QBP wheels

Quoted message said:

Michael Johnson said:

Quoted message said:

>>>> does anyone know for a fact whether the QBP wheels are stress
>>>> relieved? I asked Sheldon but he is not sure. Looking for value in
>>>> an old school wheel.

Quoted message said:

Quoted message said:

>>> Whether it works or not, doing it again yourself won't hurt
>>> anything. You can squeeze all the spoke pairs together yourself
>>> in less than five minutes, including the time to find some heavy
>>> gloves. That's Jobst's method. Or you can try Sheldon's
>>> method--stick a smooth crank arm into the vee of the crossing
>>> spokes and twist 'em:

http://www.sheldonbrown.com/wheelbuild.html

Quoted message said:

Quoted message said:

>>> Or you can take the wheels off, set the axle on a block of wood,
>>> put a hand on either side of the rim, and lean on it, repeating
>>> around the clock and then on the other side. That's the Mavic
>>> method, which uses your body weight and seems to produce higher
>>> tension:

http://home.comcast.net/~carlfogel/download/SpokeTension.pdf

Quoted message said:

Quoted message said:

>> The axle and block of wood method is far superior to anything
>> else. With factory wheels I always do this, retrue and build up
>> the tension between 1/2 and 3/4 turn and end up with very stable
>> wheels. Squeezing or using granny's pasta fork just doesn't pull
>> the spokes hard enough.

Quoted message said:

Quoted message said:

> I think you are mistaken in that method. If you put a tensiometer
> on the wheel and try both manual spoke stretching and the method
> you outline, you'll find they produce similar increases in spoke
> tension except that pressing down across the diameter of the wheel
> deforms it and puts permanent deformation into the wheel. By
> manually working pairs of spokes that overlap each other, there is
> only a slight radial deformation with no lateral effect.

Quoted message said:

Quoted message said:

[censored]. The axle-on-wood method works far better than the
squeeze, which rarely gets the spoke head seated fully in the
flange. The "permanent deformation" claim is also [censored]. You
just work the wheel till you see the spoke heads seat. You're
simply lying and being dogmatic for your ego. How Jobstian!

Quoted message said:

It's not the increase in tension that makes the "axle on wood"
method superior. It's the decrease in tension on the under side of
the wheel. What you're essentially doing is simulating the
unloading of spokes that naturally occurs when you ride on a wheel.

Quoted message said:

On the road, as each spoke comes to the point normal to the plane of
the ground, the rim is ever so slightly deformed to unload the
tension on the spoke. Without that tension, the static friction
force in the threads that is holding the spoke against unwinding
(and you have to have spokes with wind-up in them for this to
matter) is reduced, and the spoke twists in the nipple to relieve
the wind-up. This is why you hear the "pinging" sounds if you ride
on an unrelieved wheel.

Quoted message said:

There's a good discussion of this in Barnett's Manual, Volume 2,
page 17-24. There's also a discussion of spoke squeezing on page
16-42 that basically says the reason for squeezing is not to relieve
spoke wind-up, but to prevent spokes from breaking due to fatigue by
introducing a slight bend in the spokes where they cross. For this
purpose, I expect that Sheldon's method is superior.

Quoted message said:

A consequence of this latter contention is that it would do no good
at all to squeeze spokes on a radial lacing or on a wheel like the
recent Shimano rear wheels, that don't actually have the crossing
spokes touching each other.

If you choose to cite Barnett, how about citing "the Bicycle Wheel"
where the reason for stretching spokes is explained. It is not for
shaping spoke crossings (a place where spokes practically never fail)
but rather to relieve residual stress in spoke elbows and threads, the
cause of spoke failures in use.

Why would I bother to cite a work as an authority when I am disputing
the author's point of view?

Quoted message said:

Quoted message said:

Jobst's remark about putting a permanent deformation in the rim is
total [censored]. Doesn't happen, unless you push hard enough to taco the
wheel.

I think you'll see that a wheel bent as described will no longer be
true in a classic taco shape although not greatly so. What is more
telling is that a tensiometer will show that this method has no
advantage over manual spoke stretching, a method that does not bend
the wheel.

Umm, no. I've built multiple sets of wheels this way, and never once had
a wheel end up with a bend in it. And I do use a tensiometer when I
build wheels.

