ's approach daily. In fact, since
they are bike shop mechanics, they can actually compare the two
approaches in their daily work. They end up favoring XY's, because
they see less failure.

but the wheel build practice is good. that's been said repeatedly. and
it predates the author by at least half a century. it's the proposed
theory that's rubbish. it's based on misunderstanding and underinformed
presumption. you don't have to take any body's word for it - you can
see for yourself. check out the wheel load calcs - no accounting for
wheel strength there. check out the tensiometer math - no accounting
for spoke stiffness there. check out the stress/strain graph cited for
"stress relief" theory, then compare it with the real stress/strain
graphs at the back. real spokes show no strain aging. can't build a
theory using strain aging as a deformation mechanism if it doesn't exist.

Quoted message said:

In my case, I have have bought bicycles that do not come up with XY's
equipment. they usually come with the latest most technologically
advanced stuff that advertisers will claim to offer. As some of the
equipment fails and I need to repair or replace it, I go with XY's
suggestions since they are cheaper, easier and more durable.

Quoted message said:

The doctor's example is a good one. I have an illness. I look for
treatment and there are lots of references to Xs treatment. In fact,
there are pictures of patients of X that have been treated by him and
seem to be better. X has published a book about his treatment, and is
often referred to by other doctors as an expert in the field. Other
doctors prescribe his treatment with success. X works at a well
established hospital, consults for a respected pharma and yet, he
doesn't seem to promote a certain brand or looking to make a buck. The
other doctors that prescribe X's treatment are also well established
and work for major clinics in the country.

Quoted message said:

Another individual "Y" of unknown qualifications claims that while X's
treatment works it is based in wrong principles, is old fashioned and
there are better treatments. Although, he cannot find support among
the other experts about his claims or the alternative treatment that
he is proposing. When other doctor's challenge Y and tell him that X
is right on, Y tells the other doctors that they don't know what he is
talking about. What shall the choice of doctors of the lay person be?

Quoted message said:

Of course, there are geniuses in the world that go against the current
and it turns out that they are right. Maybe, Y and PQ are
misunderstood geniuses.Who knows. All I can say is what I often tell a
student that doesnt' like me and wants to plot something against me. I
usually say that if he doesn't like me, but the rest of the class
does, the chances of being able to subvert my authority are slim. On
the other hand, if he can get some allies then, a larger group can
subvert my authority. I tell the same thing to my employees. If one
employee has a grievance against another one that everyone seems to
like and get along with, the chances of people listening to his or her
grievance are slim. The same applies to knowledge. If someone wants to
challenge a well established authority, then he needs some support. It
the challenger cannot get support from experts or demonstrate
objectively that the new knowledge is better, then he has a slim
chance of being listened to and a greater one of being labeled a
wacko. As I said, maybe the challenger is a misunderstood genius.
However, for a genius to waste his breath and be labeled a wacko for a
mere bike wheel is hardly worth it to me.

so shut up and let you enjoy having smoke blown up your kilt in peace?
whatever floats your boat dude! but i doubt you'd feel the same if
someone started posting wrong, but pseudo "expert" information on a
subject on which /you/ happened to have detailed and specific knowledge
to the contrary. especially if they were doing it as a means of selling
you something.

Actually, the subjects that I have expertise in, I can site sources
that will back up my knowledge, evidence that something that I propose
works, colleagues who have tried using the same techniques with
positive results. If someone presented pseudo expert information, and
they often do in my field, I can pretty much articulate the reasons
for, in my field, XY's arguments are wrong. I can site my own work as
well as the work of others to show that something is nonsense. In
fact, I have to do this often. I never argue that I am right because I
am an expert and therefore I know that the other dude is a "pseudo".
If i did that I would be laughed out of my profession. I often have to
refer to other established practitioners to back up my contentions.

With regards to XY vs PQ in wheel building, there seems to be nobody
that PQ can refer to except himself who claims that XY is a pseudo
expert. IF a pseudo expert in my field presents a theory that all the
other experts buy into and I am the only one that disagrees with, then
I cease to be the expert. This is referred to as paradigm shift. Once
the accepted knowledge in a field is that XY's theories are valid,
then XY's theories represent the dominant paradigm in wheelbuilding.
For the dominant paradigm to shift, PQ will have to cite experts that
support PQ's theories.

Andres

On 2007-07-22, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories.

If you read between the lines a bit the disagreements between XY and PQ
on how to actually build a wheel are not actually so great.

XY might say for example use a lot of spoke tension, but will also be
quick to point out that if you do that on an MA3 or some modern Mavic
rims without sockets then you can expect cracked rims-- just what PQ
says. The facts are similar, it's just that XY says use a different rim
in the first place, PQ says why not use less tension. They both have
points really.

Quoted message said:

jim beam said:

Quoted message said:

