Spoke tension meter

[[email protected]]

Sheldon Brown writes:

>>> Back in the '70s and early '80s, nipples pulling through the rim
>>> were exceedingly uncommon, and the usual cause of spoke breakage
>>> was insufficient spoke tension. Tensiometers were not generally
>>> available, and John provided a useful service by offering a way an
>>> inexperienced wheelbuilder could get some idea of correct spoke
>>> tension.

>> I am not aware of spoke failure caused by insufficient tension.
>> How does that occur and for what mechanical reason?

> Fatigue. I know you seem to think that the only cause of spoke
> fatigue is inadequate stress relief. You may even be correct in
> this, and these failures may result from the fact that it's
> impossible to stress relieve spokes that have too low an initial
> tension.

I have no doubt that spoke failures are from fatigue, few are
otherwise and are obvious because they result from crashes. What I
want to know is what is the mechanism that cases spokes with low
tension to fail more than ones with high tension. This claim has been
made often but I have not seen a correlation between low tension and
spoke failure. Fatigue failures after all are the result of cyclic
loads operating near the yield stress of the spoke. As is apparent,
spokes are not that highly stressed from tension so their failures
occur at points where residual stress added to tension reach that
level. They do not break at the places where tension induced stress
is highest, in the slender part of a swaged spoke. Reducing stress at
the common failure points is where stress reliving makes the
difference.

> I do know that back before you explained the metallurgy of stress
> relief in spokes, wheels with low tension and stainless spokes
> suffered fatigue failure much more often than wheels with higher
> tension.

I don't believe it is related to tension but rather a poor build with
no attention to spoke line and stress relief. I recall only that some
riders had rattling spokes that they kept from loosening further by
tubular glue in the nipple sockets. They did not have any more spoke
failures than tight wheels but then I can't say that my sampling was
broad enough to prove a trend.

> (Despite an imperfect understanding of the microstructural results
> of stress relieving, it is a practice that good wheelbuilders have
> followed for many decades, even if they called it by another name.)

And I believe "good wheel builders" are the cause of fewer failures
than in wheels built with low tension.

[email protected]

 

[[email protected]]

On Thu, 16 Jun 2005 17:24:58 GMT, Joe Riel
<[email protected]> wrote:

>Joe Riel <[email protected]> writes:
>
>> I believe that there is a lot less lean than people imagine.
>> Certainly one can exaggerate the lean, but when you are
>> doing it naturally, the bike doesn't move all that much.
>> Certainly the total horizontal motion of the top tube is
>> less than 12 inches (side to side).
>
>Allow me to revise this. It may be a bit more than 12 inches side to
>side. To estimate how much I tilt the bike, I attached a metal
>rod to the seat stay. The lower end of the rod was near the ground.
>I then bent the rod to an appropriate angle, climbed a hill, listening
>for the tip to scrape the ground, then rebent it so that it would only
>occasionally scrape during slightly exagerrated, but not unrealistic,
>out-of-the-saddle climbing. I then measured how far I had to lean the
>bike from vertical for the tip to scrape. Seven inches. So a
>ballpark figure for total side to side movement is 14 inches.
>Undoubtedly some people will do more than this. My top tube is 31
>inches off the ground.
>
>To check the effect of spoke tension, I leaned the bike to the right,
>against a wall at that angle, stood, facing backwards, on the left
>side of the bottom bracket, and reached down to pluck a lower right
>hand side spoke. I could detect no significant change (less than a
>semitone) between that and with the bike unloaded. As expected there
>was a clear decrease in the pitch of the left side bottom spokes.
>
>Joe

Dear Joe,

I'd like you a lot better if you didn't make me feel so
dim-witted with your practical approach.

The only improvement that I can think of would be to mount
trailing training wheels on both sides just loose enough
that they'd be pushed up and stay up whenever they touched
the ground. And that would be a lot more fuss than your
approach for a very dubious improvement.

With a top-tube 31" high that leans 7" to one side, it
sounds as if your bike is tilting about 6.5 degrees to
either side, rolling back and forth through an arc of 13
degrees.