Quoted message said:

Jobst Brandt, ego-literian

Mike Johnson, skeptic

Michael Johnson said:

landotter said:

Quoted message said:

Granddaughter writes:
>>> does anyone know for a fact whether the QBP wheels are stress
>>> relieved? I asked Sheldon but he is not sure. Looking for value in
>>> an old school wheel.
>> Whether it works or not, doing it again yourself won't hurt
>> anything.
>> You can squeeze all the spoke pairs together yourself in less than
>> five minutes, including the time to find some heavy gloves. That's
>> Jobst's method.
>> Or you can try Sheldon's method--stick a smooth crank arm into the
>> vee of the crossing spokes and twist 'em:
http://www.sheldonbrown.com/wheelbuild.html

Quoted message said:

Quoted message said:

>> Or you can take the wheels off, set the axle on a block of wood,
>> put a hand on either side of the rim, and lean on it, repeating
>> around the clock and then on the other side. That's the Mavic
>> method, which uses your body weight and seems to produce higher
>> tension:
http://home.comcast.net/~carlfogel/download/SpokeTension.pdf

Quoted message said:

Quoted message said:

> The axle and block of wood method is far superior to anything else.
> With factory wheels I always do this, retrue and build up the
> tension between 1/2 and 3/4 turn and end up with very stable
> wheels. Squeezing or using granny's pasta fork just doesn't pull the
> spokes hard enough.
I think you are mistaken in that method. If you put a tensiometer on
the wheel and try both manual spoke stretching and the method you
outline, you'll find they produce similar increases in spoke tension
except that pressing down across the diameter of the wheel deforms it
and puts permanent deformation into the wheel. By manually working
pairs of spokes that overlap each other, there is only a slight radial
deformation with no lateral effect.

Quoted message said:

[censored]. The axle-on-wood method works far better than the squeeze,
which rarely gets the spoke head seated fully in the flange. The
"permanent deformation" claim is also [censored]. You just work the
wheel till you see the spoke heads seat. You're simply lying and being
dogmatic for your ego. How Jobstian!

It's not the increase in tension that makes the "axle on wood" method
superior. It's the decrease in tension on the under side of the wheel.
What you're essentially doing is simulating the unloading of spokes that
naturally occurs when you ride on a wheel.

On the road, as each spoke comes to the point normal to the plane of the
ground, the rim is ever so slightly deformed to unload the tension on
the spoke. Without that tension, the static friction force in the
threads that is holding the spoke against unwinding (and you have to
have spokes with wind-up in them for this to matter) is reduced, and the
spoke twists in the nipple to relieve the wind-up. This is why you hear
the "pinging" sounds if you ride on an unrelieved wheel.

There's a good discussion of this in Barnett's Manual, Volume 2, page
17-24. There's also a discussion of spoke squeezing on page 16-42 that
basically says the reason for squeezing is not to relieve spoke wind-up,
but to prevent spokes from breaking due to fatigue by introducing a
slight bend in the spokes where they cross. For this purpose, I expect
that Sheldon's method is superior.

I don't buy it. Last I checked spokes broke at the flange. Maybe I
don't have a kung-fu grip, because I've never been able to get spokes
seated in the flange with a hand squeeze. Yes, I've done the bend-
around thing before I dismissed it as pointless. Doing it takes time
away from important things, like aligning tire and rim labels!

On Wed, 16 Jan 2008 12:01:54 -0800 (PST), Zruk <[email hidden]>

Quoted message said:

Hi,
does anyone know for a fact whether the QBP wheels are stress
relieved? I asked Sheldon but he is not sure. Looking for value in an
old school wheel.
thanks

Dear Stan,

Since your post has revived old debates, here's a link to a post with
graphs of measured spoke tension rise for the Mavic press-on-the-rim
and the Jobst squeeze-spoke-pairs methods:
http://groups.google.com/group/rec.bicycles.misc/msg/3058f923dbf37c3b

A typical RBT poster will find that he can raise the spoke tension
about 50% higher by leaning on the rim than by hand squeezing, since
it's easy for practically anyone to press down with 100 pounds of
force on the rim, but hard for most posters to produce more than a
60-pound squeeze with the weak hand 9 times in a row around a 36-spoke
rim. (The actual maximum spoke tension rise is always less than the
applied force.)

In any case, no poster ever says drat, I must not have Jobst-squeezed,
Mavic-pressed, or Sheldon-twisted my spokes hard enough.