On Jul 22, 3:25 pm, jim beam <[email hidden]> wrote:
> [email hidden] wrote:
>> On Jul 17, 11:33 pm, jim beam <[email hidden]> wrote:
>>> [email hidden] wrote:
>>>> http://www.jimbeam.com/beam/default.aspx?writes:
>>>>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>>>>> built with a Velocity Aerohead OC rim?
>>>>>>> JB says tension as high as the rim will bear without taking a
>>>>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>>>>> high as the manufacturer's recommendation, or the rim will crack
>>>>>>> around the spoke hole.
>>>>>>> LET THE BATTLE BEGIN!
>>>>>> That's not really what Jobst says. It's what jim beam says Jobst
>>>>>> says, which are usually two (often very) different things. I guess
>>>>>> you didn't read the book, either.
>>>>> "as high as the rim can bear" is what jobst says on this group.
>>>>> "spokes must be as tight as the rim permits" is what he says in "the
>>>>> book". [3rd edition.]
>>>>> either way, he equates increasing spoke tension with increasing
>>>>> wheel strength: "a wheel with spoke tension near the limit of rim
>>>>> strength can support large loads easily" - which is untrue,
>>>>> misleading and reveals gross misunderstanding.
>>>> I think such statements need a bit of evidence to be credible.
>>>> A wire spoked bicycle wheel can carry loads up to the point where its
>>>> spokes become slack from compression as they pass the load point on
>>>> the road. The looser the spokes the more easily this occurs and
>>>> conversely the tighter the spoke the less this occurs.
>>> as discussed on several prior occasions, you are only considering the
>>> spokes, not the rim. increasing spoke tension increases circumferential
>>> rim compression. but you miss the point that as the rim's compression
>>> rises, its load capacity decreases.
>>> let's assume an aluminum beam has the same tensile strength as it does
>>> compression. let's say that it yields at [pick a number] +/- 100Mpa.
>>> in plain bending, the compressive side yields at the same time as the
>>> tensile side - when this limit is reached. now, compress the beam
>>> longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
>>> tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
>>> but the compressive side can only support 100 - 50 = 50Mpa. so if i
>>> bend it now, the beam will start to yield supporting only half the load
>>> it did before.
>>> with materials with no tensile strength like concrete, you "borrow" from
>>> the material's [ample] compressive strength to give it pseudo tensile
>>> strength. but with a material as strong in compression as tension, like
>>> an aluminum bike rim, that's simply counter-productive.
>>> in your book, you also argue that rims collapse as soon as spokes go
>>> slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/
>>> writing a book is one thing. understanding what to put in it is quite
>>> another.
>>>> I have ridden many 100k miles with wheels tensioned as described
>>>> without needing to re-true them or to replace cracked rims. These
>>>> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
>>>> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
>>>> ride the latter as do most of my fellow riders, ones who do not see
>>>> themselves as professional like racers..
>>>> When riding rough roads such as described in rec.bicycles.rides "Last
>>>> chance road", I and my bikie friends wonder if the light weight "with
>>>> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>>>> http://tinyurl.com/2uc6tb
>>>> Dings in rims also come from insufficient inflation, a parallel to
>>>> insufficient spoke tension in supporting loads.
>>>> http://geocities.com/rayhosler/slideshow.html
>>>> Ride bike!
>>> red herring.
>> This is the dilemma that many people have:
>> They want advise on wheels and they look for an expert's opinion.
>> There are two guys who respond. One says: "wheel X with Y
>> characteristics is ideal." The other one says: "wheel P with Q
>> characteristics is ideal" both offer contradictory info with some
>> technical and inaccessible explanations for non engineers.
>> so, people have to decide which poster to believe. Poster XY has
>> published a book that is often referred to by bicycle people who
>> regularly build and sell wheels, shop owners, cyclists, and other
>> sport aficionados. Poster XY also post pictures in which he rides
>> with XY wheels in dirt roads, endless hills, tours of Europe, and post
>> pictures of his friends riding XY wheels with the same
>> characteristics. Poster XY is a regular consultant for Avocet, and
>> gets hired to test the products. In other words, poster XY has
>> established a solid reputation as an expert in the field and can site
>> a history of expertise and product testing. Moreover, Poster XY
>> doesn't appear to be affiliated or to receive compensation for many of
>> the ideas or products that he endorses.
>> Now, Poster PQ post under a pseudonym. So we don't know if he has ever
>> published anything. The regular wheel builders in the community and
>> the shop owners do not seem to endorse him. We don't know if he rides
>> what he claims to support and has in no established credibility.
>> It is possible that PQs arguments are all valid. But, for those who
>> lack expertise to understand the explanations, credibility is
>> important. It is like reading a research paper with no notes and
>> references vs one in which all the referred information is noted,
>> referenced and backed.
>> When people disagree with poster PQ, he becomes verbally abusive in
>> frustration.
>> If poster's PQ arguments were valid, it is very unfortunate. His lack
>> of credibility prevents his knowledge from being disseminated. Is
>> there any way that poster PQ can back up his arguments by citing the
>> millions of wheels that he has built for friends and customers? Can ha
>> document the millions of miles that he has biked on his wheels? Can
>> he cite companies that have consulted with him and referred to his
>> ideas?
>> I think that poster PQ needs to find a way to document that his ways
>> have resulted in thousands of wheels being built, thousands of miles
>> being ridden and a following from other aficionados. If he could build
>> that kind of reputation, then we could have more interesting
>> exchanges.
>> I, myself have built wheels following poster XY with great success. In
>> fact, being a fatso and a cheapskate, I like XY's ideas, because they
>> are cost effective and durable and provide many miles of riding. In
>> fact, my bikes have inexpensive boring looking wheels a la XY. Would I
>> build wheels following PQ's advise? Not now, based on his current
>> reputation.
>> Just my thoughts,
>> Andres
> whether or not you like pq's style really isn't the issue. if you don't
> like it, don't read it. instead, let's look at the, er, "success" of
> xy's schtick and how it depends on audience.
> if the audience doesn't know all the technical facts, they rely for
> judgment on the nature of presentation, appeal to alma mater authority
> and whether the relatively small proportion of things they /can/ test
> actually work. in the case of wheel building technique, xy's method
> does indeed work. "stress relief" as a process "works" in that it
> builds stable reliable wheels. but /not/ for the reasons stated! now,
> how would a lay person know the difference? the limit of the typical
> lay person's ability to follow the arguments presented depends on:
> 1. presentation style
> 2. appeal to alma mater authority
> 3. success in follow wheel build instructions.
> however, /if/ you're a techie and you want to follow the engineering
> arguments in xy's book, you find all kinds of problems.
> there are many, but they include:
> 1. use of the wrong stress/strain graph to explain spoke deformation.
> 2. use of the above to construct a "stress relief" theory - which also
> takes no account of the body of fatigue research accumulated over more
> than 100 years.
> 3. misattribution of rim cracking to anodizing based on an inappropriate
> dye penetrant test.
> 4. misrepresenting a load calculation to be a strength calculation.
> 5. neglecting spoke stiffness when attempting to calculate tensiometer
> deflection.
> and so on.
> the point is, under /technical/ scrutiny, there are problems ranging
> from simple mistakes through to outright fabrication. but how will a
> lay person know that and therefore be able to judge? instead, again,
> they're relying on
> 1. presentation style
> 2. appeal to alma mater authority
> 3. success in follow wheel build instructions.
> and are therefore susceptible to suggestion if the "expert" wants to
> extrapolate credibility.
> which leads to examination of the audience. xy has chosen to promote
> themselves to a carefully selected audience. the success of that is a
> matter of human nature since the selected target audience has no way of
> easily determining the truth.
> as an example, there are regularly cases where individuals impersonate
> doctors.
> http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlh...
> these individuals talk the talk, are highly convincing, even hold down
> jobs, in some cases for years. but in reality, they're frauds. they're
> very clever people exploiting human gullibility and reliance on "expert"
> status, but frauds nonetheless.
> another example would be computer hackers. a true technical "crack" is
> pretty geeky and hard to achieve. so most break-in's don't occur that
> way, most system break-in's occur via "social engineering". iow,
> talking a convincing talk to someone sufficiently gullible that they
> give away the information necessary to gain system access. and this
> happens all the time. that's why "phishing" works.
> bottom line, doctor impersonators don't show up at medical symposiums
> and try to present research to /real/ experts - they'll be discovered in
> no time. instead, they
> ...
> read more ?
Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories. In fact, a couple of the techies
that support XY are often referred to in bicycling magazines work at
respectable bike shops and are also well known experts. Yet, most of
the other techies do not agree with PQ.

here's the problem with that argument - none of these "techies" spotted
any of the problems in "the book" before. if they're such reliable
experts, why not?