Of course, you may be an exceptionally steady rider, but
this is the first time that I've seen any actual
measurement, so I plan to take 13 degrees as a typical
figure until someone shows otherwise. And you've offered a
method that anyone can use if they think that they sway a
lot further.

Thanks,

Carl Fogel

 

[Joe Riel]

[email protected] writes:

> The only improvement that I can think of would be to mount
> trailing training wheels on both sides just loose enough
> that they'd be pushed up and stay up whenever they touched
> the ground. And that would be a lot more fuss than your
> approach for a very dubious improvement.

Training wheels, alas, aren't part of my junior scientist kit.
Aluminum rods from a discarded blind are. I've used the
same technique to measure lean angle when cornering.

> With a top-tube 31" high that leans 7" to one side, it
> sounds as if your bike is tilting about 6.5 degrees to
> either side, rolling back and forth through an arc of 13
> degrees.

Better get that slide rule recalibrated; arcsin(7/31) = 13 degrees.
So total roll is 26 degrees.

> ... you've offered a
> method that anyone can use if they think that they sway a
> lot further.

That was the idea---results must be readily reproducible. The only
tricky part was ensuring that the rod didn't move on its own. Masking
tape wasn't strong enough. I bent the top of the rod around the
mounting bolt of the rear brake, so that it had some resistance to
twisting. The middle was wedged under the quick-release lever. I
used flat cord to lash it to the seat stay.

Joe

 

[Sheldon Brown]

Jobst Brandt asked:

>>>I am not aware of spoke failure caused by insufficient tension.
>>>How does that occur and for what mechanical reason?
>
I replied:
>
>>Fatigue. I know you seem to think that the only cause of spoke
>>fatigue is inadequate stress relief. You may even be correct in
>>this, and these failures may result from the fact that it's
>>impossible to stress relieve spokes that have too low an initial
>>tension.
>
Jobst:
>
> I have no doubt that spoke failures are from fatigue, few are
> otherwise and are obvious because they result from crashes. What I
> want to know is what is the mechanism that cases spokes with low
> tension to fail more than ones with high tension. This claim has been
> made often but I have not seen a correlation between low tension and
> spoke failure. Fatigue failures after all are the result of cyclic
> loads operating near the yield stress of the spoke. As is apparent,
> spokes are not that highly stressed from tension so their failures
> occur at points where residual stress added to tension reach that
> level. They do not break at the places where tension induced stress
> is highest, in the slender part of a swaged spoke. Reducing stress at
> the common failure points is where stress reliving makes the
> difference.

I'm not a materials scientist, but the observed failure rate of
undertensioned spoke in my experience convinces me that there is a
causal relationship. I can't definitively state the cause, but can
offer a couple of surmises:

The motion of the spoke elbow in the hub flange may be involved. This
doesn't happen in a properly tensioned wheel.

With some trepidation, I'll also suggest that the "hub hanging from the
upper spokes" model might actually obtain with a wheel with very slack
spokes. This could cause the load to be carried by fewer spokes at a time.
>
> And I believe "good wheel builders" are the cause of fewer failures
> than in wheels built with low tension.

Did you really write that "sentence?" ;-)

Sheldon "I Know You Don't Like Emoticons, But..." Brown
+-------------------------------------------------------+
| The computer can't tell you the emotional story. |
| It can give you the exact mathematical design, |
| but what's missing is the eyebrows. -- Frank Zappa |
+-------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[[email protected]]

On Thu, 16 Jun 2005 19:23:24 GMT, Joe Riel
<[email protected]> wrote:

>[email protected] writes:
>
>> The only improvement that I can think of would be to mount
>> trailing training wheels on both sides just loose enough
>> that they'd be pushed up and stay up whenever they touched
>> the ground. And that would be a lot more fuss than your
>> approach for a very dubious improvement.
>
>Training wheels, alas, aren't part of my junior scientist kit.
>Aluminum rods from a discarded blind are. I've used the
>same technique to measure lean angle when cornering.
>
>> With a top-tube 31" high that leans 7" to one side, it
>> sounds as if your bike is tilting about 6.5 degrees to
>> either side, rolling back and forth through an arc of 13
>> degrees.
>
>Better get that slide rule recalibrated; arcsin(7/31) = 13 degrees.
>So total roll is 26 degrees.
>
>> ... you've offered a
>> method that anyone can use if they think that they sway a
>> lot further.
>
>That was the idea---results must be readily reproducible. The only
>tricky part was ensuring that the rod didn't move on its own. Masking
>tape wasn't strong enough. I bent the top of the rod around the
>mounting bolt of the rear brake, so that it had some resistance to
>twisting. The middle was wedged under the quick-release lever. I
>used flat cord to lash it to the seat stay.
>
>Joe

Dear Joe,

Alas, my spreadsheet is dreadfully accurate.

My dim-witted mistake was to get caught up in the fact that
the 31-7-31 is faintly isoceles, not a right triangle, so a
31/7 right triangle might not be accurate to sufficient
digits--horrors!

I cleverly split it into a pair of 3.5/31 triangles, back to
back, drew a handsome a diagram, re-labeled it correctly,
put the details into the wrong cells of my spreadsheet,
found the right cells, cross-checked my result carefully by
fooling with the radius, circumference, and 360 degrees,
doubled the result to get the correct angle for 7" . . .

.. . . and forgot that the 7" was only half the tilt.

So, adding the slight fudge factor necessary to include the
bike rolling to both sides . . . 26 degrees, not 13!

Gotta go now--I'm trying to figure out how to calculate the
approximate volume of a light bulb before Mr. Edison fills
the bulb with water and pours the water into a graduated
cylinder.

He thinks like you.

Carl Fogel

 

[[email protected]]

Sheldon Brown wrote:

> I never said anything about "sport" bikes.

It is pointless to compare the town bikes that Herrn & Frau Schmidt
ride to the Konditorei, because, after all, they're riding the same
bikes now as they were thirty years ago.

> I never said anything about cycling as a "sport." I personally don't
> view it that way, though others do.

No, I said it was a sport. Serious cycling AKA simply "cycling" is a
sport. Riding a bicycle for transportation is not cycling; that doesn't
mean it is not serious or important, but it is not cycling.

> That's not to say that cycle racing is not a sport, as is automobile
> racing or rifle shooting, but that doesn't necessarily mean that
> bicycles, cars or rifles are necessarily "sporting" equipment.

Bicycles are only sporting equipment when they are used for sport.

> I understand that this is your definition, but it isn't mine.
>
> Most of the world's cyclists can't afford a motor vehicle. They matter.

But they are not serious cyclists, they are people in serious need of
cheap transportation, which a bicycle fills best.

> If their bikes become unusable due to, say, spoke breakage, the
> consequence is serious. They may not be able to get to work on time,
> and their livelihood may be at risk.

(Ironically I have had that argument with local park officials trying
to get them to snow plow the local bike path. They angrily insist the
trail is purely recreational, ignoring the people who use it for
commuting because bicycles are their only means of transportation.) But
that does not mean they are serious cyclists, it means that they are
seriously dependent on their bicycles for transportation. Sometimes
semantics matters when people are trying to communicate.

I would be interested in knowing what distinctions there are in other
languages between people who use bicycles for transportation and those
who use them for sport. In English, I think the distinction would be
bicyclist or bicycle rider vs. cyclist, in German, IIRC, it would be
Radfahrer vs Rennfahrer (meaning racer- seems like maybe there's
another word in between that I don't remember since my German was
always lousy- I think I might have used Tourist).

> For recreational cyclists, the stakes are much lower. They may need to
> use their cell phone to call for a pickup, and lose the pleasure of
> their recreation for a day or two.

The stakes may or may not be lower, but to rephrase, there is a
difference between being a serious cyclist and someone who rides a
bicycle for a serious purpose.