Cheers,

Carl Fogel

Quoted message said:

On Wed, 16 Jan 2008 12:01:54 -0800 (PST), Zruk <[email hidden]>

Quoted message said:

Hi,
does anyone know for a fact whether the QBP wheels are stress
relieved? I asked Sheldon but he is not sure. Looking for value in an
old school wheel.
thanks

Dear Stan,

Since your post has revived old debates, here's a link to a post with
graphs of measured spoke tension rise for the Mavic press-on-the-rim
and the Jobst squeeze-spoke-pairs methods:
http://groups.google.com/group/rec.bicycles.misc/msg/3058f923dbf37c3b

A typical RBT poster will find that he can raise the spoke tension
about 50% higher by leaning on the rim than by hand squeezing, since
it's easy for practically anyone to press down with 100 pounds of
force on the rim, but hard for most posters to produce more than a
60-pound squeeze with the weak hand 9 times in a row around a 36-spoke
rim. (The actual maximum spoke tension rise is always less than the
applied force.)

In any case, no poster ever says drat, I must not have Jobst-squeezed,
Mavic-pressed, or Sheldon-twisted my spokes hard enough.

Fie! Must you come here with facts when we're armed with pilsners and
conjecture! Fogel Labs, always pooping in the punchbowl!

On 2008-01-17, Michael Johnson <[email hidden]> wrote:
[...]

Quoted message said:

There's a good discussion of this in Barnett's Manual, Volume 2, page
17-24. There's also a discussion of spoke squeezing on page 16-42 that
basically says the reason for squeezing is not to relieve spoke wind-up,
but to prevent spokes from breaking due to fatigue by introducing a
slight bend in the spokes where they cross.

That's one spoke-squeezing (and why-we-have-crosses) theory I've not
heard of before. Why does a slight bend at the cross prevent breaking
due to fatigue?

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so viscious?
Because the stakes are so small.
Can't we all just get along?
I like the idea of stress releiving the wheel my self but I am a
little gun shy about truing since I have neither a tensionometer or
much experience and am afraid of botching up the wheel. I amafter all
seeking round and strong.

Zruk said:

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so viscious?
Because the stakes are so small.
Can't we all just get along?

Helmets, wheel building, and saddles are the guns, gods, and gays of
the r.b.t set. Yarr! Why do you think I put on my Ralph Reed Underoos?

Quoted message said:

I like the idea of stress releiving the wheel my self but I am a
little gun shy about truing since I have neither a tensionometer or
much experience and am afraid of botching up the wheel. I amafter all
seeking round and strong."

I'm completely unqualified to say this, but it seems virtually all
factory built wheels can take a half turn more tension. That's a broad
statement, to be sure so take with a grain of salt. If you're a
lighter rider you can probably just ride the wheels as is. If you do
try and learn the art of wheel tuning--do start small. I like to work
with 1/4 turns as units when dialing in or truing a wheel.

Stan Kurz said:

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so vicious?
Because the stakes are so small.
Can't we all just get along?

Quoted message said:

I like the idea of stress relieving the wheel my self but I am a
little gun shy about truing since I have neither a tensiometer or
much experience and am afraid of botching up the wheel. I am, after
all, seeking round and strong.

Get a good spoke wrench, you already have the rest of the equipment on
your bicycle. If in doubt, you can get the details for even starting
from scratch in "the Bicycle Wheel" and it's readily available at many
sources. For spoke length calculations, shown in the book, others
have put that into useful spreadsheets at:

http://www.sheldonbrown.com/rinard/spocalc.htm

Jobst Brandt

Jay Beattie said:

landotter said:

On Jan 17, 3:49 pm, Zruk <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so viscious?
Because the stakes are so small.
Can't we all just get along?

Quoted message said:

Helmets, wheel building, and saddles are the guns, gods, and gays of
the r.b.t set. Yarr! Why do you think I put on my Ralph Reed Underoos?

Quoted message said:

Quoted message said:

I like the idea of stress releiving the wheel my self but I am a
little gun shy about truing since I have neither a tensionometer or
much experience and am afraid of botching up the wheel. I amafter all
seeking round and strong."

Quoted message said:

I'm completely unqualified to say this, but it seems virtually all
factory built wheels can take a half turn more tension. That's a broad
statement, to be sure so take with a grain of salt. If you're a
lighter rider you can probably just ride the wheels as is. If you do
try and learn the art of wheel tuning--do start small. I like to work
with 1/4 turns as units when dialing in or truing a wheel.