Quoted message said:

PQ argues that the other techies are not really techies and don't know
what they are talking about. But how are the inexperienced suppossed
to know that PQ is right? And, what is worng with the other techies?
have they been so brain washed but XY that they cannot differentiate
good from bad? Well, I would doubt it. some of the techies work on
wheels using XY's approach and PQ's approach daily. In fact, since
they are bike shop mechanics, they can actually compare the two
approaches in their daily work. They end up favoring XY's, because
they see less failure.

but the wheel build practice is good. that's been said repeatedly. and
it predates the author by at least half a century. it's the proposed
theory that's rubbish. it's based on misunderstanding and underinformed
presumption. you don't have to take any body's word for it - you can
see for yourself. check out the wheel load calcs - no accounting for
wheel strength there. check out the tensiometer math - no accounting
for spoke stiffness there. check out the stress/strain graph cited for
"stress relief" theory, then compare it with the real stress/strain
graphs at the back. real spokes show no strain aging. can't build a
theory using strain aging as a deformation mechanism if it doesn't exist.

Quoted message said:

In my case, I have have bought bicycles that do not come up with XY's
equipment. they usually come with the latest most technologically
advanced stuff that advertisers will claim to offer. As some of the
equipment fails and I need to repair or replace it, I go with XY's
suggestions since they are cheaper, easier and more durable.
The doctor's example is a good one. I have an illness. I look for
treatment and there are lots of references to Xs treatment. In fact,
there are pictures of patients of X that have been treated by him and
seem to be better. X has published a book about his treatment, and is
often referred to by other doctors as an expert in the field. Other
doctors prescribe his treatment with success. X works at a well
established hospital, consults for a respected pharma and yet, he
doesn't seem to promote a certain brand or looking to make a buck. The
other doctors that prescribe X's treatment are also well established
and work for major clinics in the country.
Another individual "Y" of unknown qualifications claims that while X's
treatment works it is based in wrong principles, is old fashioned and
there are better treatments. Although, he cannot find support among
the other experts about his claims or the alternative treatment that
he is proposing. When other doctor's challenge Y and tell him that X
is right on, Y tells the other doctors that they don't know what he is
talking about. What shall the choice of doctors of the lay person be?
Of course, there are geniuses in the world that go against the current
and it turns out that they are right. Maybe, Y and PQ are
misunderstood geniuses.Who knows. All I can say is what I often tell a
student that doesnt' like me and wants to plot something against me. I
usually say that if he doesn't like me, but the rest of the class
does, the chances of being able to subvert my authority are slim. On
the other hand, if he can get some allies then, a larger group can
subvert my authority. I tell the same thing to my employees. If one
employee has a grievance against another one that everyone seems to
like and get along with, the chances of people listening to his or her
grievance are slim. The same applies to knowledge. If someone wants to
challenge a well established authority, then he needs some support. It
the challenger cannot get support from experts or demonstrate
objectively that the new knowledge is better, then he has a slim
chance of being listened to and a greater one of being labeled a
wacko. As I said, maybe the challenger is a misunderstood genius.
However, for a genius to waste his breath and be labeled a wacko for a
mere bike wheel is hardly worth it to me.

so shut up and let you enjoy having smoke blown up your kilt in peace?
whatever floats your boat dude! but i doubt you'd feel the same if
someone started posting wrong, but pseudo "expert" information on a
subject on which /you/ happened to have detailed and specific knowledge
to the contrary. especially if they were doing it as a means of selling
you something.

Actually, the subjects that I have expertise in, I can site sources
that will back up my knowledge, evidence that something that I propose
works, colleagues who have tried using the same techniques with
positive results. If someone presented pseudo expert information, and
they often do in my field, I can pretty much articulate the reasons
for, in my field, XY's arguments are wrong. I can site my own work as
well as the work of others to show that something is nonsense. In
fact, I have to do this often. I never argue that I am right because I
am an expert and therefore I know that the other dude is a "pseudo".
If i did that I would be laughed out of my profession. I often have to
refer to other established practitioners to back up my contentions.

With regards to XY vs PQ in wheel building, there seems to be nobody
that PQ can refer to except himself who claims that XY is a pseudo
expert. IF a pseudo expert in my field presents a theory that all the
other experts buy into and I am the only one that disagrees with, then
I cease to be the expert. This is referred to as paradigm shift. Once
the accepted knowledge in a field is that XY's theories are valid,
then XY's theories represent the dominant paradigm in wheelbuilding.

in terms of wheel assembly, they represent industry practice that
existed from /way/ back. in terms of theory, a lot of it is b.s.
"dominant paradigm" comes from relentless self-promotion to a selected
audience that has never bothered to check the math or crack open a
materials book. [references!] if these theories of "stress relief",
were presented to a symposium of materials experts, they laugh their
asses off. etc.

Quoted message said:

For the dominant paradigm to shift, PQ will have to cite experts that
support PQ's theories.

so what does the ability to successfully assemble a wheel tell you about
fatigue in non-strain aging materials? what does it tell you about
pre-stressed structure theory? what does it tell you about tensiometer
math? the point is, "credibility" in wheel assembly is /NOT/
credibility in engineering theory! that's the mistake of your argument.

Ben C said:

On 2007-07-22, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories.

If you read between the lines a bit the disagreements between XY and PQ
on how to actually build a wheel are not actually so great.

except that i'm not interested in telling people how to build wheels. i
/am/ interested in making sure people correctly understand materials
theory though, and half-baked "stress relief" theories based on
misunderstanding and presumption is simply unacceptable.

Quoted message said:

XY might say for example use a lot of spoke tension, but will also be
quick to point out that if you do that on an MA3 or some modern Mavic
rims without sockets then you can expect cracked rims-- just what PQ
says. The facts are similar, it's just that XY says use a different rim
in the first place, PQ says why not use less tension. They both have
points really.

jim beam said:

Quoted message said:

jim beam said:

[email hidden] wrote:
> On Jul 22, 3:25 pm, jim beam <[email hidden]> wrote:
>> [email hidden] wrote:
>>> On Jul 17, 11:33 pm, jim beam <[email hidden]> wrote:
>>>> [email hidden] wrote:
>>>>>http://www.jimbeam.com/beam/default.aspx?writes:
>>>>>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>>>>>> built with a Velocity Aerohead OC rim?
>>>>>>>> JB says tension as high as the rim will bear without taking a
>>>>>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>>>>>> high as the manufacturer's recommendation, or the rim will crack
>>>>>>>> around the spoke hole.
>>>>>>>> LET THE BATTLE BEGIN!
>>>>>>> That's not really what Jobst says. It's what jim beam says Jobst
>>>>>>> says, which are usually two (often very) different things. I guess
>>>>>>> you didn't read the book, either.
>>>>>> "as high as the rim can bear" is what jobst says on this group.
>>>>>> "spokes must be as tight as the rim permits" is what he says in "the
>>>>>> book". [3rd edition.]
>>>>>> either way, he equates increasing spoke tension with increasing
>>>>>> wheel strength: "a wheel with spoke tension near the limit of rim
>>>>>> strength can support large loads easily" - which is untrue,
>>>>>> misleading and reveals gross misunderstanding.
>>>>> I think such statements need a bit of evidence to be credible.
>>>>> A wire spoked bicycle wheel can carry loads up to the point where its
>>>>> spokes become slack from compression as they pass the load point on
>>>>> the road. The looser the spokes the more easily this occurs and
>>>>> conversely the tighter the spoke the less this occurs.
>>>> as discussed on several prior occasions, you are only considering the
>>>> spokes, not the rim. increasing spoke tension increases circumferential
>>>> rim compression. but you miss the point that as the rim's compression
>>>> rises, its load capacity decreases.
>>>> let's assume an aluminum beam has the same tensile strength as it does
>>>> compression. let's say that it yields at [pick a number] +/- 100Mpa.
>>>> in plain bending, the compressive side yields at the same time as the
>>>> tensile side - when this limit is reached. now, compress the beam
>>>> longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
>>>> tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
>>>> but the compressive side can only support 100 - 50 = 50Mpa. so if i
>>>> bend it now, the beam will start to yield supporting only half the load
>>>> it did before.
>>>> with materials with no tensile strength like concrete, you "borrow" from
>>>> the material's [ample] compressive strength to give it pseudo tensile
>>>> strength. but with a material as strong in compression as tension, like
>>>> an aluminum bike rim, that's simply counter-productive.
>>>> in your book, you also argue that rims collapse as soon as spokes go
>>>> slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/
>>>> writing a book is one thing. understanding what to put in it is quite
>>>> another.
>>>>> I have ridden many 100k miles with wheels tensioned as described
>>>>> without needing to re-true them or to replace cracked rims. These
>>>>> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
>>>>> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
>>>>> ride the latter as do most of my fellow riders, ones who do not see
>>>>> themselves as professional like racers..
>>>>> When riding rough roads such as described in rec.bicycles.rides "Last
>>>>> chance road", I and my bikie friends wonder if the light weight "with
>>>>> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>>>>>http://tinyurl.com/2uc6tb
>>>>> Dings in rims also come from insufficient inflation, a parallel to
>>>>> insufficient spoke tension in supporting loads.
>>>>>http://geocities.com/rayhosler/slideshow.html
>>>>> Ride bike!
>>>> red herring.
>>> This is the dilemma that many people have:
>>> They want advise on wheels and they look for an expert's opinion.
>>> There are two guys who respond. One says: "wheel X with Y
>>> characteristics is ideal." The other one says: "wheel P with Q
>>> characteristics is ideal" both offer contradictory info with some
>>> technical and inaccessible explanations for non engineers.
>>> so, people have to decide which poster to believe. Poster XY has
>>> published a book that is often referred to by bicycle people who
>>> regularly build and sell wheels, shop owners, cyclists, and other
>>> sport aficionados. Poster XY also post pictures in which he rides
>>> with XY wheels in dirt roads, endless hills, tours of Europe, and post
>>> pictures of his friends riding XY wheels with the same
>>> characteristics. Poster XY is a regular consultant for Avocet, and
>>> gets hired to test the products. In other words, poster XY has
>>> established a solid reputation as an expert in the field and can site
>>> a history of expertise and product testing. Moreover, Poster XY
>>> doesn't appear to be affiliated or to receive compensation for many of
>>> the ideas or products that he endorses.
>>> Now, Poster PQ post under a pseudonym. So we don't know if he has ever
>>> published anything. The regular wheel builders in the community and
>>> the shop owners do not seem to endorse him. We don't know if he rides
>>> what he claims to support and has in no established credibility.
>>> It is possible that PQs arguments are all valid. But, for those who
>>> lack expertise to understand the explanations, credibility is
>>> important. It is like reading a research paper with no notes and
>>> references vs one in which all the referred information is noted,
>>> referenced and backed.
>>> When people disagree with poster PQ, he becomes verbally abusive in
>>> frustration.
>>> If poster's PQ arguments were valid, it is very unfortunate. His lack
>>> of credibility prevents his knowledge from being disseminated. Is
>>> there any way that poster PQ can back up his arguments by citing the
>>> millions of wheels that he has built for friends and customers? Can ha
>>> document the millions of miles that he has biked on his wheels? Can
>>> he cite companies that have consulted with him and referred to his
>>> ideas?
>>> I think that poster PQ needs to find a way to document that his ways
>>> have resulted in thousands of wheels being built, thousands of miles
>>> being ridden and a following from other aficionados. If he could build
>>> that kind of reputation, then we could have more interesting
>>> exchanges.
>>> I, myself have built wheels following poster XY with great success. In
>>> fact, being a fatso and a cheapskate, I like XY's ideas, because they
>>> are cost effective and durable and provide many miles of riding. In
>>> fact, my bikes have inexpensive boring looking wheels a la XY. Would I
>>> build wheels following PQ's advise? Not now, based on his current
>>> reputation.
>>> Just my thoughts,
>>> Andres
>> whether or not you like pq's style really isn't the issue. if you don't
>> like it, don't read it. instead, let's look at the, er, "success" of
>> xy's schtick and how it depends on audience.
>> if the audience doesn't know all the technical facts, they rely for
>> judgment on the nature of presentation, appeal to alma mater authority
>> and whether the relatively small proportion of things they /can/ test
>> actually work. in the case of wheel building technique, xy's method
>> does indeed work. "stress relief" as a process "works" in that it
>> builds stable reliable wheels. but /not/ for the reasons stated! now,
>> how would a lay person know the difference? the limit of the typical
>> lay person's ability to follow the arguments presented depends on:
>> 1. presentation style
>> 2. appeal to alma mater authority
>> 3. success in follow wheel build instructions.
>> however, /if/ you're a techie and you want to follow the engineering
>> arguments in xy's book, you find all kinds of problems.
>> there are many, but they include:
>> 1. use of the wrong stress/strain graph to explain spoke deformation.
>> 2. use of the above to construct a "stress relief" theory - which also
>> takes no account of the body of fatigue research accumulated over more
>> than 100 years.
>> 3. misattribution of rim cracking to anodizing based on an inappropriate
>> dye penetrant test.
>> 4. misrepresenting a load calculation to be a strength calculation.
>> 5. neglecting spoke stiffness when attempting to calculate tensiometer
>> deflection.
>> and so on.
>> the point is, under /technical/ scrutiny, there are problems ranging
>> from simple mistakes through to outright fabrication. but how will a
>> lay person know that and therefore be able to judge? instead, again,
>> they're relying on
>> 1. presentation style
>> 2. appeal to alma mater authority
>> 3. success in follow wheel build instructions.
>> and are therefore susceptible to suggestion if the "expert" wants to
>> extrapolate credibility.
>> which leads to examination of the audience. xy has chosen to promote
>> themselves to a carefully selected audience. the success of that is a
>> matter of human nature since the selected target audience has no way of
>> easily determining the truth.
>> as an example, there are regularly cases where individuals impersonate
>> doctors.
>>http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlh...
>> these individuals talk the talk, are highly convincing, even hold down
>> jobs, in some cases for years. but in reality, they're frauds. they're
>> very clever people exploiting human gullibility and reliance on "expert"
>> status, but frauds nonetheless.
>> another example would be computer hackers. a true technical "crack" is
>> pretty geeky and hard to achieve. so most break-in's don't occur that
>> way, most system break-in's occur via "social engineering". iow,
>> talking a convincing talk to someone sufficiently gullible that they
>> give away the information necessary to gain system access. and this
>> happens all the time. that's why "phishing" works.
>> bottom line, doctor impersonators don't show up at medical symposiums
>> and try to present research to /real/ experts - they'll be discovered in
>> no time. instead, they
>> ...
>> read more ?
> Problem is that the other techies in the group seem to agree with XY's
> theories and not with PQs theories. In fact, a couple of the techies
> that support XY are often referred to in bicycling magazines work at
> respectable bike shops and are also well known experts. Yet, most of
> the other techies do not agree with PQ.
here's the problem with that argument - none of these "techies" spotted
any of the problems in "the book" before. if they're such reliable
experts, why not?