> I think many folks on this newsgroup tend to focus too narrowly on
> sporty bicycles, but they are a very small percentage of the world's
> bicycles.

I'm sure you're right about this- our focus here is narrow. I don't
think it's *too* narrow, though; it just reflects the common interest
of the ng. If there were more people interested in city bikes, the
focus would shift.

 

[Benjamin Lewis]

[email protected] wrote:
>
> Sheldon Brown wrote:
>
>> I never said anything about "sport" bikes.
>
> It is pointless to compare the town bikes that Herrn & Frau Schmidt
> ride to the Konditorei, because, after all, they're riding the same
> bikes now as they were thirty years ago.
>
>> I never said anything about cycling as a "sport." I personally don't
>> view it that way, though others do.
>
> No, I said it was a sport. Serious cycling AKA simply "cycling" is a
> sport. Riding a bicycle for transportation is not cycling; that doesn't
> mean it is not serious or important, but it is not cycling.

Since when?

If you enjoy it enough, is it cycling then?

> I would be interested in knowing what distinctions there are in other
> languages between people who use bicycles for transportation and those
> who use them for sport. In English, I think the distinction would be
> bicyclist or bicycle rider vs. cyclist,

I've always considered the terms synonymous. After all, "cyclist" is just
a shortening of "bicyclist".

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber

 

[Jay Beattie]

"Sheldon Brown" <[email protected]> wrote in message
news:[email protected]...
> I wrote:
> >
> >>I used to use this system myself, before I got a tensiometer
(I made a
> >>cassette tape with a couple of piano notes on it, since the
shop I
> >>worked at at the time didn't possess a piano.)
>
> Carl Fogel wrote:
>
> Dear Sheldon,
> >
> > Surely Harris Cyclery is equipped with a Park Tools
> > Spoke-Tuning Piano or a Hozan Harpsichord to check the
> > tensiometer, but I can't find the part number for either
> > instrument.
>
> Dear Carl,
>
> The cassette system was used when I worked at a different shop.
>
> Here at Harris Cyclery we have a 4 manual Aeolian-Skinner pipe
organ for
> this. I usually use the "diapason" stop.

Boston snob! Get the giant Wurlitzer with the monkey stop -- you
know, where the little monky bangs the cymbals. That's a crowd
pleaser and a must-have for any bicycle shop. You can even get
the optional tire inflater stop. -- E. Power Beattie.

 

[jim beam]

[email protected] wrote:
> Sheldon Brown writes:
>
>
>>>>Back in the '70s and early '80s, nipples pulling through the rim
>>>>were exceedingly uncommon, and the usual cause of spoke breakage
>>>>was insufficient spoke tension. Tensiometers were not generally
>>>>available, and John provided a useful service by offering a way an
>>>>inexperienced wheelbuilder could get some idea of correct spoke
>>>>tension.
>
>
>>>I am not aware of spoke failure caused by insufficient tension.
>>>How does that occur and for what mechanical reason?
>
>
>>Fatigue. I know you seem to think that the only cause of spoke
>>fatigue is inadequate stress relief. You may even be correct in
>>this, and these failures may result from the fact that it's
>>impossible to stress relieve spokes that have too low an initial
>>tension.
>
>
> I have no doubt that spoke failures are from fatigue, few are
> otherwise and are obvious because they result from crashes. What I
> want to know is what is the mechanism that cases spokes with low
> tension to fail more than ones with high tension. This claim has been
> made often but I have not seen a correlation between low tension and
> spoke failure.

oooh, that's a good one! so why do you advocate such high spoke
tension??? mystery tension that you can't reveal?

> Fatigue failures after all are the result of cyclic
> loads

correct

> operating near the yield stress of the spoke.

absolutely *not* correct. look at an s-n curve some time.