Keep in mind that "factory built wheels" includes a lot of botique,
low spoke count stuff.  I have been building wheels for 30 years but
suckered into buying a sale set of FSA wheels.  They would not stay
tight (like all the spokes went slack 20 miles from home on my first
ride), so I upped the spoke tension by maybe a quarter to half turn --
and the spokes started to break -- front and rear.  So I returned the
wheels and was given a new pair that supposedly had better tension and
more nipple [censored] to prevent unwinding.  Those wheels loosened up after
ten miles, so I  put a gallon of LocTite on the nipples; threw the
wheels on another bike and sold the lot to a much lighter rider who
apparently has gotten good service out of them.  In rare instances,
upping the tension can cause problems.

By the way, back in the '70s (before the Book, even),  I tacoed a rim
while side loading it in the building process.  It was on the fine
edge of over-tension already.  Anyway, I got it back in to reasonable
true, but at the expense of even spoke tension.  So it is possible to
screw up a wheel with side loading during building -- but I still do
it, although more carefully.  The real problem back in the day was
forgetting to use the Phil supplied cup when side loading and pushing
out axles on Phil hubs.  Another big oops.  Life lesson: final tension
before beer number four (actually, it was not beer back then, but you
know what I mean). -- Jay Beattie.- Hide quoted text -

P.S. I was a little vague: the spokes started to break while I was
riding the wheel later and not during the tightening process -- which
meant that I was screwed because the nipples had to be tightened with
a socket or key from the "inside" (rim bed), and my key chain spoke
wrench was useless to get the wheel reasonably true to get home. It
was clunk, clunk, clunk through the brake pads all the way home. --
Jay Beattie.

Jay Beattie said:

landotter said:

On Jan 17, 3:49 pm, Zruk <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so viscious?
Because the stakes are so small.
Can't we all just get along?

Quoted message said:

Helmets, wheel building, and saddles are the guns, gods, and gays of
the r.b.t set. Yarr! Why do you think I put on my Ralph Reed Underoos?

Quoted message said:

Quoted message said:

I like the idea of stress releiving the wheel my self but I am a
little gun shy about truing since I have neither a tensionometer or
much experience and am afraid of botching up the wheel. I amafter all
seeking round and strong."

Quoted message said:

I'm completely unqualified to say this, but it seems virtually all
factory built wheels can take a half turn more tension. That's a broad
statement, to be sure so take with a grain of salt. If you're a
lighter rider you can probably just ride the wheels as is. If you do
try and learn the art of wheel tuning--do start small. I like to work
with 1/4 turns as units when dialing in or truing a wheel.

Keep in mind that "factory built wheels" includes a lot of botique,
low spoke count stuff.

Oh sure, my general advice is for traditional factory wheels. I don't
think I'd have the moxie to touch them fancy six spoke jobbers with
spoke tension requiring the use of a torque wrench. The veteran down
at the LBS probably wouldn't be skeered. I asked him if he used a
tensionometer, and in true Nashville fashion he said, "Naw, I'm a
geetar player, don't need one." To his credit, he used to build wheels
for a race team with a near immaculate record.

Quoted message said:

Life lesson: final tension
before beer number four (actually, it was not beer back then, but you
know what I mean). -- Jay Beattie.

I can do tension after beer four, it's just that I often have to
relace a couple times after doing the equivalent of buttoning a shirt
one hole off. ;-)

The drug of choice for really meticulous wheels is likely speed--my
neighbor used to get whacked and do calculus for fun, but I hear it's
a bit habit forming.

Quoted message said:

Stan Kurz said:

Wow; who turned up the heat?
Reminds me of the old saw: why are academic politics so vicious?
Because the stakes are so small.
Can't we all just get along?

Quoted message said:

I like the idea of stress relieving the wheel my self but I am a
little gun shy about truing since I have neither a tensiometer or
much experience and am afraid of botching up the wheel. I am, after
all, seeking round and strong.

Get a good spoke wrench, you already have the rest of the equipment on
your bicycle.

do bicycles these days come equipped with tensiometers? how odd - i've
never seen one that is. is this a jobstian palo alto fashion thing?

Quoted message said:

If in doubt, you can get the details for even starting
from scratch in "the Bicycle Wheel" and it's readily available at many
sources.

the revised edition? the one where you correct your multitude of
fundamental mistakes?

Quoted message said:

For spoke length calculations, shown in the book, others
have put that into useful spreadsheets at:

http://www.sheldonbrown.com/rinard/spocalc.htm

it's worth noting that damon gives that away for free /AND/ [most
importantly] accepts corrections/additional input. unlike jobst brandt.

Michael Johnson said:

Quoted message said:

Michael Johnson said:

>>>>> does anyone know for a fact whether the QBP wheels are stress
>>>>> relieved? I asked Sheldon but he is not sure. Looking for value in
>>>>> an old school wheel.