Quoted message said:

Quoted message said:

> PQ argues that the other techies are not really techies and don't know
> what they are talking about. But how are the inexperienced suppossed
> to know that PQ is right? And, what is worng with the other techies?
> have they been so brain washed but XY that they cannot differentiate
> good from bad? Well, I would doubt it. some of the techies work on
> wheels using XY's approach and PQ's approach daily. In fact, since
> they are bike shop mechanics, they can actually compare the two
> approaches in their daily work. They end up favoring XY's, because
> they see less failure.
but the wheel build practice is good. that's been said repeatedly. and
it predates the author by at least half a century. it's the proposed
theory that's rubbish. it's based on misunderstanding and underinformed
presumption. you don't have to take any body's word for it - you can
see for yourself. check out the wheel load calcs - no accounting for
wheel strength there. check out the tensiometer math - no accounting
for spoke stiffness there. check out the stress/strain graph cited for
"stress relief" theory, then compare it with the real stress/strain
graphs at the back. real spokes show no strain aging. can't build a
theory using strain aging as a deformation mechanism if it doesn't exist.

Quoted message said:

Quoted message said:

> In my case, I have have bought bicycles that do not come up with XY's
> equipment. they usually come with the latest most technologically
> advanced stuff that advertisers will claim to offer. As some of the
> equipment fails and I need to repair or replace it, I go with XY's
> suggestions since they are cheaper, easier and more durable.
> The doctor's example is a good one. I have an illness. I look for
> treatment and there are lots of references to Xs treatment. In fact,
> there are pictures of patients of X that have been treated by him and
> seem to be better. X has published a book about his treatment, and is
> often referred to by other doctors as an expert in the field. Other
> doctors prescribe his treatment with success. X works at a well
> established hospital, consults for a respected pharma and yet, he
> doesn't seem to promote a certain brand or looking to make a buck. The
> other doctors that prescribe X's treatment are also well established
> and work for major clinics in the country.
> Another individual "Y" of unknown qualifications claims that while X's
> treatment works it is based in wrong principles, is old fashioned and
> there are better treatments. Although, he cannot find support among
> the other experts about his claims or the alternative treatment that
> he is proposing. When other doctor's challenge Y and tell him that X
> is right on, Y tells the other doctors that they don't know what he is
> talking about. What shall the choice of doctors of the lay person be?
> Of course, there are geniuses in the world that go against the current
> and it turns out that they are right. Maybe, Y and PQ are
> misunderstood geniuses.Who knows. All I can say is what I often tell a
> student that doesnt' like me and wants to plot something against me. I
> usually say that if he doesn't like me, but the rest of the class
> does, the chances of being able to subvert my authority are slim. On
> the other hand, if he can get some allies then, a larger group can
> subvert my authority. I tell the same thing to my employees. If one
> employee has a grievance against another one that everyone seems to
> like and get along with, the chances of people listening to his or her
> grievance are slim. The same applies to knowledge. If someone wants to
> challenge a well established authority, then he needs some support. It
> the challenger cannot get support from experts or demonstrate
> objectively that the new knowledge is better, then he has a slim
> chance of being listened to and a greater one of being labeled a
> wacko. As I said, maybe the challenger is a misunderstood genius.
> However, for a genius to waste his breath and be labeled a wacko for a
> mere bike wheel is hardly worth it to me.
so shut up and let you enjoy having smoke blown up your kilt in peace?
whatever floats your boat dude! but i doubt you'd feel the same if
someone started posting wrong, but pseudo "expert" information on a
subject on which /you/ happened to have detailed and specific knowledge
to the contrary. especially if they were doing it as a means of selling
you something.

Quoted message said:

Actually, the subjects that I have expertise in, I can site sources
that will back up my knowledge, evidence that something that I propose
works, colleagues who have tried using the same techniques with
positive results. If someone presented pseudo expert information, and
they often do in my field, I can pretty much articulate the reasons
for, in my field, XY's arguments are wrong. I can site my own work as
well as the work of others to show that something is nonsense. In
fact, I have to do this often. I never argue that I am right because I
am an expert and therefore I know that the other dude is a "pseudo".
If i did that I would be laughed out of my profession. I often have to
refer to other established practitioners to back up my contentions.

Quoted message said:

With regards to XY vs PQ in wheel building, there seems to be nobody
that PQ can refer to except himself who claims that XY is a pseudo
expert. IF a pseudo expert in my field presents a theory that all the
other experts buy into and I am the only one that disagrees with, then
I cease to be the expert. This is referred to as paradigm shift. Once
the accepted knowledge in a field is that XY's theories are valid,
then XY's theories represent the dominant paradigm in wheelbuilding.

in terms of wheel assembly, they represent industry practice that
existed from /way/ back. in terms of theory, a lot of it is b.s.
"dominant paradigm" comes from relentless self-promotion to a selected
audience that has never bothered to check the math or crack open a
materials book. [references!] if these theories of "stress relief",
were presented to a symposium of materials experts, they laugh their
asses off. etc.