> As is apparent,
> spokes are not that highly stressed from tension so their failures
> occur at points where residual stress added to tension reach that
> level.

ah, the amazing degree of misconception is revealed. no jobst, spokes
fatigue where cyclic strain is greatest. absolutely by definition. if
any component fatigues at any location consistently, it is the most
absolute proof you'll ever get that that location is straining as a
result of local stress, regardless of whether some engineer "thinks"
it's the most highly strained location or not. /if/ there is residual
stress, that affects initiation in that the cyclic component is shifted
up or down the stress axis, but the deviation on the strain axis remains
the same.

but let's get back to fundamentals: you've presented absolutely no proof
of residual stress. indeed, browsing one of your web sites, your
diagrams of "residual stress" resulting in bent spoke elbows show a
neutral plane in the mid point of the material. that's truly amazing!!!
spokes are bent on a mandrel, so the neutral plane is at the bending
mandrel interface!!! the fact that you've formulated this "residual
stress" theory based on this quite astounding error makes your whole
theory a farce.

> They do not break at the places where tension induced stress
> is highest,

absolutely yes they do. the highest tension [and therefore strain]
tension is in the skin of the spoke where it's being subjected to
bending. that's why surface condition of that skin is so vital in
fatigue mitigation.

> in the slender part of a swaged spoke.

that's a butted spoke if you want to speak in generic [appropriate]
terms. see above. by definition, if a spoke's not fatiguing at the
butt, it's not experiencing the highest cyclic stress. or strain.
trying to argue otherwise simply illustrates how shallow is your
understanding of fatigue principles.

> Reducing stress at
> the common failure points is where stress reliving makes the
> difference.

you've presented no proof that you're achieving metallurgical "stress
relief" or that it's even present. in fact, the supposition that it
/is/ present is based on a gross misconception. add to that the fact
that you don't understand deformation theory or fatigue or fracture
mechanics, and you really start to look like a chump making statements
like that. oh, and of course, let's conveniently overlook trivialities
like any possible effect of improved materials while we're about it
shall we?

>
>
>>I do know that back before you explained the metallurgy of stress
>>relief in spokes, wheels with low tension and stainless spokes
>>suffered fatigue failure much more often than wheels with higher
>>tension.
>
>
> I don't believe it is related to tension but rather a poor build

what is a symptom of poor build other than tension irregularities?

> with
> no attention to spoke line and stress relief.

"spoke line" corrections can make fatigue worse by increasing
dislocation density, introducing surface irregularities and
/introducing/ residual stress where none existed before. you just don't
understand the big picture.

> I recall only that some
> riders had rattling spokes that they kept from loosening further by
> tubular glue in the nipple sockets. They did not have any more spoke
> failures than tight wheels but then I can't say that my sampling was
> broad enough to prove a trend.

yes, this is the same selective memory that "forgot" to mention that
your so-called 300,000 mile "fatigue-proof" wheels had indeed broken
multiple spokes. funny how inconvenient data points can be so easily
overlooked, isn't it?

>
>
>>(Despite an imperfect understanding of the microstructural results
>>of stress relieving, it is a practice that good wheelbuilders have
>>followed for many decades, even if they called it by another name.)
>
>
> And I believe "good wheel builders" are the cause of fewer failures
> than in wheels built with low tension.

so improved materials still don't figure in your world then jobst? good
thing engineers don't depend on materials to do their job. oh, wait....

>
> [email protected]

 

[jim beam]

Luns Tee wrote:
> In article <[email protected]>,
> jim beam <[email protected]> wrote:
>
>>slack spokes are not intrinsically less strong, and as you point out,
>>their biggest problem is tendency to loosen, but there /is/ a
>>reliability problem with them. it's caused by exaggerated bending as a
>>result of their interaction with their crossing partner. spokes
>>typically fatigue at the elbow as a result of bending - they are not
>>axially loaded. if the motion they experience is exaggerated because of
>>excessive [slack] spoke movement, and even further exaggerated by their
>>[still taught] crossing partner creating even more lateral movement, the
>>[bending] strain they experience at the elbow increases and their
>>fatigue life correspondingly decreases.
>
>
> If there were any truth to this, then left side spokes on rear
> wheels would universally fatigue more than right side spokes do. My
> experience with fatigued spokes has been consistently the opposite. My
> experience with fatigued spokes also ended with stress releiving the
> surviving spokes on the wheels that had failures, something which
> should have made no effect according to your movement theory.
>
> -Luns

