Spoke tension meter

[jim beam]

dvt wrote:
> jim beam wrote:
>
>> 41 wrote:
>>
>>>
>>> jim beam wrote:
>>>
>>>> 41 wrote:
>>>>
>>>>> jim beam wrote:
>>>>>
>>>>>
>>>>>
>>>>>> if a component is not stress relieved shortly after initial
>>>>>> formation, additional work can add to any existing residual
>>>>>> stress, not
>>>>>> mitigate it.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Specify deltaT. Specifiy the equation from which one calculates this
>>>>> deltaT, or where it enters in any way. Specify the nature of the
>>>>> "additional work", and the conditions that determine "will" and
>>>>> "won't".
>>>>>
>>>>> I don't believe you can.
>>>>>
>>>>
>>>> eh? "T" isn't used for stress. you used it twice, so presumably it's
>>>> not a typo. you'll have to explain what are you talking about...
>>>
>>>
>>>
>>>
>>> Uh huh. I used a capital T because deltat looks like a funny word and I
>>> can't trust the spacing on Google posts. OK, "delta t" then if you
>>> like. I mean the time interval. In case that isn't clear enough, it
>>> refers to the "shortly" in your claim. The rest was perfectly clear
>>> already.
>>>
>> spell out the subject. stress is sigma. strain is percent. do you
>> mean "t" in the thermodynamic sense? do you want to discuss
>> dislocation energies? what are you getting at? spell the word of the
>> subject you're cryptically referring to. please.
>
>
> Allow me to repeat 41's earlier sentence: "I mean the time interval.
> ...it refers to the "shortly" in your claim." I think he wants to know
> how much time is allowed between the initial formation and stress relief.
>
ok, ok, appologies. i was scrambling to leave for work & didn't read
beyond the sarcasm.

as it happens, you all seem to have pretty much answered the question.
dislocations tend to move around for a little while after they have been
acivated.

 

[jim beam]

[email protected] wrote:
> Carl Fogel writes:
>
>
>>>These elongations by yielding are in the micro-inches and have
>>>negligible effect on spoke length, and therefore, tension. That
>>>the spokes "bed in" is accomplished before this stage just by
>>>tension. Therefore there is no significant change in spoke support
>>>although some people believe that this is a major factor in stress
>>>relieving. To those who believe this, I suggest they spoke up a
>>>wheel with new hubs to full tension without stress relieving, and
>>>remove a spoke to see that it is fully bedded in.
>
>
>>How does the aluminum hub know to let spokes bed in when tensioned
>>to say 200 pounds, but not to let the spokes bed in any further when
>>pairs of spokes are squeezed together to raise (in theory) the
>>tension to roughly triple that amount and to bring (in theory)
>>stainless steel spokes to near yield?
>
>
> I think you are aware of asymptotes and bedding in is one of these
> effects that asymptotically ceases after a certain stress because the
> contact area becomes large enough that no more bedding in occurs.

for a given load, that's correct, but if the load increases, the
indentation increases, even if by a small amount.

> You
> can try this by spoking a wheel tightly and stress relieve a pair of
> spokes. You will not be able to detect on the hub which spokes you
> stress relieved when inspecting the spoke hole after spoke removal.

not true. put the hub under a scope.

>
>
>>Is it that the spoke pairs are squeezed together only briefly? The
>>Brinell test usually presses a hardened ball into aluminum for 10-15
>>seconds, so maybe time is the answer?
>
>
> I don't believe so because the main effect on a hub is not time
> dependent nor is the yielding of high stress points on the
> spoke... not in the speed of the human hand, or Trek's press.

but there /is/ a time effect. that's why, as discussed elsewhere in
this thread, time is part of the brinel test spec, and why mechanical
stress relief needs to be undertaken shortly after initial deformation.

>
>
>>If there is further bedding in, would it necessarily be visible to
>>the naked eye? That is, the initial bedding in will be dramatic, a
>>smooth surface showing a faint dent, but after that, the faint dent
>>just gets a little deeper and wider, with the deformation being
>>spread out over a larger area. A Brinell test uses a microscope
>>with a measuring grid to detect differences in the size of the
>>deformation.
>
>
> Do some of your own testing if you are interested.

but you're the "expert". "experts" test & publish results. btw, what
is your spoke tension?

>
> [email protected]

 

[[email protected]]

On Sat, 25 Jun 2005 02:05:36 GMT,
[email protected] wrote:

>Carl Fogel writes:
>
>>> These elongations by yielding are in the micro-inches and have
>>> negligible effect on spoke length, and therefore, tension. That
>>> the spokes "bed in" is accomplished before this stage just by
>>> tension. Therefore there is no significant change in spoke support
>>> although some people believe that this is a major factor in stress
>>> relieving. To those who believe this, I suggest they spoke up a
>>> wheel with new hubs to full tension without stress relieving, and
>>> remove a spoke to see that it is fully bedded in.
>
>> How does the aluminum hub know to let spokes bed in when tensioned
>> to say 200 pounds, but not to let the spokes bed in any further when
>> pairs of spokes are squeezed together to raise (in theory) the
>> tension to roughly triple that amount and to bring (in theory)
>> stainless steel spokes to near yield?
>
>I think you are aware of asymptotes and bedding in is one of these
>effects that asymptotically ceases after a certain stress because the
>contact area becomes large enough that no more bedding in occurs. You
>can try this by spoking a wheel tightly and stress relieve a pair of
>spokes. You will not be able to detect on the hub which spokes you
>stress relieved when inspecting the spoke hole after spoke removal.
>
>> Is it that the spoke pairs are squeezed together only briefly? The
>> Brinell test usually presses a hardened ball into aluminum for 10-15
>> seconds, so maybe time is the answer?
>
>I don't believe so because the main effect on a hub is not time
>dependent nor is the yielding of high stress points on the
>spoke... not in the speed of the human hand, or Trek's press.
>
>> If there is further bedding in, would it necessarily be visible to
>> the naked eye? That is, the initial bedding in will be dramatic, a
>> smooth surface showing a faint dent, but after that, the faint dent
>> just gets a little deeper and wider, with the deformation being
>> spread out over a larger area. A Brinell test uses a microscope
>> with a measuring grid to detect differences in the size of the
>> deformation.
>
>Do some of your own testing if you are interested.
>
>[email protected]

Dear Jobst,

Hmmm . . .

It's curious that "after a certain stress" the bedding-in
always stops, no matter what the final spoke tension is, so
that no further effects can be observed from up pairs of
spokes being squeezed to produce (briefly) double or even
triple the final tension.

Possibly the bedding-in occurs at a very low tension, well
below normal spoke tension?

Carl Fogel

 

[41]

jim beam wrote:
> >> 41 wrote:

> >>>>>> if a component is not stress relieved shortly after initial
> >> >>>> formation, additional work can add to any existing residual
> >>>>>> stress, not
> >>>>>> mitigate it.

> >>>>> Specify deltaT. Specifiy the equation from which one calculates this
> >>>>> deltaT, or where it enters in any way. Specify the nature of the
> >>>>> "additional work", and the conditions that determine "will" and
> >>>>> "won't".
> >>>>>
> >>>>> I don't believe you can.


> as it happens, you all seem to have pretty much answered the question.
> dislocations tend to move around for a little while after they have been
> acivated.

Uh huh. Like I said...

 

[[email protected]]

On Fri, 24 Jun 2005 18:31:08 -0700, Benjamin Lewis
<[email protected]> wrote:

>[email protected] wrote:
>
>> The hard, round stainless steel spokes permanently deform the aluminum
>> hub when tensioned normally, but for some reason are not supposed to
>> produce any further deformation when a pair of them are squeezed to (in
>> theory) triple the tension and raise portion of the stainless steel to
>> yield.
>
>It doesn't triple the net spoke tension. It raises portions of the spoke,
>which are already at much higher tension than the rest of the spoke, to
>yield. This yield tension is on the order of 3 times higher than the
>net tension in the spoke before squeezing, but most of the spoke doesn't
>get to this tension.
>
>Roughly:
>
>
>3 ------ yield tension --------------------------------------
>
> /\
>2 / \ <--- point of high residual stress
> / \
> / \
>1 -----------------------/ \----
>
>
>0
>
>
>
>Squeezing the spoke brings the whole curve in this graph upwards; only the
>regions of high residual stress reach yield.
>
>Probably *some* bedding in occurs during the squeezing, but this doesn't
>change the gross picture.

Dear Benjamin,

I'm lost, but probably I just don't understand something
tricky about tension or am misunderstanding you.

When a pair of spokes at 200 pounds of tension are squeezed
together, I expect that the hub, the rim, and the spoke to
experience the same increase in tension--if it rises to 600
pounds anywhere, it rises to 600 pounds everywhere.

I think that I followed what Luns was saying and that you're
emphasizing here about only certain portions rising to from
a pre-stressed level to yield.

Why doesn't the entire spoke reach the same level of tension
if squeezed for several seconds? Am I mistaken or simply
misremembering previous estimates that the spoke tension
would double or even triple from around 200 pounds?

Would things change if a previously squeezed pair of spokes
were squeezed again?

I think that I'm asking about "net tension," but I'm not
even sure about that.

Thanks for your continuing efforts to get things through an
unusually thick head,

Carl Fogel

 

[jim beam]

[email protected] wrote:
> Dave vt? writes:
>
>
>>I understand everything you say, Benjamin. But what happens after
>>the spoke yields? If it yields, then the tension in that spoke must
>>be reduced, right? So now you bring the tension back up by turning
>>the nipple. How do you know that the stress in the spoke is not the
>>same as it was before stress relieving?
>
>
> If there were high stress locations, these would yield and when the
> overload is relaxed, stress cannot return to or close to the yield
> stress that existed locally from forming the spoke to it's current
> line.
>
> These elongations by yielding are in the micro-inches and have
> negligible effect on spoke length, and therefore, tension. That the
> spokes "bed in" is accomplished before this stage just by tension.
> Therefore there is no significant change in spoke support although
> some people believe that this is a major factor in stress relieving.
> To those who believe this, I suggest they spoke up a wheel with new
> hubs to full tension without stress relieving, and remove a spoke to
> see that it is fully bedded in.
>
> As I mentioned, stress in the elbow of a spoke supported in aluminum
> is lower than in the adjacent straight portion because the elbow is
> supported. It is like a winch. The cable does not snap on the
> winding spool but rather on a straight run where the cable pulls
> unaided.
>
>
>>I know I'm missing some simple, fundamental point. But I don't know
>>what it is.
>
>
> It is mainly a visualization of the magnitude of these changes. They
> are high stress and low elongation, steel being far stiffer than it
> appears from manual bending. The Modulus of elasticity expresses that
> the best.
>
> http://www.engineersedge.com/manufacturing_spec/properties_of_metals_strength.htm
>
>
>>There's another thing missing in this whole discussion, IMO. What
>>kind of stress are we talking about? Shear, longitudinal? Maybe
>>some combination of these, like the Von Mises stress? It's a bit
>>hard for me to imagine these residual stress profiles without that
>>bit of info.
>
>
> This is entirely reducible to tensile and compressive stress. As
> mentioned, the inside of a bend is compressed and the outside is
> stretched. That is the case with spoke elbows. It is primarily the
> residual tensile stresses that are interesting in this regard because
> they add to the stress of spoke tension, thereby being dangerously
> high for fatigue life.

but that's wrong. residual stress [if any] is /compressive/ on the
ouside of the spoke! doesn't that little sign change cause a problem
for your theory?

>
> Residual refers to stress that is not generated by tension in the
> spoke but localized stresses caused by manufacture and lacing the
> wheel, both of which plastically change (yield) the shape of the
> spoke.

manufacture & lacing can [but not always] yield the spoke, but residual
stress doesn't yield it.

> Whenever forming a wire with other than pure longitudinal
> tension, there will be residual tension and compression zones in that
> wire (spoke).

pure longitudinal tension causes tension AND compression jobst. ever
heard of poisson's ratio?

> The reason why pure tension on a wire does not cause
> residual stress

but pure tension /does/ cause residual stress, if not relieved.

> is that the entire cross section is subjected to
> uniform stress and when it is relaxed the entire cross section relaxes
> to zero, whether it reached yield or not. Every micro-inch of yield
> is "forgotten" by the spoke because it yielded and the road back is
> unrestricted.

it's not forgotten. dislocation theory jobst. you should check into it
some time. and "micro-inches" cause more residual stress than gross
yielding - dislocations have no long range order.

>
> [email protected]

 

[jim beam]

41 wrote:
>
> jim beam wrote:
>
>>>>41 wrote:
>
>
>>>>>>>>if a component is not stress relieved shortly after initial
>>>>>>>>formation, additional work can add to any existing residual
>>>>>>>>stress, not
>>>>>>>>mitigate it.
>
>
>>>>>>>Specify deltaT. Specifiy the equation from which one calculates this
>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
>>>>>>>"additional work", and the conditions that determine "will" and
>>>>>>>"won't".
>>>>>>>
>>>>>>>I don't believe you can.
>
>
>
>>as it happens, you all seem to have pretty much answered the question.
>>dislocations tend to move around for a little while after they have been
>>acivated.
>
>
> Uh huh. Like I said...
>
like you said what? you make cryptic sarcastic references, but you
don't state the question. is dislocation theory a problem for you?
spell your problem out. i'm not into guessing games.

 

[Benjamin Lewis]

[email protected] wrote:

> I'm lost, but probably I just don't understand something
> tricky about tension or am misunderstanding you.
>
> When a pair of spokes at 200 pounds of tension are squeezed
> together, I expect that the hub, the rim, and the spoke to
> experience the same increase in tension--if it rises to 600
> pounds anywhere, it rises to 600 pounds everywhere.

The point is that it doesn't *start* at 200 pounds (or whatever)
everywhere. It starts with most of the spoke at 200 pounds, and some small
portion (with residual stress) at 580 (or whatever) pounds. When you
squeeze the spokes together, you raise the tension everywhere by, say, 100
pounds, bringing the portion of the spoke with residual stress beyond
yield, but the rest staying well below.

--
Benjamin Lewis

"Love is a snowmobile racing across the tundra and then suddenly it flips
over, pinning you underneath. At night, the ice weasels come."
--Matt Groening

 

[41]

jim beam wrote:
> 41 wrote:
> > jim beam wrote:
> >>>>41 wrote:
> >>>>>>>>if a component is not stress relieved shortly after initial
> >>>>>>>>formation, additional work can add to any existing residual
> >>>>>>>>stress, not
> >>>>> >>>mitigate it.
> >
> >
> >>>>>>>Specify deltaT. Specifiy the equation from which one calculates this
> >>>>>>>deltaT, or where it enters in any way. Specify the nature of the
> >>>>>>>"additional work", and the conditions that determine "will" and
> >> >>>>>"won't".
> >>>>>>>
> >>>>>>>I don't believe you can.
> >
> >
> >
> >>as it happens, you all seem to have pretty much answered the question.
> >>dislocations tend to move around for a little while after they have been
> >>acivated.
> >
> >
> > Uh huh. Like I said...
> >
> like you said what? you make cryptic sarcastic references, but you
> don't state the question. is dislocation theory a problem for you?
> spell your problem out. i'm not into guessing games.

Like I said: I don't believe you can answer the questions. The
questions are stated perfectly clearly above, in my original post, and
if those questions are not perfectly clear to you, you don't have a
clue what you are talking about. Your dodges and evasions are also
perfectly clearly stated above, in your replies.

 

[jim beam]

41 wrote:
>
> jim beam wrote:
>
>>41 wrote:
>>
>>>jim beam wrote:
>>>
>>>>>>41 wrote:
>>>>>>
>>>>>>>>>>if a component is not stress relieved shortly after initial
>>>>>>>>>>formation, additional work can add to any existing residual
>>>>>>>>>>stress, not
>>>>>>>>>>mitigate it.
>>>
>>>
>>>>>>>>>Specify deltaT. Specifiy the equation from which one calculates this
>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
>>>>>>>>>"additional work", and the conditions that determine "will" and
>>>>>>>>>"won't".
>>>>>>>>>
>>>>>>>>>I don't believe you can.
>>>
>>>
>>>
>>>>as it happens, you all seem to have pretty much answered the question.
>>>>dislocations tend to move around for a little while after they have been
>>>>acivated.
>>>
>>>
>>>Uh huh. Like I said...
>>>
>>
>>like you said what? you make cryptic sarcastic references, but you
>>don't state the question. is dislocation theory a problem for you?
>>spell your problem out. i'm not into guessing games.
>
>
> Like I said: I don't believe you can answer the questions. The
> questions are stated perfectly clearly above, in my original post, and
> if those questions are not perfectly clear to you, you don't have a
> clue what you are talking about. Your dodges and evasions are also
> perfectly clearly stated above, in your replies.
>
habeus corpus.

 

[[email protected]]

On 24 Jun 2005 19:34:30 -0700, [email protected] wrote:

>Why not call Trek and ask to speak with the wheel engineers? You could
>ask them who developed the calculations for stressing the spokes and
>talk to that person.
>
>[email protected] wrote:
>> On Fri, 24 Jun 2005 08:34:25 GMT,
>> [email protected] wrote:
>>
>> >Carl Fogel writes:
>> >
>> >>> People who stress relieve don't see these occurrences and they have
>> >>> statistically significant samples, such as Trek bicycles.
>> >
>> >> Where can we find the details of Trek's statistically significant
>> >> sampling of stress relief effects on bicycle spokes?
>> >
>> >You probably can't, but in talking with their engineers their method
>> >of stress relieving was described and that they are satisfied with the
>> >results that reduced spoke failures to practically zero. Their
>> >process takes about 15 seconds per machine built wheel after the wheel
>> >comes out of final truing.
>> >
>> >[email protected]
>>
>> Dear Jobst,
>>
>> Darn! I was hoping for better than that. It sounded
>> promising.
>>
>> And if the spoke failures were already practically zero
>> beforehand . . .
>>
>> Carl Fogel

Dear Dianne,

Asking Trek about whatever Jobst is talking about sounds
like a sensible idea, but when I looked at:

http://www2.trekbikes.com/en/Bikes/Index.php

I found that most Trek road bikes use Bontrager wheels.

Some of the BMX bikes and mountain models showed that the
wheels came from "WTB" or simply listed them as "alloy" rims
and hubs.

Possibly Jobst can simplify things by telling us who the
Trek (or perhaps Bontrager) engineers were or emailing them
himself to get the details of conversations that only he
knows about.

Or maybe one of the local bike shop owners who posts here
and is also a Trek dealer might be able to track things
down? Of course, it's understandable if dealers decline to
pursue a topic that might inflame customers or doesn't
really interest them.

Nice to see you posting here again.

Carl Fogel

 

[[email protected]]

On Fri, 24 Jun 2005 21:47:15 -0700, Benjamin Lewis
<[email protected]> wrote:

>[email protected] wrote:
>
>> I'm lost, but probably I just don't understand something
>> tricky about tension or am misunderstanding you.
>>
>> When a pair of spokes at 200 pounds of tension are squeezed
>> together, I expect that the hub, the rim, and the spoke to
>> experience the same increase in tension--if it rises to 600
>> pounds anywhere, it rises to 600 pounds everywhere.
>
>The point is that it doesn't *start* at 200 pounds (or whatever)
>everywhere. It starts with most of the spoke at 200 pounds, and some small
>portion (with residual stress) at 580 (or whatever) pounds. When you
>squeeze the spokes together, you raise the tension everywhere by, say, 100
>pounds, bringing the portion of the spoke with residual stress beyond
>yield, but the rest staying well below.

Dear Benjamin,

D'oh!

I think that I see what you mean by net tension--overall
original spoke tension plus residual stress plus increased
tension, all moving toward yield?

But now I'm trying to add the numbers up and not getting to
where I think that expect me to arrive.

For simplicity, imagine that the straight spoke section
below is actually the curved elbow, with multiple residual
stress layers:

convex side, narrower stress, outside of elbow

-------c wide stress band ---
-------- neutral-------------
-------t wide stress band ---
-------- neutral--------
-------c narrow stress band--
-------- neutral-------------
-------t narrow stress band--

concave side, wider stress areas, inside of elbow

I'm basing this on the neutron diffraction picture in the
link that Peter Cole provided:

http://www.ncnr.nist.gov/AnnualReport/FY1999/residual.pdf

If I follow your idea, increasing the tension on the spoke
(already tightened to 200 pounds tension) by squeezing pairs
together might raise the general tension 100 pounds to a
general level of 300 pounds tension:

200 pounds general tension from tightening spokes
100 pounds more general tension from squeezing pairs
---
300 pounds general tension

This is still well below the roughly ~600 pound tension
needed to yield a 2 mm spoke generally.

But it would be enough to raise pre-existing residual stress
areas already at 300 pounds tension (when spokes are
tightened) to yield:

200 pounds general tension from tightening spokes
100 pounds more general tension from squeezing pairs
300 pounds local band of residual-stress tension
---
600 pounds tension at local band of residual-stress

Yield! Stress relieved!

But what happens to the local bands of residual stress that
were at less than 300 pounds of local tension? They didn't
reach yield, did they? Bands of local tension from 1 to 299
pounds wouldn't be affected.

And what happens to the bands of local compression? The
neutral bands would reach yield tension before the
compression bands would even go to neutral, much less to
yield tension, wouldn't they?

I end up with only the highest 100 pounds of residual
tension bands being yielded--this lowers the peak residual
tension from 300 pounds to 200 pounds and doesn't seem to
affect the residual compression bands at all.

I suspect that I'm closer to understanding the theory, but
still missing a crucial step or two.

How much does squeezing a pair of 290 mm spokes together at
the middle with 100 lbs force (reasonable grip) raise their
already 200 lb tension?

How high are the residual tensions and what's the yield
force?

That is, when would the extra tension plus the original
tension reach yield for a stainless steel 2 mm spoke?

Jobst's tensile tests at the end of the 2nd and 3rd edition
of "The Bicycle Wheel" show force in kg and strain in mm for
several spokes from 1988 and 1993, but I'm not sure where
yield would be on the smoothly curving slopes.

(I have no 1st edition, but page 132 of the 2nd edition says
that "In contrast to tests performed for the first edition
of this book, these spokes withstood substantial elongation
before failure.")

Do the 200/100/300/600 pound figures seem to be in the
ballpark? Would the highest residual tensions just drop from
a peak of 300 pounds to 200 pounds with a 100 pound squeeze?

And what am I missing about the residual compressions? Do
they vanish or not matter or what?

Sorry to be so lengthy, but I'm trying to work out what look
like promising details, and nobody can figure out what's
baffling me unless I scribble it out in detail.

Thanks again,

Carl Fogel

 

[41]

jim beam wrote:
> 41 wrote:
> >
> > jim beam wrote:
> >
> >>41 wrote:
> >>
> >>>jim beam wrote:
> >>>
> >>>>>>41 wrote:
> >>>>>>
> >>>>>>>>>>if a component is not stress relieved shortly after initial
> >>>>>>>>>>formation, additional work can add to any existing residual
> >>>>>>>>>>stress, not
> >>>>>>>>>>mitigate it.
> >>>
> >>>
> >>>>>>>>>Specify deltaT. Specifiy the equation from which one calculates this
> >>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
> >>>>>>>>>"addi tional work", and the conditions that determine "will" and
> >>>>>>>>>"won't".
> >>>>>>>>>
> >>>>>>>>>I don't believe you can.
> >>>
> >>>
> >>>
> >>>>as it happens, you all seem to have pretty much answered the question.
> >>>>dislocations tend to move a round for a little while after they have been
> >>>>acivated.
> >>>
> >>>
> >>>Uh huh. Like I said...
> >>>
> >>
> >>like you said what? you make cryptic sarcastic references, but you
> >>don't state the question. is dislocation theory a problem for you?
> >>spell your problem out. i'm not into guessing games.
> >
> >
> > Like I said: I don't believe you can answer the questions. The
> > questions are stated perfectly clearly above, in my original post, and
> > if those questions are not perfectly clear to you, you don't have a
> > clue what you are talking about. Your dodges and evasions are also
> > perfectly clearly stated above, in your replies.
> >
> habeus corpus.

HabeAs corpus.

Excusatio non petita, accusatio manifesta. Hic sepultus "jim beam",
requiescat in pace.e

 

[jim beam]

41 wrote:
>
> jim beam wrote:
>
>>41 wrote:
>>
>>>jim beam wrote:
>>>
>>>
>>>>41 wrote:
>>>>
>>>>
>>>>>jim beam wrote:
>>>>>
>>>>>
>>>>>>>>41 wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>>>>>if a component is not stress relieved shortly after initial
>>>>>>>>>>>>formation, additional work can add to any existing residual
>>>>>>>>>>>>stress, not
>>>>>>>>>>>>mitigate it.
>>>>>
>>>>>
>>>>>>>>>>>Specify deltaT. Specifiy the equation from which one calculates this
>>>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
>>>>>>>>>>>"addi tional work", and the conditions that determine "will" and
>>>>>>>>>>>"won't".
>>>>>>>>>>>
>>>>>>>>>>>I don't believe you can.
>>>>>
>>>>>
>>>>>
>>>>>>as it happens, you all seem to have pretty much answered the question.
>>>>>>dislocations tend to move a round for a little while after they have been
>>>>>>acivated.
>>>>>
>>>>>
>>>>>Uh huh. Like I said...
>>>>>
>>>>
>>>>like you said what? you make cryptic sarcastic references, but you
>>>>don't state the question. is dislocation theory a problem for you?
>>>>spell your problem out. i'm not into guessing games.
>>>
>>>
>>>Like I said: I don't believe you can answer the questions. The
>>>questions are stated perfectly clearly above, in my original post, and
>>>if those questions are not perfectly clear to you, you don't have a
>>>clue what you are talking about. Your dodges and evasions are also
>>>perfectly clearly stated above, in your replies.
>>>
>>
>>habeus corpus.
>
>
> HabeAs corpus.
>
> Excusatio non petita, accusatio manifesta. Hic sepultus "jim beam",
> requiescat in pace.e
>
what is your problem? if you disagree with my science, say so and
produce the corpse. all i see is personal dislike, which does not a
critic make.

 

[[email protected]]

Carl Fogel writes:
> Hmmm...

> It's curious that "after a certain stress" the bedding-in always
> stops, no matter what the final spoke tension is, so that no further
> effects can be observed from up pairs of spokes being squeezed to
> produce (briefly) double or even triple the final tension.

If this were not the case, spokes would rip out of the flange,
especially with stress relieving forces applied. Bedding in with
tensile tests that pulled spokes apart also stopped after the first
spoke was tested.

> Possibly the bedding-in occurs at a very low tension, well below
> normal spoke tension?

How about "normal tension" of about 180# force or thereabouts. As I
said, it's an asymptotic effect, meaning t isn't totally arrested but
effectively so because after the wire contour is conformal over more
than 1/3 its cross section, not much more occurs.

[email protected]

 

[41]

jim beam wrote:
> 41 wrote:
> >
> > jim beam wrote:
> >
> >>41 wrote:
> >>
> >>>jim beam wrote:
> >>>
> >>>
> >>>>41 wrote:
> >>>>
> >>>>
> >>>>>jim beam wrote:
> >>>>>
> >>>>>
> >>>>>>>>41 wrote:
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>>>>>if a component is not stress relieved shortly after initial
> >>>>>>>>>>>>formation, additional work can add to any existing residual
> >>>>>>>>>>>>stress, not
> >>>>>>>>>>>>mitigate it.
> >>>>>
> >>>>>
> >>>>>>>>>>>Specify deltaT. Specifiy the equation from which one calc ulates this
> >>>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
> >>>>>>>>>>>"addi tional work", and the conditions that determine "will" and
> >>>>>>>>>>>"won't".
> >>>>>>>>>>>
> >>>>>>>>>>>I don't believe you can.
> >>>>>
> >>> >>
> >>>>>
> >>>>>>as it happens, you all seem to have pretty much answered the question.
> >>>>>>dislocations tend to move a round for a little while after they have been
> >>>>>>acivated.
> >>>>>
> >>>>>
> >>>>>Uh huh. Like I said...
> >>>>>
> >>>>
> >> >>like you said what? you make cryptic sarcastic references, but you
> >>>>don't state the question. is dislocation theory a problem for you?
> >>>>spell your problem out. i'm not into guessing games.
> >>>
> >>>
> >>>Like I said: I don't believe you c an answer the questions. The
> >>>questions are stated perfectly clearly above, in my original post, and
> >>>if those questions are not perfectly clear to you, you don't have a
> >>>clue what you are talking about. Your dodges and evasions are also
> >>> perfectly clearly stated above, in your replies.
> >>>
> >>
> >>habeus corpus.
> >
> >
> > HabeAs corpus.
> >
> > Excusatio non petita, accusatio manifesta. Hic sepultus "jim beam",
> > requiescat in pace.e
> >
> what is your problem? if you disagree with my science, say so and
> produce the corpse. all i see is personal dislike, which does not a
> critic make.

It is you who has been called on to produce the corpse, since you are
the one laying the charges. The ever expanding length of the ">>>"
indicates the length of your dodging and evasions. Time to put up or
shut up:

> >>>>>>>>>>>>if a component is not stress relieved shortly after initial
> >>>>>>>>>>>>formation, additional work can add to any existing residual
> >>>>>>>>>>>>stress, not
> >>>>>>>>>>>>mitigate it.


> >>>>>>>>>>>Specify deltaT. Specifiy the equation from which one calc ulates this
> >>>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
> >>>>>>>>>>>"addi tional work", and the conditions that determine "will" and
> >>>>>>>>>>>"won't".
> >>>>>>>>>>>
> >>>>>>>>>>>I don't believe you can.`

 

[[email protected]]

Carl Fogel writes:

> Asking Trek about whatever Jobst is talking about sounds like a
> sensible idea, but when I looked at:

> http://www2.trekbikes.com/en/Bikes/Index.php

> I found that most Trek road bikes use Bontrager wheels.

Bontrager is a brand name of Trek and the wheels are built by Trek as
are their other wheels.

> Some of the BMX bikes and mountain models showed that the wheels
> came from "WTB" or simply listed them as "alloy" rims and hubs.

> Possibly Jobst can simplify things by telling us who the Trek (or
> perhaps Bontrager) engineers were or emailing them himself to get
> the details of conversations that only he knows about.

I think that Trek, like other manufacturers, is not interested in
engaging in sophistic skirmishes that this thread represents.

http://tinyurl.com/b79pw

[email protected]

 

[jim beam]

41 wrote:
>
> jim beam wrote:
>
>>41 wrote:
>>
>>>jim beam wrote:
>>>
>>>
>>>>41 wrote:
>>>>
>>>>
>>>>>jim beam wrote:
>>>>>
>>>>>
>>>>>
>>>>>>41 wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>jim beam wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>>>41 wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>>>>if a component is not stress relieved shortly after initial
>>>>>>>>>>>>>>formation, additional work can add to any existing residual
>>>>>>>>>>>>>>stress, not
>>>>>>>>>>>>>>mitigate it.
>>>>>>>
>>>>>>>
>>>>>>>>>>>>>Specify deltaT. Specifiy the equation from which one calc ulates this
>>>>>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
>>>>>>>>>>>>>"addi tional work", and the conditions that determine "will" and
>>>>>>>>>>>>>"won't".
>>>>>>>>>>>>>
>>>>>>>>>>>>>I don't believe you can.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>as it happens, you all seem to have pretty much answered the question.
>>>>>>>>dislocations tend to move a round for a little while after they have been
>>>>>>>>acivated.
>>>>>>>
>>>>>>>
>>>>>>>Uh huh. Like I said...
>>>>>>>
>>>>>>
>>>>>>like you said what? you make cryptic sarcastic references, but you
>>>>>>don't state the question. is dislocation theory a problem for you?
>>>>>>spell your problem out. i'm not into guessing games.
>>>>>
>>>>>
>>>>>Like I said: I don't believe you c an answer the questions. The
>>>>>questions are stated perfectly clearly above, in my original post, and
>>>>>if those questions are not perfectly clear to you, you don't have a
>>>>>clue what you are talking about. Your dodges and evasions are also
>>>>>perfectly clearly stated above, in your replies.
>>>>>
>>>>
>>>>habeus corpus.
>>>
>>>
>>>HabeAs corpus.
>>>
>>>Excusatio non petita, accusatio manifesta. Hic sepultus "jim beam",
>>>requiescat in pace.e
>>>
>>
>>what is your problem? if you disagree with my science, say so and
>>produce the corpse. all i see is personal dislike, which does not a
>>critic make.
>
>
> It is you who has been called on to produce the corpse, since you are
> the one laying the charges. The ever expanding length of the ">>>"
> indicates the length of your dodging and evasions. Time to put up or
> shut up:
>
>
>>>>>>>>>>>>>>if a component is not stress relieved shortly after initial
>>>>>>>>>>>>>>formation, additional work can add to any existing residual
>>>>>>>>>>>>>>stress, not
>>>>>>>>>>>>>>mitigate it.
>
>
>
>>>>>>>>>>>>>Specify deltaT. Specifiy the equation from which one calc ulates this
>>>>>>>>>>>>>deltaT, or where it enters in any way. Specify the nature of the
>>>>>>>>>>>>>"addi tional work", and the conditions that determine "will" and
>>>>>>>>>>>>>"won't".
>>>>>>>>>>>>>
>>>>>>>>>>>>>I don't believe you can.`
>
>
forgive me being distracted by your animosity - but perhaps that was
your intent. interesting also that you're not interested in relevant
answers from others.

time differences are typically from seconds to about a week. depends on
alloy system, solutes, interstitials, temperature, grain size,
dislocation density, etc. basically, the time taken to ship a spoke
from the manufacturer to a user is well outside the typical
inter-operation time in which mechanical stress relief can easily be
achieved.

 

[[email protected]]

On Sat, 25 Jun 2005 14:44:19 GMT,
[email protected] wrote:

>Carl Fogel writes:
>> Hmmm...
>
>> It's curious that "after a certain stress" the bedding-in always
>> stops, no matter what the final spoke tension is, so that no further
>> effects can be observed from up pairs of spokes being squeezed to
>> produce (briefly) double or even triple the final tension.
>
>If this were not the case, spokes would rip out of the flange,
>especially with stress relieving forces applied. Bedding in with
>tensile tests that pulled spokes apart also stopped after the first
>spoke was tested.
>
>> Possibly the bedding-in occurs at a very low tension, well below
>> normal spoke tension?
>
>How about "normal tension" of about 180# force or thereabouts. As I
>said, it's an asymptotic effect, meaning t isn't totally arrested but
>effectively so because after the wire contour is conformal over more
>than 1/3 its cross section, not much more occurs.
>
>[email protected]

Dear Jobst,

Well, how about it?

Was your "How about" an observation without a question mark,
reflecting actual figures? Or just speculation?

Are you saying that normal spoke tension for your wheels is
about 180 pounds? (People have asked without any response,
so I'm curious.)

And that this 180 pound tension just happens to be the point
at which about a dent about 1/3 of your spoke's cross
section has formed in your hub?

You used "cross-section," so I assume that's what you meant
instead of width.

If the same spoke tension buries a third of a 2 mm spoke
elbow's cross-section in the hub, shouldn't the same tension
bury a 1.8 mm spoke elbow more than a third of its cross
section?

A third of a 2 mm spoke's cross section amounts to 1.05
mm^2, while a third of a 1.8 mm spoke's cross section
amounts to 0.85 mm.

To displace the same 1.05 mm^2 of metal as 33.3% of the 2 mm
spoke, the 1.8 mm spoke has to force 41% of its cross
section into the hub.

More force drives the same Brinell ball deeper into the same
material.

With the same force, a smaller Brinell ball is driven deeper
into the same material and the dent shows more
cross-section.

The round dent's expansion does require markedly more force
as it widens, but why pick 1/3 cross-section as the
effective limit?

Is this a universal formula, or is it specific to steel
spokes and aluminum hubs, or is it even more specific to 2
mm spokes and not 1.8 mm spokes on a particular hub?

Carl Fogel

 

[[email protected]]

Carl Fogel writes:

>>> Hmmm...

>>> It's curious that "after a certain stress" the bedding-in always
>>> stops, no matter what the final spoke tension is, so that no
>>> further effects can be observed from up pairs of spokes being
>>> squeezed to produce (briefly) double or even triple the final
>>> tension.

>> If this were not the case, spokes would rip out of the flange,
>> especially with stress relieving forces applied. Bedding in with
>> tensile tests that pulled spokes apart also stopped after the first
>> spoke was tested.

>>> Possibly the bedding-in occurs at a very low tension, well below
>>> normal spoke tension?

>> How about "normal tension" of about 180# force or thereabouts. As
>> I said, it's an asymptotic effect, meaning t isn't totally arrested
>> but effectively so because after the wire contour is conformal over
>> more than 1/3 its cross section, not much more occurs.

> Well, how about it?

> Was your "How about" an observation without a question mark,
> reflecting actual figures? Or just speculation?

> Are you saying that normal spoke tension for your wheels is
> about 180 pounds? (People have asked without any response,
> so I'm curious.)

For a 36-spoke wheel, that's a reasonable tension. Mine lie between
that an 200 pounds.

> And that this 180 pound tension just happens to be the point at
> which about a dent about 1/3 of your spoke's cross section has
> formed in your hub?

As I mentioned, this is an asymptotic function that gets to
diminishing limits soon or you couldn't use aluminum for flanges in
which to anchor spokes. This is a metal, not a plastic.

> You used "cross-section," so I assume that's what you meant
> instead of width.

No. I meant cross section. Spokes are round in cross section and
when about 120 degrees of that make contact, bedding in becomes
limiting with a typical 3mm thick flange and conventional spokes.

> If the same spoke tension buries a third of a 2 mm spoke elbow's
> cross-section in the hub, shouldn't the same tension bury a 1.8 mm
> spoke elbow more than a third of its cross section?

If the moon is made of green cheese...

> A third of a 2 mm spoke's cross section amounts to 1.05 mm^2, while
> a third of a 1.8 mm spoke's cross section amounts to 0.85 mm.

> To displace the same 1.05 mm^2 of metal as 33.3% of the 2 mm spoke,
> the 1.8 mm spoke has to force 41% of its cross section into the hub.

> More force drives the same Brinell ball deeper into the same
> material.

You'll notice that Brinell is not a linear function and that it takes
substantially more force to double the indentation diameter after it
is deep enough to start up the side of the ball.

> With the same force, a smaller Brinell ball is driven deeper into
> the same material and the dent shows more cross-section.

Yes.. have you done this? If you have you probably wouldn't pursue
it in this manner.

> The round dent's expansion does require markedly more force as it
> widens, but why pick 1/3 cross-section as the effective limit?

Go look at your hubs and see for yourself. There are mechanical
realities and you should get in touch with them first hand instead of
posing endless rhetorical leading questions that imply a hidden
agenda.

> Is this a universal formula, or is it specific to steel spokes and
> aluminum hubs, or is it even more specific to 2 mm spokes and not
> 1.8 mm spokes on a particular hub?

Great! That's a classic of your style. Why don't you just say what
you mean and not ***** foot around with smartass questions!

[email protected]