Quoted message said:

>>>> Whether it works or not, doing it again yourself won't hurt
>>>> anything. You can squeeze all the spoke pairs together yourself
>>>> in less than five minutes, including the time to find some heavy
>>>> gloves. That's Jobst's method. Or you can try Sheldon's
>>>> method--stick a smooth crank arm into the vee of the crossing
>>>> spokes and twist 'em:

http://www.sheldonbrown.com/wheelbuild.html

Quoted message said:

>>>> Or you can take the wheels off, set the axle on a block of wood,
>>>> put a hand on either side of the rim, and lean on it, repeating
>>>> around the clock and then on the other side. That's the Mavic
>>>> method, which uses your body weight and seems to produce higher
>>>> tension:

http://home.comcast.net/~carlfogel/download/SpokeTension.pdf

Quoted message said:

>>> The axle and block of wood method is far superior to anything
>>> else. With factory wheels I always do this, retrue and build up
>>> the tension between 1/2 and 3/4 turn and end up with very stable
>>> wheels. Squeezing or using granny's pasta fork just doesn't pull
>>> the spokes hard enough.

Quoted message said:

>> I think you are mistaken in that method. If you put a tensiometer
>> on the wheel and try both manual spoke stretching and the method
>> you outline, you'll find they produce similar increases in spoke
>> tension except that pressing down across the diameter of the wheel
>> deforms it and puts permanent deformation into the wheel. By
>> manually working pairs of spokes that overlap each other, there is
>> only a slight radial deformation with no lateral effect.

Quoted message said:

> [censored]. The axle-on-wood method works far better than the
> squeeze, which rarely gets the spoke head seated fully in the
> flange. The "permanent deformation" claim is also [censored]. You
> just work the wheel till you see the spoke heads seat. You're
> simply lying and being dogmatic for your ego. How Jobstian!

Quoted message said:

It's not the increase in tension that makes the "axle on wood"
method superior. It's the decrease in tension on the under side of
the wheel. What you're essentially doing is simulating the
unloading of spokes that naturally occurs when you ride on a wheel.

Quoted message said:

On the road, as each spoke comes to the point normal to the plane of
the ground, the rim is ever so slightly deformed to unload the
tension on the spoke. Without that tension, the static friction
force in the threads that is holding the spoke against unwinding
(and you have to have spokes with wind-up in them for this to
matter) is reduced, and the spoke twists in the nipple to relieve
the wind-up. This is why you hear the "pinging" sounds if you ride
on an unrelieved wheel.

Quoted message said:

There's a good discussion of this in Barnett's Manual, Volume 2,
page 17-24. There's also a discussion of spoke squeezing on page
16-42 that basically says the reason for squeezing is not to relieve
spoke wind-up, but to prevent spokes from breaking due to fatigue by
introducing a slight bend in the spokes where they cross. For this
purpose, I expect that Sheldon's method is superior.

Quoted message said:

A consequence of this latter contention is that it would do no good
at all to squeeze spokes on a radial lacing or on a wheel like the
recent Shimano rear wheels, that don't actually have the crossing
spokes touching each other.

If you choose to cite Barnett, how about citing "the Bicycle Wheel"
where the reason for stretching spokes is explained. It is not for
shaping spoke crossings (a place where spokes practically never fail)
but rather to relieve residual stress in spoke elbows and threads, the
cause of spoke failures in use.

Why would I bother to cite a work as an authority when I am disputing
the author's point of view?

to stroke that author's ego and bizarre sense of entitlement?

Quoted message said:

Quoted message said:

Quoted message said:

Jobst's remark about putting a permanent deformation in the rim is
total [censored]. Doesn't happen, unless you push hard enough to taco the
wheel.

I think you'll see that a wheel bent as described will no longer be
true in a classic taco shape although not greatly so. What is more
telling is that a tensiometer will show that this method has no
advantage over manual spoke stretching, a method that does not bend
the wheel.

Umm, no. I've built multiple sets of wheels this way, and never once had
a wheel end up with a bend in it.

that's because it doesn't collapse wheels if the spoke tension is not
excessive - as jobst's incorrect spoke tension technique will have you do.

Quoted message said:

And I do use a tensiometer when I
build wheels.

that's why you don't have a problem!