well, spokes /do/ fatigue because of bending - that much is evident from
their fracture surfaces. slack spokes /do/ bend more than taught ones,
that much is evident from displacement testing. i /can/ see that we
have a debate regarding terminology about what is "slack" & "loose", but
in the absence of tension numbers, i doubt we can clarify what your
pre-existing conditions were. and we also have this also somewhat
subjective discussion in the context of fundmentally differing left &
right side spoke tensions, especially when others report non-drive side
spoke failures being more common. i know my personal experience is that
of pulling more broken spokes from non-drive sides than drive sides, but
hey, that doesn't mean your spokes didn't break.

as for "stress relieving" surviving spokes, don't forget that if you're
re-using survivors, /by definition/, they are more fatigue resistant.
that's the statistical nature of fatigue. add to that the fact that you
probably paid more attention to uniform spoke tension after the repair
than the original builder did, and suddenly you have a somewhat loaded dice.

to return to my original premise, examination of the fracture surface on
a fatigued spoke tells you why it broke. all the elbow fractures i've
seen have clearly been the result of repeated bending strain. and the
majority of broken spokes i've seen have been from under-tensioned
wheels and/or non-drive side rears.

 

[Luns Tee]

In article <[email protected]>,
jim beam <[email protected]> wrote:
>> Fatigue failures after all are the result of cyclic
>> loads
>
>correct
>
>> operating near the yield stress of the spoke.
>
>absolutely *not* correct. look at an s-n curve some time.

Look at a Haigh Diagram some time.

-Luns

 

[[email protected]]

Benjamin Lewis wrote:
> I've always considered the terms synonymous. After all, "cyclist" is just
> a shortening of "bicyclist".

It could be argued that they are synoymous, but I think their usage in
the English language is somewhat different. The term "cyclist" is
usually used in the context of bicycling as some type of sporting or
athletic pursuit. It's not that common in general usage.

 

[Benjamin Lewis]

[email protected] wrote:

> Benjamin Lewis wrote:
>> I've always considered the terms synonymous. After all, "cyclist" is
>> just a shortening of "bicyclist".
>
> It could be argued that they are synoymous, but I think their usage in
> the English language is somewhat different. The term "cyclist" is
> usually used in the context of bicycling as some type of sporting or
> athletic pursuit. It's not that common in general usage.

Perhaps that's because commuting by bicycle is less common here. In any
accident report I've seen they call them "cyclist", without regard to
commuting vs. leisure. Similarly, in any discussion of modes of
transportation where bicycles come up, I've often seen talk of
"pedestrians, cyclists, drivers,..."

I rarely see people make the distinction that you are making, and I don't
see how it serves any purpose.

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber

 

[[email protected]]

Benjamin Lewis wrote:
> [email protected] wrote:
>
> > Benjamin Lewis wrote:
> >> I've always considered the terms synonymous. After all, "cyclist" is
> >> just a shortening of "bicyclist".
> >
> > It could be argued that they are synoymous, but I think their usage in
> > the English language is somewhat different. The term "cyclist" is
> > usually used in the context of bicycling as some type of sporting or
> > athletic pursuit. It's not that common in general usage.
>
> Perhaps that's because commuting by bicycle is less common here. In any
> accident report I've seen they call them "cyclist", without regard to
> commuting vs. leisure. Similarly, in any discussion of modes of
> transportation where bicycles come up, I've often seen talk of
> "pedestrians, cyclists, drivers,..."

I'm not saying there's a law dictating how the word is used, I'm just
saying that there is a tendency to shade its meaning as I described it.
The fact that you can find usage of it in other contexts means nothing,
because spoken language is not so precise. Furthermore, I would not
claim that no commuters are cyclists under the definition I suggested;
I would only say that not all bicyclists are best described by the term
"cyclist".

