Making spokes..

joff said:

Hello,
Could someone please give me some advise on bending the non nipple end
when making some spokes. I will be using 2mm stainless.
Should I heat the wire to red hot before bending?
Once bent should I anneal the wire? If so what is the process for this?
Once the wire is bent should the bends be case hardened?
Many thanks in advance for your advise..

I can't imagine making spokes would be cost-effective. Why do you want
to do this? I believe you can get spokes in any size.

I don't know for sure, but I don't think spokes are case hardened.

--
Tom Reingold
Noo Joizy

joff said:

Hello,
Could someone please give me some advise on bending the non nipple end
when making some spokes. I will be using 2mm stainless.
Should I heat the wire to red hot before bending?
Once bent should I anneal the wire? If so what is the process for this?
Once the wire is bent should the bends be case hardened?
Many thanks in advance for your advise..

I understand both the head and the bend are forged, swaged, whatever you
want to call it. Basically they're squashed in a giant press, which
gives the correct shape but also (by orienting the grain) makes the
spoke stronger and more resistant to fatigue. Not something you can
really repeat at home.

Tom Reingold said:

I can't imagine making spokes would be cost-effective. Why do
you want to do this? I believe you can get spokes in any size.

*Any* size?
http://www.pennyfarthingworldtour.com/05280001.jpg

James Thomson

Joff Slegs said:

Could someone please give me some advise on bending the non nipple
end when making some spokes. I will be using 2mm stainless. Should
I heat the wire to red hot before bending? Once bent should I
anneal the wire? If so what is the process for this? Once the wire
is bent should the bends be case hardened? Many thanks in advance
for your advise.

Don't do it. Making spokes is not a trivial process even though it
seems so simple on first inspection. Above all, the alloy is critical
because it must be ductile while being already highly strain hardened.
Unless you have access to spoke specific stainless wire, I don't think
you can make a reasonable spoke. Besides, since you are apparently
not familiar with spoke forming, I think you might start with visiting
such a manufacturer's process. Some of that is explained in the URL
below.

http://tinyurl.com/4l86q

Jobst Brandt
[email hidden]

joff said:

Hello,
Could someone please give me some advise on bending the non nipple end
when making some spokes. I will be using 2mm stainless.
Should I heat the wire to red hot before bending?
Once bent should I anneal the wire? If so what is the process for this?
Once the wire is bent should the bends be case hardened?
Many thanks in advance for your advise..

first, there's not a lot of point, really, using pre-made is a lot better.

if you really need to make some, you need to upset the head, then bend
the elbow using a mandrel. regarding threads, roll, don't cut them.

the biggest concern is the material you're using. you ask whether you
should heat and/or anneal. most spokes are made of a cold worked wire
whose strength derives from that work history. annealing would remove
that strength, so no, do not heat and/or anneal. you then ask about
case hardening. afaik, that's not something you can easily do with a
stainless wire. you can do it with carbon steels, but it's a tricky
process and not something you can generally do at home - especially if
you want to nitride. and again, i'm not sure of the benefit you're
seeking to achieve. case hardening is great in wear environments, and
can improve fatigue properties, but it's going to be real hard to form a
spoke to the shape you want, carburize or nitride, refinish [as the case
hardening will affect your original surface], then thread. you're much
better off using untreated spokes that are readily formable and make
sure that the original wire is of a suitable strength & fatigue grade
from the outset.

Give it a try.

1. Upset the head
2. Bend the elbow. See the dimensions at DT Swiss' web site:
http://www.dtswiss.com/index.asp?fuseaction=spokes.bikedetail&id=8 then
clock on the little icon of the T-square.
3. Cut to length and roll the threads. Use something like a Phill Wood
spoke machine. Some good bike shops have them. See
http://www.philwood.com/webcatolog/page20.htm

Usually no other structural processing is done. No anneal, no
hardening, etc.. From what I've seen, it's all done at room temperature
with precise but brute-force machines.

But Phill Wood may be willing to make spokes, maybe even extra long
ones... http://www.philwood.com/webcatolog/pg20.htm

Quoted message said:

Tom Reingold said:

I can't imagine making spokes would be cost-effective.

Why do

Quoted message said:

Quoted message said:

you want to do this? I believe you can get spokes in any size.

James Thomson said:

*Any* size?
http://www.pennyfarthingworldtour.com/05280001.jpg

Yep.

Those you get from Diane Blake:
[email hidden]

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Quoted message said:

Joff Slegs said:

Could someone please give me some advise on bending the non nipple
end when making some spokes. I will be using 2mm stainless. Should
I heat the wire to red hot before bending? Once bent should I
anneal the wire? If so what is the process for this? Once the wire
is bent should the bends be case hardened? Many thanks in advance
for your advise.

Don't do it. Making spokes is not a trivial process even though it
seems so simple on first inspection. Above all, the alloy is critical
because it must be ductile while being already highly strain hardened.
Unless you have access to spoke specific stainless wire, I don't think
you can make a reasonable spoke. Besides, since you are apparently
not familiar with spoke forming, I think you might start with visiting
such a manufacturer's process. Some of that is explained in the URL
below.

http://tinyurl.com/4l86q

Jobst Brandt
[email hidden]

when are you going to update your "faq" from that link? your metallurgy
is awful. your deformation theory is awful.

1. "Spokes are cold formed from wire that is (at least DT) as hard and
work hardened as it can become." not so. the ductility charts in the
back of your book prove that. if your test spokes were fully hard, the
plastic zone of your graphs would wholly fall, not rise.

2. "Tensioning does not further harden spokes, there being no plastic
deformation." except that you recommend "correcting the spoke line",
which of course does involve plastic deformation, and therefore work
hardening. in the context of your book using an illustration of mild
steel deformation, where yield can indeed occur without work hardening,
you seem somewhat uncertain about deformation theory here.

3. "Besides, wire ductility is important in both forming spokes and in
use." is in direct contradiction with statement 1.

4. "Reverse bending acts as a degausser." why would you want to try
demagnetizing an austenitic material?

5. "This stress relieves the wire while removing the curl of being
shipped in a coil." what on earth makes you think the objective is
stress relief??? - that operation is simply to straighten the wire so it
can be processed!

6. "after which the spoke is cut to a specific length before rolling the
thread and bending a 100 degree elbow." 90-95 degrees. see:
http://www.dtswiss.com/data/files/DAT_EN_30430224207.pdf

7. "Threads, head, and elbow, contain metal that was plastically
deformed (beyond yield) as well as metal that was elastically deformed,
each having elastic memory." what relevance is anything that "was"
plastically deformed??? either it currently is, or it isn't. so
therefore, how can both have "elastic memory"? presumably you mean that
some /is/ elastically deformed & thus has residual stress. but on what
level? do you have any evidence to support that a. this is the case, &
b. this is relevant in the context of an extensively cold worked
material having a very high dislocation density? dislocations, by their
very nature, are regions of very high lattice stress. it's the
interaction of their stress fields that gives cold worked material its
strength.

8. "In these transitions, parts that yielded and ones that did not
conflict, each wanting to return to or stay in a different shape. This
is why a spoke bent by hand springs back only partially when released."
no. it springs back in accordance with the hookes law part of the
graph, much as a hysteresis loop of a polymer extends on one line and
returns n another. unlike hysteresis however, a yielded metal's graph
remains permanently translated away from origin.

9. "On lacing spokes into a wheel, elbows are often additionally bent
(brought to yield), thus remaining at or exceeding yield stress during
tensioning." as recommended by you with "correcting the spoke line".
spoke manufacturers otoh specifically recommend against this practice,
presumably because of the introduction of residual stress.

10. "Threads also have internal tensile stress besides local compressive
stress at the threads." ok, so which is where? is tensile [if any] at
the root or the tip of the thread?

11. "The thread core is already in tension from the lengthening effect
of thread rolling and its stress only increases with tensioning." this
assumes rolling threads lengthens the spoke - cite your evidence.

12. "Therefore, spokes in a newly built wheel have locations where
stress is near yield, some more so than others." "near yield"??? cite
your research! you've never cited a number for what you believe this
residual stress to be. and again, on what level are you going to
differentiate from dislocation lattice stress?

13. "Because fatigue endurance of a metal at or near the yield stress is
short, cyclic loads in such spokes will cause failures at high stress
points." use of the word "endurance" implies a serious misconception -
that stainless spoke wire has an endurance limit. it doesn't.

14. "In normal use, a wheel only unloads spokes" that should read "in
pure radial load, the wheel only unloads spokes". lateral stresses
increase spoke load. lateral stresses are common.

15. "but with spokes near yield, even these stress cycles readily cause
fatigue failures." yes, that's why manufacturers have maximum tension
specs. unlike "as high as the rim will bear".

16. "Only the lightest riders on smooth roads might be spared failures
with a wheel whose spokes have not been stress relieved." again,
where's your evidence that there's residual stress? reliable wheels are
built with high quality spokes made of vacuum degassed fatigue resistant
wire with a high quality surface finish. otherwise you'd be able to
build fatigue proof wheels out of any old rubbish.

17. "Stress relieving to relax these high stress points is accomplished
by over-stressing them in order to erase their memory." first, you need
to address manufacturer is incompetence. second, it assumes you can
yield a typical 2.0/1.8/2.0 spoke [that requires about 3000N] by hand.

18. "It is not done to bed the spokes into the hub, as is often stated.
Bedding-in occurs sufficiently from tension." rubbish. build a new
wheel, true without "stress relief", then go ride around the block. it
will be completely untrue on your return because the hub holes, [& to a
lesser extent, the nipple/rim seat interface] have indeed seated in use.
the "stress relief" process as you call it achieves stability of
mechanical structure by accelerating this bedding in process. your
assumptions of improved metallurgical properties, based on the contents
of your book, are based on fundamental misconceptions.

19. "However, stretching spoke pairs with a strong grasp at midspan, can
momentarily increased tension by 50% to 100%. Because spokes are usually
tensioned no higher than 1/3 their yield stress, this operation has no
effect on the spoke as a whole, affecting only the small high stress
zones where spokes are near yield. By stretching them, these zones relax
below yield by as much as the overload." ok, so assuming we have an
incompetent manufacturer that produced residually stressed spokes,
you're again somehow managing to bypass hookes law by bringing stress
"below yield"? that requires explanation.

20. "Stress relieving with a light grasp of spoke pairs is worthless, as
is bouncing the wheel or bending it in a partially opened drawer.
Pressing axially on the hub, while supporting the rim, requires a force
larger than is manually possible but is effective for spoking machines
(except the left side rear spokes that would collapse the rim). Another
not recommend method, is laying the wheel on the floor and walking on it
with tennis shoes, carefully stepping on each pair of crossed spokes.
The method works but bends the rim and is difficult to control.

It is STRESS RELIEVING! Even though people insist on calling it
pre-stressing or seating-in. The wheel is already pre-stressed when
tensioned."

jobst, you can call it whatever you want as long as you want. fact is,
the process /does/ cause additional seating or bedding in, as described
in point 18 above. it /is/ an extremely important part of wheel
building, in existence long before you claim credit for its invention by
the way, but you really need to get off your high horse about pushing
the frontiers of materials science. but maybe you invented that too.

jim beam said:

...
2. "Tensioning does not further harden spokes, there being no plastic
deformation." except that you recommend "correcting the spoke line",
which of course does involve plastic deformation, and therefore work
hardening. in the context of your book using an illustration of mild
steel deformation, where yield can indeed occur without work hardening,
you seem somewhat uncertain about deformation theory here....

Are these plots of engineering-stress/engineering strain or
true-stress/true-strain? Of course, true-stress/true strain curves can
not be obtained beyond the point that necking occurs (which would be
typical of most steels).

--
Tom Sherman - Near Rock Island

On Wed, 29 Dec 2004 19:42:36 -0800, jim beam
<[email hidden]> wrote:

[snip]

Quoted message said:

4. "Reverse bending acts as a degausser." why would you want to try
demagnetizing an austenitic material?

[snip]

Dear Jim,

At the moment, I'm fussing with the history of Shakespeare's
editors, an argumentative crowd given to disagreeing
violently with each other about whether the text is genius
or a misprint.

(The printers back then couldn't spell words the same way
twice in a row or even number the pages consecutively, so
things are trickier than you'd think.)

Anyway, "degausser" does indeed seem strange.

After pondering the section in which that puzzling sentence
appears, I wondered if Jobst meant "de-stresser" instead of
"degausser" and merely plucked the wrong word off the shelf.

I also tried "de-gasser", but it's a bit late in the process
for that to make sense.

But it turns out that there is a perfectly good poetic
meaning of "degausser" in the sense of erasing a memory, in
this case a physical bend (to which the uncoiled wire would
remember to return) instead of the more prosaic magnetic
computer memory erased by whomping it with a degausser.

http://dictionary.reference.com/search?q=degausser

Lewis Theobald

Carl Fogel said:

Quoted message said:

4. "Reverse bending acts as a degausser." why would you want to
try demagnetizing an austenitic material?

Quoted message said:

At the moment, I'm fussing with the history of Shakespeare's
editors, an argumentative crowd given to disagreeing violently with
each other about whether the text is genius or a misprint.

Quoted message said:

(The printers back then couldn't spell words the same way twice in a
row or even number the pages consecutively, so things are trickier
than you'd think.)

Quoted message said:

Anyway, "degausser" does indeed seem strange.

Quoted message said:

After pondering the section in which that puzzling sentence appears,
I wondered if Jobst meant "de-stresser" instead of "degausser" and
merely plucked the wrong word off the shelf.

Quoted message said:

I also tried "de-gasser", but it's a bit late in the process for
that to make sense.

I suppose in the computer (CRT and storage medium) days, the basic
reduction in residual magnetization is no longer a common subject.
Typically a magnetized screwdriver cannot be demagnetized by
subjecting it to an opposite magnetic field to what it has, to drive
it to zero. It must be subjected to a alternating reversing field of
sufficient strength to magnetize over the existing polarity. This
field must then be diminished gradually to zero. This is usually done
by taking the screwdriver out of the reversing field while the field
remains at constant amplitude. In this way the magnetization is
continually reversed around ever decreasing hysteresis loops
approaching zero. There is no way of magnetically returning the
magnetized medium to zero in one step.

http://tinyurl.com/4m4r8
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/hyst.html

Similarly spoke wire can be "degaussed" stress relieved by running it
through zig-zag rollers of ever decreasing amplitude. One cannot do
this in one step except by a more cumbersome and non continuous method
of stretching the wire beyond yield. We do that after tensioning a
wheel.

Jobst Brandt
[email hidden]

Quoted message said:

Carl Fogel said:

Quoted message said:

4. "Reverse bending acts as a degausser." why would you want to
try demagnetizing an austenitic material?

Quoted message said:

At the moment, I'm fussing with the history of Shakespeare's
editors, an argumentative crowd given to disagreeing violently with
each other about whether the text is genius or a misprint.

Quoted message said:

(The printers back then couldn't spell words the same way twice in a
row or even number the pages consecutively, so things are trickier
than you'd think.)

Quoted message said:

Anyway, "degausser" does indeed seem strange.

Quoted message said:

After pondering the section in which that puzzling sentence appears,
I wondered if Jobst meant "de-stresser" instead of "degausser" and
merely plucked the wrong word off the shelf.

Quoted message said:

I also tried "de-gasser", but it's a bit late in the process for
that to make sense.

I suppose in the computer (CRT and storage medium) days, the basic
reduction in residual magnetization is no longer a common subject.
Typically a magnetized screwdriver cannot be demagnetized by
subjecting it to an opposite magnetic field to what it has, to drive
it to zero. It must be subjected to a alternating reversing field of
sufficient strength to magnetize over the existing polarity. This
field must then be diminished gradually to zero. This is usually done
by taking the screwdriver out of the reversing field while the field
remains at constant amplitude. In this way the magnetization is
continually reversed around ever decreasing hysteresis loops
approaching zero. There is no way of magnetically returning the
magnetized medium to zero in one step.

http://tinyurl.com/4m4r8
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/hyst.html

Similarly spoke wire can be "degaussed" stress relieved by running it
through zig-zag rollers of ever decreasing amplitude. One cannot do
this in one step except by a more cumbersome and non continuous method
of stretching the wire beyond yield. We do that after tensioning a
wheel.

Jobst Brandt
[email hidden]

so how exactly is that relevant for an austenitic steel? and more
importantly, how can you confuse ferromagnetism with residual stress?

Tom Sherman said:

jim beam said:

...
2. "Tensioning does not further harden spokes, there being no plastic
deformation." except that you recommend "correcting the spoke line",
which of course does involve plastic deformation, and therefore work
hardening. in the context of your book using an illustration of mild
steel deformation, where yield can indeed occur without work
hardening, you seem somewhat uncertain about deformation theory here....

Are these plots of engineering-stress/engineering strain or
true-stress/true-strain? Of course, true-stress/true strain curves can
not be obtained beyond the point that necking occurs (which would be
typical of most steels).

they're engineering. you can make reasonable true-stress/true-strain
graphs, but it does require a bit of sophistication. generally an
academic exercise.

Thanks for all the info chaps. I have made the spokes before by heating
the bends at the hub end. I have a thread roller and have never had a
spoke fail at the rim but quite a few at the hub. I have got round this
by using two normall spokes with a joining piece, (the second spoke cut
to length and a new thread rolled), but they don't look as good as a
single piece spoke.
As an aside, any idea who stocks a tap for cutting the 2mm spoke
thread? I have had no luck at all going through the normall channels,
DT and Sapim dont want to know?
Thanks, Joff

begin quoting James Thomson <[email hidden]>:

Quoted message said:

Tom Reingold said:

I can't imagine making spokes would be cost-effective. Why do
you want to do this? I believe you can get spokes in any size.

*Any* size?
http://www.pennyfarthingworldtour.com/05280001.jpg

There is nontrivial modern production of penny-farthings; they all get
spokes from somewhere and I don't believe they make 'em all by hand.
--
David Damerell <[email hidden]> Kill the tomato!

On Wed, 29 Dec 2004 21:38:24 +0100, "James Thomson" <[email hidden]>

Quoted message said:

Tom Reingold said:

I can't imagine making spokes would be cost-effective. Why do
you want to do this? I believe you can get spokes in any size.

*Any* size?
http://www.pennyfarthingworldtour.com/05280001.jpg

Sure. If you've got the tooling, the length of the spoke isn't that big a deal.
Well other than boring a hole in the floor under the press that's making the
head. 😉

Ron

joff said:

Thanks for all the info chaps. I have made the spokes before by heating
the bends at the hub end. I have a thread roller and have never had a
spoke fail at the rim but quite a few at the hub. I have got round this
by using two normall spokes with a joining piece, (the second spoke cut
to length and a new thread rolled), but they don't look as good as a
single piece spoke.
As an aside, any idea who stocks a tap for cutting the 2mm spoke
thread? I have had no luck at all going through the normall channels,
DT and Sapim dont want to know?
Thanks, Joff

taps cut. that'll give you significant fatigue problems. threads need
to be rolled.

http://www.biketoolsetc.com/index.cgi?id=848775844407&d=single&c=Tools&sc=Wheel%20and%20Rim&tc=Spoke%20Threading%20Machines&item_id=HZ-C700

"jim beam" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

jobst, you can call it whatever you want as long as you want. fact is,
the process /does/ cause additional seating or bedding in, as described
in point 18 above. it /is/ an extremely important part of wheel
building, in existence long before you claim credit for its invention by
the way, but you really need to get off your high horse about pushing
the frontiers of materials science. but maybe you invented that too.

It was very difficult for me to follow your arguments. Could you summarize?
Do you doubt:
1) that spokes have residual manufacturing stresses?
2) that these stresses result in premature fatigue failures?
3) that these stresses are non-uniform, and at some locations are near
yield?
4) that momentary 50% tension beyond max static (~1/3 yield) tension will
cause yield in those locations?

You seem fixated on dislocations/work hardening, I don't see the relevance.
The sources I've seen on residual stress indicate it can be separated into
3 kinds, those at the component, grain and atomic level, respectively.
Jobst is talking about the first category, you seem concerned about the
second.

This kind of stress relieving (mechanical vs. thermal) seems well known in
industry. Vibrational stress relief is commonly cited as an effective was
to eliminate residual manufacturing stresses. I think the comparison to
that technique is instructional.

Peter Cole said:

"jim beam" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

jobst, you can call it whatever you want as long as you want. fact is,
the process /does/ cause additional seating or bedding in, as described
in point 18 above. it /is/ an extremely important part of wheel
building, in existence long before you claim credit for its invention by
the way, but you really need to get off your high horse about pushing
the frontiers of materials science. but maybe you invented that too.

It was very difficult for me to follow your arguments. Could you summarize?
Do you doubt:
1) that spokes have residual manufacturing stresses?

yes, i doubt they have any of significance.

Quoted message said:

2) that these stresses result in premature fatigue failures?

if they exist or are introduced by "correcting the spoke line", sure
they can add to the fatigue equation, but factors of more significance
include quality of surface finish & inclusion content of the wire.

Quoted message said:

3) that these stresses are non-uniform, and at some locations are near
yield?

in general principle, residual stress can be non-uniform & can be near
yield, but there is no evidence presented on this forum, the "faq's" or
"the book" to support the contention that for spokes, the manufacturer
is incapable of addressing these issues before their product leaves the
factory. to claim that you can push back the frontiers of materials
science, make material mis-statements about deformation theory and take
credit for a the invention of a process that predates your birth does
nothing for the strength of that contention.

Quoted message said:

4) that momentary 50% tension beyond max static (~1/3 yield) tension will
cause yield in those locations?

if it exists, yes. but where's the beef? just because i read about
false brinelling in a text book doesn't mean that from that day forward,
every case of bearing race indentation i see is not true brinelling. if
one is going to claim that spokes have significant residual stress from
factory, bring out the stress corrosion testing, bring out the x-ray
measurements. /some/ evidence to support the claim.

Quoted message said:

You seem fixated on dislocations/work hardening, I don't see the relevance.
The sources I've seen on residual stress indicate it can be separated into
3 kinds, those at the component, grain and atomic level, respectively.
Jobst is talking about the first category, you seem concerned about the
second.

the relevance is that, in the absence of other defects, dislocation
density & the presence of slip bands materially effect fatigue
initiation & propagation. slip bands can be activated by increasing
dislocation density, ie. cold work. which is of course the result of
"correcting the spoke line". jobst's theory focuses on residual stress
as the fatigue initiator, somehow failing to acknowledge the importance
of design, material quality & surface finish. he then contends that
he's able to work the material in the strain aging deformation zone
illustrated in figure 15 of his book, without work hardening, without
reducing ductility in order to bring about relief. trouble is,
stainless steel spokes don't have that deformation characteristic!

Quoted message said:

This kind of stress relieving (mechanical vs. thermal) seems well known in
industry. Vibrational stress relief is commonly cited as an effective was
to eliminate residual manufacturing stresses. I think the comparison to
that technique is instructional.

mechanical relief for drawn wire is only really effective if
administered immediately after the process that introduced it. just
because a mechanical relief exists & is relevant in one situation does
not mean it's relevant in another, much as steps needed to mitigate
false brinelling don't have any relevance to the mitigation of true
brinelling.

again, i do not discount the relevance of the build technique called
"stress relief", but jobst's [lack of] understanding of deformation
theory and assumption of manufacturer incompetence beggars his ability
to explain his claims.