Quoted message said:

For the dominant paradigm to shift, PQ will have to cite experts that
support PQ's theories.

so what does the ability to successfully assemble a wheel tell you about
fatigue in non-strain aging materials? what does it tell you about
pre-stressed structure theory? what does it tell you about tensiometer
math? the point is, "credibility" in wheel assembly is /NOT/
credibility in engineering theory! that's the mistake of your argument

I have no idea, but this is not a theoretical engineering discussion
group. I know that theory and practice are related, and there are
engineers that are interested in bicycle wheels and physics forces of
bicycle riding. some are posters in this group. some may be posters or
component developers in other groups. so, are there any engineers,
physicists, mathematicians that support PQ in statying that XY's
engineering claims are nonesense? Are XY and PQ the only two
individuals with expertise in this subject. we know that XY is an
engineer. Is PQ also an engineer?

Andres

jim beam said:

Ben C said:

On 2007-07-22, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories.

Quoted message said:

If you read between the lines a bit the disagreements between XY and PQ
on how to actually build a wheel are not actually so great.

except that i'm not interested in telling people how to build wheels. i
/am/ interested in making sure people correctly understand materials
theory though,

You want to teach us material's theory? How do we know that you are
qualified to teach it? Again, an expert in a field must be able to
note his claims with credibility, citations past accomplishments, etc.
Is there anyone else in this group that knows about materials theory
that can substantiate your claims? Any engineers or physicists here
that know about materials theory that can agree that JB is talking
nonesense? Are you the only expert that has figured this out and you
are misunderstood?

Andres

jim beam said:

Ben C said:

On 2007-07-22, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

Problem is that the other techies in the group seem to agree with XY's
theories and not with PQs theories.

If you read between the lines a bit the disagreements between XY and PQ
on how to actually build a wheel are not actually so great.

except that i'm not interested in telling people how to build wheels.
i /am/ interested in making sure people correctly understand materials
theory though, and half-baked "stress relief" theories based on
misunderstanding and presumption is simply unacceptable.

Absolutely.

Quoted message said:

jim beam said:

Quoted message said:

On Jul 22, 7:22 pm, jim beam <[email hidden]> wrote:
> [email hidden] wrote:
>> On Jul 22, 3:25 pm, jim beam <[email hidden]> wrote:
>>> [email hidden] wrote:
>>>> On Jul 17, 11:33 pm, jim beam <[email hidden]> wrote:
>>>>> [email hidden] wrote:
>>>>>> http://www.jimbeam.com/beam/default.aspx?writes:
>>>>>>>>>> Could someone recommend the proper spoke tension for a rear wheel
>>>>>>>>>> built with a Velocity Aerohead OC rim?
>>>>>>>>> JB says tension as high as the rim will bear without taking a
>>>>>>>>> "taco" or "potato chip" shape; however, jb says tension only as
>>>>>>>>> high as the manufacturer's recommendation, or the rim will crack
>>>>>>>>> around the spoke hole.
>>>>>>>>> LET THE BATTLE BEGIN!
>>>>>>>> That's not really what Jobst says. It's what jim beam says Jobst
>>>>>>>> says, which are usually two (often very) different things. I guess
>>>>>>>> you didn't read the book, either.
>>>>>>> "as high as the rim can bear" is what jobst says on this group.
>>>>>>> "spokes must be as tight as the rim permits" is what he says in "the
>>>>>>> book". [3rd edition.]
>>>>>>> either way, he equates increasing spoke tension with increasing
>>>>>>> wheel strength: "a wheel with spoke tension near the limit of rim
>>>>>>> strength can support large loads easily" - which is untrue,
>>>>>>> misleading and reveals gross misunderstanding.
>>>>>> I think such statements need a bit of evidence to be credible.
>>>>>> A wire spoked bicycle wheel can carry loads up to the point where its
>>>>>> spokes become slack from compression as they pass the load point on
>>>>>> the road. The looser the spokes the more easily this occurs and
>>>>>> conversely the tighter the spoke the less this occurs.
>>>>> as discussed on several prior occasions, you are only considering the
>>>>> spokes, not the rim. increasing spoke tension increases circumferential
>>>>> rim compression. but you miss the point that as the rim's compression
>>>>> rises, its load capacity decreases.
>>>>> let's assume an aluminum beam has the same tensile strength as it does
>>>>> compression. let's say that it yields at [pick a number] +/- 100Mpa.
>>>>> in plain bending, the compressive side yields at the same time as the
>>>>> tensile side - when this limit is reached. now, compress the beam
>>>>> longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
>>>>> tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
>>>>> but the compressive side can only support 100 - 50 = 50Mpa. so if i
>>>>> bend it now, the beam will start to yield supporting only half the load
>>>>> it did before.
>>>>> with materials with no tensile strength like concrete, you "borrow" from
>>>>> the material's [ample] compressive strength to give it pseudo tensile
>>>>> strength. but with a material as strong in compression as tension, like
>>>>> an aluminum bike rim, that's simply counter-productive.
>>>>> in your book, you also argue that rims collapse as soon as spokes go
>>>>> slack go slack....http://www.flickr.com/photos/38636024@N00/417157612/
>>>>> writing a book is one thing. understanding what to put in it is quite
>>>>> another.
>>>>>> I have ridden many 100k miles with wheels tensioned as described
>>>>>> without needing to re-true them or to replace cracked rims. These
>>>>>> have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
>>>>>> and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
>>>>>> ride the latter as do most of my fellow riders, ones who do not see
>>>>>> themselves as professional like racers..
>>>>>> When riding rough roads such as described in rec.bicycles.rides "Last
>>>>>> chance road", I and my bikie friends wonder if the light weight "with
>>>>>> it" crowd ever experience roads that are demanding on 36-spoke wheels.
>>>>>> http://tinyurl.com/2uc6tb
>>>>>> Dings in rims also come from insufficient inflation, a parallel to
>>>>>> insufficient spoke tension in supporting loads.
>>>>>> http://geocities.com/rayhosler/slideshow.html
>>>>>> Ride bike!
>>>>> red herring.
>>>> This is the dilemma that many people have:
>>>> They want advise on wheels and they look for an expert's opinion.
>>>> There are two guys who respond. One says: "wheel X with Y
>>>> characteristics is ideal." The other one says: "wheel P with Q
>>>> characteristics is ideal" both offer contradictory info with some
>>>> technical and inaccessible explanations for non engineers.
>>>> so, people have to decide which poster to believe. Poster XY has
>>>> published a book that is often referred to by bicycle people who
>>>> regularly build and sell wheels, shop owners, cyclists, and other
>>>> sport aficionados. Poster XY also post pictures in which he rides
>>>> with XY wheels in dirt roads, endless hills, tours of Europe, and post
>>>> pictures of his friends riding XY wheels with the same
>>>> characteristics. Poster XY is a regular consultant for Avocet, and
>>>> gets hired to test the products. In other words, poster XY has
>>>> established a solid reputation as an expert in the field and can site
>>>> a history of expertise and product testing. Moreover, Poster XY
>>>> doesn't appear to be affiliated or to receive compensation for many of
>>>> the ideas or products that he endorses.
>>>> Now, Poster PQ post under a pseudonym. So we don't know if he has ever
>>>> published anything. The regular wheel builders in the community and
>>>> the shop owners do not seem to endorse him. We don't know if he rides
>>>> what he claims to support and has in no established credibility.
>>>> It is possible that PQs arguments are all valid. But, for those who
>>>> lack expertise to understand the explanations, credibility is
>>>> important. It is like reading a research paper with no notes and
>>>> references vs one in which all the referred information is noted,
>>>> referenced and backed.
>>>> When people disagree with poster PQ, he becomes verbally abusive in
>>>> frustration.
>>>> If poster's PQ arguments were valid, it is very unfortunate. His lack
>>>> of credibility prevents his knowledge from being disseminated. Is
>>>> there any way that poster PQ can back up his arguments by citing the
>>>> millions of wheels that he has built for friends and customers? Can ha
>>>> document the millions of miles that he has biked on his wheels? Can
>>>> he cite companies that have consulted with him and referred to his
>>>> ideas?
>>>> I think that poster PQ needs to find a way to document that his ways
>>>> have resulted in thousands of wheels being built, thousands of miles
>>>> being ridden and a following from other aficionados. If he could build
>>>> that kind of reputation, then we could have more interesting
>>>> exchanges.
>>>> I, myself have built wheels following poster XY with great success. In
>>>> fact, being a fatso and a cheapskate, I like XY's ideas, because they
>>>> are cost effective and durable and provide many miles of riding. In
>>>> fact, my bikes have inexpensive boring looking wheels a la XY. Would I
>>>> build wheels following PQ's advise? Not now, based on his current
>>>> reputation.
>>>> Just my thoughts,
>>>> Andres
>>> whether or not you like pq's style really isn't the issue. if you don't
>>> like it, don't read it. instead, let's look at the, er, "success" of
>>> xy's schtick and how it depends on audience.
>>> if the audience doesn't know all the technical facts, they rely for
>>> judgment on the nature of presentation, appeal to alma mater authority
>>> and whether the relatively small proportion of things they /can/ test
>>> actually work. in the case of wheel building technique, xy's method
>>> does indeed work. "stress relief" as a process "works" in that it
>>> builds stable reliable wheels. but /not/ for the reasons stated! now,
>>> how would a lay person know the difference? the limit of the typical
>>> lay person's ability to follow the arguments presented depends on:
>>> 1. presentation style
>>> 2. appeal to alma mater authority
>>> 3. success in follow wheel build instructions.
>>> however, /if/ you're a techie and you want to follow the engineering
>>> arguments in xy's book, you find all kinds of problems.
>>> there are many, but they include:
>>> 1. use of the wrong stress/strain graph to explain spoke deformation.
>>> 2. use of the above to construct a "stress relief" theory - which also
>>> takes no account of the body of fatigue research accumulated over more
>>> than 100 years.
>>> 3. misattribution of rim cracking to anodizing based on an inappropriate
>>> dye penetrant test.
>>> 4. misrepresenting a load calculation to be a strength calculation.
>>> 5. neglecting spoke stiffness when attempting to calculate tensiometer
>>> deflection.
>>> and so on.
>>> the point is, under /technical/ scrutiny, there are problems ranging
>>> from simple mistakes through to outright fabrication. but how will a
>>> lay person know that and therefore be able to judge? instead, again,
>>> they're relying on
>>> 1. presentation style
>>> 2. appeal to alma mater authority
>>> 3. success in follow wheel build instructions.
>>> and are therefore susceptible to suggestion if the "expert" wants to
>>> extrapolate credibility.
>>> which leads to examination of the audience. xy has chosen to promote
>>> themselves to a carefully selected audience. the success of that is a
>>> matter of human nature since the selected target audience has no way of
>>> easily determining the truth.
>>> as an example, there are regularly cases where individuals impersonate
>>> doctors.
>>> http://www.signonsandiego.com/uniontrib/20060929/news_7m29raupp.htmlh...
>>> these individuals talk the talk, are highly convincing, even hold down
>>> jobs, in some cases for years. but in reality, they're frauds. they're
>>> very clever people exploiting human gullibility and reliance on "expert"
>>> status, but frauds nonetheless.
>>> another example would be computer hackers. a true technical "crack" is
>>> pretty geeky and hard to achieve. so most break-in's don't occur that
>>> way, most system break-in's occur via "social engineering". iow,
>>> talking a convincing talk to someone sufficiently gullible that they
>>> give away the information necessary to gain system access. and this
>>> happens all the time. that's why "phishing" works.
>>> bottom line, doctor impersonators don't show up at medical symposiums
>>> and try to present research to /real/ experts - they'll be discovered in
>>> no time. instead, they
>>> ...
>>> read more ?
>> Problem is that the other techies in the group seem to agree with XY's
>> theories and not with PQs theories. In fact, a couple of the techies
>> that support XY are often referred to in bicycling magazines work at
>> respectable bike shops and are also well known experts. Yet, most of
>> the other techies do not agree with PQ.
> here's the problem with that argument - none of these "techies" spotted
> any of the problems in "the book" before. if they're such reliable
> experts, why not?
>> PQ argues that the other techies are not really techies and don't know
>> what they are talking about. But how are the inexperienced suppossed
>> to know that PQ is right? And, what is worng with the other techies?
>> have they been so brain washed but XY that they cannot differentiate
>> good from bad? Well, I would doubt it. some of the techies work on
>> wheels using XY's approach and PQ's approach daily. In fact, since
>> they are bike shop mechanics, they can actually compare the two
>> approaches in their daily work. They end up favoring XY's, because
>> they see less failure.
> but the wheel build practice is good. that's been said repeatedly. and
> it predates the author by at least half a century. it's the proposed
> theory that's rubbish. it's based on misunderstanding and underinformed
> presumption. you don't have to take any body's word for it - you can
> see for yourself. check out the wheel load calcs - no accounting for
> wheel strength there. check out the tensiometer math - no accounting
> for spoke stiffness there. check out the stress/strain graph cited for
> "stress relief" theory, then compare it with the real stress/strain
> graphs at the back. real spokes show no strain aging. can't build a
> theory using strain aging as a deformation mechanism if it doesn't exist.
>> In my case, I have have bought bicycles that do not come up with XY's
>> equipment. they usually come with the latest most technologically
>> advanced stuff that advertisers will claim to offer. As some of the
>> equipment fails and I need to repair or replace it, I go with XY's
>> suggestions since they are cheaper, easier and more durable.
>> The doctor's example is a good one. I have an illness. I look for
>> treatment and there are lots of references to Xs treatment. In fact,
>> there are pictures of patients of X that have been treated by him and
>> seem to be better. X has published a book about his treatment, and is
>> often referred to by other doctors as an expert in the field. Other
>> doctors prescribe his treatment with success. X works at a well
>> established hospital, consults for a respected pharma and yet, he
>> doesn't seem to promote a certain brand or looking to make a buck. The
>> other doctors that prescribe X's treatment are also well established
>> and work for major clinics in the country.
>> Another individual "Y" of unknown qualifications claims that while X's
>> treatment works it is based in wrong principles, is old fashioned and
>> there are better treatments. Although, he cannot find support among
>> the other experts about his claims or the alternative treatment that
>> he is proposing. When other doctor's challenge Y and tell him that X
>> is right on, Y tells the other doctors that they don't know what he is
>> talking about. What shall the choice of doctors of the lay person be?
>> Of course, there are geniuses in the world that go against the current
>> and it turns out that they are right. Maybe, Y and PQ are
>> misunderstood geniuses.Who knows. All I can say is what I often tell a
>> student that doesnt' like me and wants to plot something against me. I
>> usually say that if he doesn't like me, but the rest of the class
>> does, the chances of being able to subvert my authority are slim. On
>> the other hand, if he can get some allies then, a larger group can
>> subvert my authority. I tell the same thing to my employees. If one
>> employee has a grievance against another one that everyone seems to
>> like and get along with, the chances of people listening to his or her
>> grievance are slim. The same applies to knowledge. If someone wants to
>> challenge a well established authority, then he needs some support. It
>> the challenger cannot get support from experts or demonstrate
>> objectively that the new knowledge is better, then he has a slim
>> chance of being listened to and a greater one of being labeled a
>> wacko. As I said, maybe the challenger is a misunderstood genius.
>> However, for a genius to waste his breath and be labeled a wacko for a
>> mere bike wheel is hardly worth it to me.
> so shut up and let you enjoy having smoke blown up your kilt in peace?
> whatever floats your boat dude! but i doubt you'd feel the same if
> someone started posting wrong, but pseudo "expert" information on a
> subject on which /you/ happened to have detailed and specific knowledge
> to the contrary. especially if they were doing it as a means of selling
> you something.
Actually, the subjects that I have expertise in, I can site sources
that will back up my knowledge, evidence that something that I propose
works, colleagues who have tried using the same techniques with
positive results. If someone presented pseudo expert information, and
they often do in my field, I can pretty much articulate the reasons
for, in my field, XY's arguments are wrong. I can site my own work as
well as the work of others to show that something is nonsense. In
fact, I have to do this often. I never argue that I am right because I
am an expert and therefore I know that the other dude is a "pseudo".
If i did that I would be laughed out of my profession. I often have to
refer to other established practitioners to back up my contentions.
With regards to XY vs PQ in wheel building, there seems to be nobody
that PQ can refer to except himself who claims that XY is a pseudo
expert. IF a pseudo expert in my field presents a theory that all the
other experts buy into and I am the only one that disagrees with, then
I cease to be the expert. This is referred to as paradigm shift. Once
the accepted knowledge in a field is that XY's theories are valid,
then XY's theories represent the dominant paradigm in wheelbuilding.

in terms of wheel assembly, they represent industry practice that
existed from /way/ back. in terms of theory, a lot of it is b.s.
"dominant paradigm" comes from relentless self-promotion to a selected
audience that has never bothered to check the math or crack open a
materials book. [references!] if these theories of "stress relief",
were presented to a symposium of materials experts, they laugh their
asses off. etc.

Quoted message said:

For the dominant paradigm to shift, PQ will have to cite experts that
support PQ's theories.

so what does the ability to successfully assemble a wheel tell you about
fatigue in non-strain aging materials? what does it tell you about
pre-stressed structure theory? what does it tell you about tensiometer
math? the point is, "credibility" in wheel assembly is /NOT/
credibility in engineering theory! that's the mistake of your argument

I have no idea, but this is not a theoretical engineering discussion
group.

sorry, i must have been mistaken. when i saw "tech" in the group
address, i wrongly assumed the intent was not for idle freakin' chit
chat, politics and b.s. masquerading as "expertise".

Quoted message said:

I know that theory and practice are related, and there are
engineers that are interested in bicycle wheels and physics forces of
bicycle riding. some are posters in this group. some may be posters or
component developers in other groups. so, are there any engineers,
physicists, mathematicians that support PQ in statying that XY's
engineering claims are nonesense?

i ask again, where are these experts that have spotted and discussed the
mistakes in "the book"? unless you're denying the mistakes of course.

Quoted message said:

Are XY and PQ the only two
individuals with expertise in this subject. we know that XY is an
engineer. Is PQ also an engineer?

no, he's a materials guy. you know, one of those sad pathetic
individuals doomed to suffer the constant disappointment of having to
mop up after the so-called "engineers" who never bother to attend
materials lectures because there weren't enough credits to make it worth
their while, and material's just material so who cares how the stuff
actually works anyway. oh, the widget broke? must be the material.
couldn't possibly be the wonderful perfect design. no siree bob.
because engineers know all about this stuff. and engineers actually
/did/ attend materials lectures. even when they didn't.

Quoted message said:

jim beam said:

Ben C said:

On 2007-07-22, [email hidden] <[email hidden]> wrote:
[...]
> Problem is that the other techies in the group seem to agree with XY's
> theories and not with PQs theories.
If you read between the lines a bit the disagreements between XY and PQ
on how to actually build a wheel are not actually so great.

except that i'm not interested in telling people how to build wheels. i
/am/ interested in making sure people correctly understand materials
theory though,

You want to teach us material's theory? How do we know that you are
qualified to teach it? Again, an expert in a field must be able to
note his claims with credibility, citations past accomplishments, etc.
Is there anyone else in this group that knows about materials theory
that can substantiate your claims? Any engineers or physicists here
that know about materials theory that can agree that JB is talking
nonesense? Are you the only expert that has figured this out and you
are misunderstood?

Andres

did you bother to look up the things i pointed out in "the book"?
thought not.