> I rarely see people make the distinction that you are making, and I don't
> see how it serves any purpose.

Obviously it would serve a purpose- it would distinguish between people
who view bicycling as a sporting or athletic endeavor, and those who
don't. If there wasn't a need for such a distinction, this subthread
would have never come up.

 

[Benjamin Lewis]

[email protected] wrote:

> Benjamin Lewis wrote:
>> [email protected] wrote:
>>
>>> Benjamin Lewis wrote:
>>>> I've always considered the terms synonymous. After all, "cyclist" is
>>>> just a shortening of "bicyclist".
>>>
>>> It could be argued that they are synoymous, but I think their usage in
>>> the English language is somewhat different. The term "cyclist" is
>>> usually used in the context of bicycling as some type of sporting or
>>> athletic pursuit. It's not that common in general usage.
>>
>> Perhaps that's because commuting by bicycle is less common here. In any
>> accident report I've seen they call them "cyclist", without regard to
>> commuting vs. leisure. Similarly, in any discussion of modes of
>> transportation where bicycles come up, I've often seen talk of
>> "pedestrians, cyclists, drivers,..."
>
> I'm not saying there's a law dictating how the word is used, I'm just
> saying that there is a tendency to shade its meaning as I described it.

And I'm saying I seldom see this. Perhaps it's regional, or perhaps it's
only the people you are calling "serious cyclists" that are making the
distinction.

> The fact that you can find usage of it in other contexts means nothing,
> because spoken language is not so precise. Furthermore, I would not
> claim that no commuters are cyclists under the definition I suggested;
> I would only say that not all bicyclists are best described by the term
> "cyclist".

You've made that clear, and I'm disagreeing.

>> I rarely see people make the distinction that you are making, and I
>> don't see how it serves any purpose.
>
> Obviously it would serve a purpose- it would distinguish between people
> who view bicycling as a sporting or athletic endeavor, and those who
> don't.

If you want to make a distinction between types of cyclists, why not make
yourself completely clear and use terms like "recreational cyclist" and
"commuter cyclist", rather than ambiguous terms such as "serious cyclist"
"humourless cyclist" or just "cyclist"?

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber

 

[Benjamin Lewis]

jim beam wrote:

> but let's get back to fundamentals: you've presented absolutely no proof
> of residual stress. indeed, browsing one of your web sites, your
> diagrams of "residual stress" resulting in bent spoke elbows show a
> neutral plane in the mid point of the material. that's truly amazing!!!
> spokes are bent on a mandrel, so the neutral plane is at the bending
> mandrel interface!!!

How on earth could this be a stable state?

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber

 

[[email protected]]

although a wheel with a good build needs no maintenance
i often read that-on what planet does this happen?

the tone problem! ride over to the piano or music store or naybors and
key -

i never used one-i assume that the meter is useful in working to max
tension-once in a exletive deleted the expletive deleted last spoke
lets expletive deleted and...
expletive deleted baby!

but the real deal is the five dimension game of trueing your used rim!
ain't no meter gonna do that bubba!

 

[Sheldon Brown]

Benjamin Lewis wrote:
>>>
>>>>I've always considered the terms synonymous. After all, "cyclist" is
>>>>just a shortening of "bicyclist".

A Mysterious Stranger demurred:

>>>It could be argued that they are synoymous, but I think their usage in
>>>the English language is somewhat different. The term "cyclist" is
>>>usually used in the context of bicycling as some type of sporting or
>>>athletic pursuit. It's not that common in general usage.
>>
>>Perhaps that's because commuting by bicycle is less common here. In any
>>accident report I've seen they call them "cyclist", without regard to
>>commuting vs. leisure. Similarly, in any discussion of modes of
>>transportation where bicycles come up, I've often seen talk of
>>"pedestrians, cyclists, drivers,..."
>
> I'm not saying there's a law dictating how the word is used, I'm just
> saying that there is a tendency to shade its meaning as I described it.
> The fact that you can find usage of it in other contexts means nothing,
> because spoken language is not so precise. Furthermore, I would not
> claim that no commuters are cyclists under the definition I suggested;
> I would only say that not all bicyclists are best described by the term
> "cyclist".
>
>>I rarely see people make the distinction that you are making, and I don't
>>see how it serves any purpose.
>
> Obviously it would serve a purpose- it would distinguish between people
> who view bicycling as a sporting or athletic endeavor, and those who
> don't. If there wasn't a need for such a distinction, this subthread
> would have never come up.