Quoted message said:

Quoted message said:

Jobst Brandt, ego-literian

Mike Johnson, skeptic

don't be a skeptic. this stuff is not hard. jobst's book is fine for
telling you how to lace and true a wheel. and calculate spoke length.
but don't use it for anything else - certainly not for correct spoke
tensioning. and /definitely/ not basic engineering/materials theory.

Ozark Bicycle said:

Brandt engages in the usual BS:

Quoted message said:

Granddaughter snipes from cover:

<snip>

Quoted message said:

Meanwhile, can you present technical material in a civil tone?

Has anyone else's "irony" meter exploded???

the exploding meter was the one marked "hypocrisy". the irony meter is
pegged on "delicious".

Quoted message said:

Quoted message said:

�Who are you, by the way?

WTF difference does it make, Brandt???

Quoted message said:

�It seems the rudest folks are all anonymous.

Gee, you're the rudest SOB here, but you're not "anonymous".

it's an interesting how some people are repeatedly suckered by this
whole "anonymity" decoy. "credibility" is that derived from evidencing
ability to get the facts straight and cut through the [censored], not
having to rely on one's alma mater or being breathtakingly hypocritical.

Ben C said:

On 2008-01-17, Michael Johnson <[email hidden]> wrote:
[...]

Quoted message said:

There's a good discussion of this in Barnett's Manual, Volume 2, page
17-24. There's also a discussion of spoke squeezing on page 16-42 that
basically says the reason for squeezing is not to relieve spoke wind-up,
but to prevent spokes from breaking due to fatigue by introducing a
slight bend in the spokes where they cross.

That's one spoke-squeezing (and why-we-have-crosses) theory I've not
heard of before. Why does a slight bend at the cross prevent breaking
due to fatigue?

According to Barnett, when the spokes don't have a slight bend, they are
subjected to cycles of being bent against each other and released as
they go through load/unload cycles. This constant flexing eventually
results in material fatigue. This is the contention in the manual, at
any rate.

I cannot personally vouch for the truth of the assertion, I haven't seen
the experimental data. It sounds plausible, however. Certainly more so
than the idea that momentarily /increasing/ the tension on a spoke is
going to relieve spoke wind-up. I ain't buyin' it, all self-promotion on
the part of book authors posing as authorities not withstanding. Since I
have a couple of years of 4.0 averages in engineering physics and other
mechanical engineering courses under my belt (before I discovered that I
like programming computers), I'm not entirely ignorant in this area.

Mike Johnson

Michael Johnson said:

Ben C said:

On 2008-01-17, Michael Johnson <[email hidden]> wrote:
[...]

Quoted message said:

There's a good discussion of this in Barnett's Manual, Volume 2, page
17-24. There's also a discussion of spoke squeezing on page 16-42
that basically says the reason for squeezing is not to relieve spoke
wind-up, but to prevent spokes from breaking due to fatigue by
introducing a slight bend in the spokes where they cross.

That's one spoke-squeezing (and why-we-have-crosses) theory I've not
heard of before. Why does a slight bend at the cross prevent breaking
due to fatigue?

According to Barnett, when the spokes don't have a slight bend, they are
subjected to cycles of being bent against each other and released as
they go through load/unload cycles. This constant flexing eventually
results in material fatigue. This is the contention in the manual, at
any rate.

dude, if the spokes don't break there, don't worry about it. the
crossing bends may have a theoretical weakness, but if it doesn't
manifest in practice, it's irrelevant. like jobst's pedal eye modification.

Quoted message said:

I cannot personally vouch for the truth of the assertion, I haven't seen
the experimental data. It sounds plausible, however. Certainly more so
than the idea that momentarily /increasing/ the tension on a spoke is
going to relieve spoke wind-up. I ain't buyin' it, all self-promotion on
the part of book authors posing as authorities not withstanding. Since I
have a couple of years of 4.0 averages in engineering physics and other
mechanical engineering courses under my belt (before I discovered that I
like programming computers), I'm not entirely ignorant in this area.

Mike Johnson

landotter said:

...
Oh sure, my general advice is for traditional factory wheels. I don't
think I'd have the moxie to touch them fancy six spoke jobbers with
spoke tension requiring the use of a torque wrench. The veteran down
at the LBS probably wouldn't be skeered. I asked him if he used a
tensionometer, and in true Nashville fashion he said, "Naw, I'm a
geetar player, don't need one." To his credit, he used to build wheels
for a race team with a near immaculate record....

So the wheels were responsible for the team winning almost every race?

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

Michael Johnson said:

Quoted message said:

[...] > There's a good discussion of this in Barnett's Manual,
Volume 2, page 17-24. There's also a discussion of spoke squeezing
on page 16-42 that basically says the reason for squeezing is not
to relieve spoke wind-up, but to prevent spokes from breaking due
to fatigue by introducing a slight bend in the spokes where they
cross.

Quoted message said:

Quoted message said:

That's one spoke-squeezing (and why-we-have-crosses) theory I've
not heard of before. Why does a slight bend at the cross prevent
breaking due to fatigue?

Quoted message said:

According to Barnett, when the spokes don't have a slight bend, they
are subjected to cycles of being bent against each other and
released as they go through load/unload cycles. This constant
flexing eventually results in material fatigue. This is the
contention in the manual, at any rate.

I think you'll find that spokes removed from a wheel show no kink
where they cross an interleaved opposing spoke, before or after stress
relieving. The two advantages of interleaving, something most wheel
builders do, is that spokes do not go entirely slack when riding over
rough road and a broken spoke doesn't not dangle freely and foul the
wheel regardless of which end fails.

Quoted message said:

I cannot personally vouch for the truth of the assertion, I haven't
seen the experimental data. It sounds plausible, however.
Certainly more so than the idea that momentarily /increasing/ the
tension on a spoke is going to relieve spoke wind-up.

Its the adjacent spoke that becomes unloaded from this maneuver that
untwists, the same as when a wheel is pressed against the floor on its
axle. It is the slackening spoke that untwists.

Quoted message said:

I ain't buyin' it, all self-promotion on the part of book authors
posing as authorities not withstanding. Since I have a couple of
years of 4.0 averages in engineering physics and other mechanical
engineering courses under my belt (before I discovered that I like
programming computers), I'm not entirely ignorant in this area.

Not to worry. It's what you do best and what brings in money that
should be pursued. I'm in favor of that.

Quoted message said:

Mike Johnson

Jobst Brandt

Quoted message said:

Michael Johnson said:

Quoted message said:

That's one spoke-squeezing (and why-we-have-crosses) theory I've
not heard of before. Why does a slight bend at the cross prevent
breaking due to fatigue?

Quoted message said:

According to Barnett, when the spokes don't have a slight bend, they
are subjected to cycles of being bent against each other and
released as they go through load/unload cycles. This constant
flexing eventually results in material fatigue. This is the
contention in the manual, at any rate.

I think you'll find that spokes removed from a wheel show no kink
where they cross an interleaved opposing spoke, before or after stress
relieving. The two advantages of interleaving, something most wheel
builders do, is that spokes do not go entirely slack when riding over
rough road and a broken spoke doesn't not dangle freely and foul the
wheel regardless of which end fails.

I didn't say that the spokes developed a kink where they cross. What I
said was that they are constantly flexed, i.e. bowed then unbowed, as
they are loaded and unloaded. This bowing takes place along the entire
length of the spoke and results in fatigue at the elbow, where the spoke
typically breaks. Again, according to Barnett.

If you introduce a bend in the spoke, which Sheldon's method (and the
method in Barnett, which differs only in the implement used) actually
does, then the spoke is already in a bowed shape and doesn't flex as
much as it is loaded and unloaded, thereby reducing mechanical fatigue.

Your point about interleaving, while true enough, is a red herring.

Quoted message said:

Quoted message said:

I cannot personally vouch for the truth of the assertion, I haven't
seen the experimental data. It sounds plausible, however.
Certainly more so than the idea that momentarily /increasing/ the
tension on a spoke is going to relieve spoke wind-up.

Its the adjacent spoke that becomes unloaded from this maneuver that
untwists, the same as when a wheel is pressed against the floor on its
axle. It is the slackening spoke that untwists.

So you're claiming that the rim flexes enough radially when you squeeze
some spokes to cause other spokes to go slack and unwind? I would expect
this effect to be minimal at best, especially compared to pressing on
the rim.

Mike Johnson

[email hidden said:

"]On Wed, 16 Jan 2008 12:01:54 -0800 (PST), Zruk <[email hidden]>

Quoted message said:

Hi,
does anyone know for a fact whether the QBP wheels are stress
relieved? I asked Sheldon but he is not sure. Looking for value in an
old school wheel.
thanks

Dear Stan,

Whether it works or not, doing it again yourself won't hurt anything.

You can squeeze all the spoke pairs together yourself in less than
five minutes, including the time to find some heavy gloves. That's
Jobst's method.

Or you can try Sheldon's method--stick a smooth crank arm into the vee
of the crossing spokes and twist 'em:
http://www.sheldonbrown.com/wheelbuild.html

Or you can take the wheels off, set the axle on a block of wood, put a
hand on either side of the rim, and lean on it, repeating around the
clock and then on the other side. That's the Mavic method, which uses
your body weight and seems to produce higher tension:
http://home.comcast.net/~carlfogel/download/SpokeTension.pdf

Any of these methods may produce small cracking or popping noises as
wound-up spokes untwist or seat, and you may have to re-true the wheel
a little afterward.

Cheers,

Carl Fogel

I use the inclusive "or"' of these methods. I agree that it doesn't hurt to "do it again". If fact, when I need to re-true, I do it again until the wheel is "stabilized" and true.
Using the "Mavic method" I "tacoed" only one wheel (out of over 2,000 built or worked on): old single wall low profile rear.
I have also cracked 5 rims (out of over 2,000) at the eyelets (or spoke holes) and "recycled" the rims during these procedures. 2 were FIR, 2 were Mavic, and 1 non-eyeletted Velocity Aerohead.
These 6 "failures", while frustrating and time consuming at the time, likely saved future issues with the wheels involved.
QBP wheel house is known for good quality and good value.

Michael Johnson said:

Quoted message said:

Quoted message said:

> That's one spoke-squeezing (and why-we-have-crosses) theory I've
> not heard of before. Why does a slight bend at the cross prevent
> breaking due to fatigue?

Quoted message said:

Quoted message said:

Quoted message said:

According to Barnett, when the spokes don't have a slight bend,
they are subjected to cycles of being bent against each other and
released as they go through load/unload cycles. This constant
flexing eventually results in material fatigue. This is the
contention in the manual, at any rate.

Quoted message said:

Quoted message said:

I think you'll find that spokes removed from a wheel show no kink
where they cross an interleaved opposing spoke, before or after
stress relieving. The two advantages of interleaving, something
most wheel builders do, is that spokes do not go entirely slack
when riding over rough road and a broken spoke doesn't not dangle
freely and foul the wheel regardless of which end fails.

Quoted message said:

I didn't say that the spokes developed a kink where they cross. What
I said was that they are constantly flexed, i.e. bowed then unbowed,
as they are loaded and unloaded. This bowing takes place along the
entire length of the spoke and results in fatigue at the elbow,
where the spoke typically breaks. Again, according to Barnett.

If the spoke does not change shape, how does this method alter how the
spoke flexes in use, assuming it does so? In contrast, I think you'll
find that the spokes run in an unchanging straight line to the ends
and that the slight deflection at interleaved spoke crossing moves so
slightly that it causes no perceptible sound as these points fret
against each other. In time this causes a notch in each spoke, one
that is noticeable when they are displaced past one another manually
and click back into the notch when released.

Quoted message said:

If you introduce a bend in the spoke, which Sheldon's method (and the
method in Barnett, which differs only in the implement used) actually
does, then the spoke is already in a bowed shape and doesn't flex as
much as it is loaded and unloaded, thereby reducing mechanical fatigue.

I think you'll find that there is no permanent bend introduced by
these methods, the spokes being essentially as straight as they were
fresh out of the box. What changes is the elbow bend for outbound
spokes, mainly on the left side. Improving the spoke line is best
done directly and manually before the wheel has full tension, and it
doesn't have anything to do with spoke crossings.

Quoted message said:

Your point about interleaving, while true enough, is a red herring.

Wat in particular do you mean in that respect?

Quoted message said:

Quoted message said:

Quoted message said:

I cannot personally vouch for the truth of the assertion, I
haven't seen the experimental data. It sounds plausible, however.
Certainly more so than the idea that momentarily /increasing/ the
tension on a spoke is going to relieve spoke wind-up.

Quoted message said:

Quoted message said:

Its the adjacent spoke that becomes unloaded from this maneuver
that untwists, the same as when a wheel is pressed against the
floor on its axle. It is the slackening spoke that untwists.

Quoted message said:

So you're claiming that the rim flexes enough radially when you
squeeze some spokes to cause other spokes to go slack and unwind? I
would expect this effect to be minimal at best, especially compared
to pressing on the rim.

When grasping pairs of spokes firmly, the rim moves radially inward
and partially relaxes adjacent spoke tension. As the spokes are
pulled together, they do not change length so something must move (by
the cosine of the angle). The only length change spokes is in
microns, locally at high concentrations. These changes are immaterial
to wheel alignment while radial rim flexing remains in the elastic
zone unless the wheel is too tight.

Jobst Brandt