So, I guess I'm not a cyclist after all...who knew? ;-)

Somebody oughta tell Webster...

Main Entry: cy·clist
Pronunciation: 'sI-k(&-)l&st
Function: noun
: one who rides a cycle

I must admit that it always drive me crazy when the Boston Globe uses
the term, because in their style book it means "motorcyclist."

Sheldon "Bike Bum" Brown
+-----------------------------------------+
| Man invented language to satisfy his |
| deep need to complain. -- Lily Tomlin |
+-----------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[[email protected]]

On Fri, 17 Jun 2005 11:00:52 -0700, Benjamin Lewis
<[email protected]> wrote:

>jim beam wrote:
>
>> but let's get back to fundamentals: you've presented absolutely no proof
>> of residual stress. indeed, browsing one of your web sites, your
>> diagrams of "residual stress" resulting in bent spoke elbows show a
>> neutral plane in the mid point of the material. that's truly amazing!!!
>> spokes are bent on a mandrel, so the neutral plane is at the bending
>> mandrel interface!!!
>
>How on earth could this be a stable state?

Dear Jim and Ben,

I'm not arguing, just wondering what goes on.

If a spoke elbow is bent on a mandrel, is the idea that the
inside curve is neutral in terms of stress, while the center
is stretched into some tension (t) and the outside curve
into more tension (T)?

_______________/|
/ | |
T . . . | |
/ t __________| |
| . 0 m m m \|
| . |m m m
| . |m m m = bent on mandrel
| . | T = more residual tension
| . | t = less residual tension
0 = no residual tension

While if a spoke elbow is just bent with no mandrel, then
the no-stress line is in the center (0), the inside curve
goes into some compression (c) and the outside curve goes
into some tension (t)?

_______________/|
/ | |
t . . . | |
/ 0 __________| |
| . c \|
| . |
| . | no mandrel used
| . | t = some residual tension
| . | 0 = no residual tension
c - some residual compression

If these ASCII diagrams do show where and what kind of
residual stress occurs, where should these elbows start to
break--inside or outside of the elbow?

(I'm ignoring the flared end, but I'd be glad to hear any
gossip about whether it should break at the top or bottom.)

Carl Fogel

 

[Benjamin Lewis]

[email protected] wrote:

> On Fri, 17 Jun 2005 11:00:52 -0700, Benjamin Lewis
> <[email protected]> wrote:
>
>> jim beam wrote:
>>
>>> but let's get back to fundamentals: you've presented absolutely no
>>> proof of residual stress. indeed, browsing one of your web sites, your
>>> diagrams of "residual stress" resulting in bent spoke elbows show a
>>> neutral plane in the mid point of the material. that's truly
>>> amazing!!! spokes are bent on a mandrel, so the neutral plane is at
>>> the bending mandrel interface!!!
>>
>> How on earth could this be a stable state?
>
> Dear Jim and Ben,
>
> I'm not arguing, just wondering what goes on.
>
> If a spoke elbow is bent on a mandrel, is the idea that the
> inside curve is neutral in terms of stress, while the center
> is stretched into some tension (t) and the outside curve
> into more tension (T)?
>
> _______________/|
> / | |
> T . . . | |
> / t __________| |
> | . 0 m m m \|
> | . |m m m
> | . |m m m = bent on mandrel
> | . | T = more residual tension
> | . | t = less residual tension
> 0 = no residual tension

That appears to be Jim's idea, but I don't understand how he thinks it will
stay like this without any external forces. It seems pretty clear to me
that it will spring partially back, to the state Jobst mentions.

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber