Spoke 'wind-up' question

Dan Daniel said:

Just curious- when you (well, when I, maybe not you) get that pinging
noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both?

Quoted message said:

I keep seeing people refer to the wheel's trueness changing after the
wind-up is released. Which makes me think that it is assumed that the
spoke is moving in the nipple, and the effective length of the
spoke/nipple has now changed.

Quoted message said:

Are there other factors than a new effective spoke/nipple length that
causes the trueness of the wheel to change? For example, maybe a spoke
gets seated on first riding if the build wasn't good, and it also gets
wind-up because the build wasn't good. And people mistake wind-up
pinging as the reason the wheel has changed trueness when it is really
from other things that are often accompanied by wind-up?

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

Unscrewed spokes alter alignment.

Jobst Brandt
[email hidden]

[email hidden] wrote in message ...

Quoted message said:

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

It is not better lubricated, it overcomes stiction, and if it was oiled it
would not overshoot. Of course the use of linseed oil overcomes this
problem completely. As the oil dries, it will hold the nipple so as it does
not unwind because the oil adheres the nipple to the spoke.

Trevor

ddandan-<< I, maybe not you) get that pinging
noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both? >><BR><BR>

The nipple is staying put, the windup in the spoke is unwinding and 'rubbin'
against the adjacent spoke . The 'noise' can also be the nipple rubbing in the
rim.

When the windup comes oiut, the tension lessens.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Trevor Jeffrey said:

Quoted message said:

It is the spoke turning in the threads. The larger contact
diameter of the nipple on the rim has more drag than the spoke in
the thread due to similar friction but at greatly different
diameters. As spoke load is reduced under riding load, the spoke
slips in its threads first and while turning, is better lubricated
than a static joint, thereby nearly completely un-twisting if not
over-shooting.

Quoted message said:

It is not better lubricated, it overcomes stiction, and if it was
oiled it would not overshoot. Of course the use of linseed oil
overcomes this problem completely. As the oil dries, it will hold
the nipple so as it does not unwind because the oil adheres the
nipple to the spoke.

Stop hypothesizing and get real. Oiled or not and with any lubricant
you can use, stiction remains in the spoke-nipple interface. Your
suggestion that linseed oil solves this problem is untrue and that
this oil will prevent the spoke from turning in the nipple when the
wheel is first ridden assumes that the oil has had time to harden
before the wheel was used. Even then, friction in the nipple to rim
interface is greater than linseed oil friction unless the oil is
completely hardened.

Where do you get this stuff anyway or do you compose it on the fly?

Jobst Brandt
[email hidden]

quote=''Dan Daniel said:

Just curious- when you (well, when I, maybe not you) get that pinging
noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both?

Quoted message said:

I keep seeing people refer to the wheel's trueness changing after the
wind-up is released. Which makes me think that it is assumed that the
spoke is moving in the nipple, and the effective length of the
spoke/nipple has now changed.

Quoted message said:

Are there other factors than a new effective spoke/nipple length that
causes the trueness of the wheel to change? For example, maybe a spoke
gets seated on first riding if the build wasn't good, and it also gets
wind-up because the build wasn't good. And people mistake wind-up
pinging as the reason the wheel has changed trueness when it is really
from other things that are often accompanied by wind-up?

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

Unscrewed spokes alter alignment.

Jobst Brandt
[email hidden][/QUOTE]

I want to be clear as to what you are saying.
When the spoke(s) untwist in the nipple, doesn't the nipple also need to rotate in the rim hole by close to the same amount?

daveornee said:

Quoted message said:

Dan Daniel said:

Just curious- when you (well, when I, maybe not you) get that

pinging

Quoted message said:

noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both?

Quoted message said:

I keep seeing people refer to the wheel's trueness changing after

the

Quoted message said:

wind-up is released. Which makes me think that it is assumed that

the

Quoted message said:

spoke is moving in the nipple, and the effective length of the
spoke/nipple has now changed.

Quoted message said:

Are there other factors than a new effective spoke/nipple length

that

Quoted message said:

causes the trueness of the wheel to change? For example, maybe a

spoke

Quoted message said:

gets seated on first riding if the build wasn't good, and it also

gets

Quoted message said:

wind-up because the build wasn't good. And people mistake wind-up
pinging as the reason the wheel has changed trueness when it is

really

Quoted message said:

from other things that are often accompanied by wind-up?

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

Unscrewed spokes alter alignment.

Jobst Brandt
[email hidden]

I want to be clear as to what you are saying.
When the spoke(s) untwist in the nipple, doesn't the nipple also need
to rotate in the rim hole by close to the same amount?

As I understand it from what he has written-

No, the motion is in the spoke/nipple connection. The friction
(stiction?) in this interface is less than in the nipple/rim
interface, so when the length-wise tension of the spoke is relaxed
under weight, the wind-up is released in the spoke/nipple interface
before there is a sufficient reduction in friction in the nipple/rim
interface for any movement to occur there.

daveornee said:

Quoted message said:

Dan Daniel said:

Just curious- when you (well, when I, maybe not you) get that

pinging

Quoted message said:

noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both?

Quoted message said:

I keep seeing people refer to the wheel's trueness changing after

the

Quoted message said:

wind-up is released. Which makes me think that it is assumed that

the

Quoted message said:

spoke is moving in the nipple, and the effective length of the
spoke/nipple has now changed.

Quoted message said:

Are there other factors than a new effective spoke/nipple length

that

Quoted message said:

causes the trueness of the wheel to change? For example, maybe a

spoke

Quoted message said:

gets seated on first riding if the build wasn't good, and it also

gets

Quoted message said:

wind-up because the build wasn't good. And people mistake wind-up
pinging as the reason the wheel has changed trueness when it is

really

Quoted message said:

from other things that are often accompanied by wind-up?

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

Unscrewed spokes alter alignment.

Jobst Brandt
[email hidden]

I want to be clear as to what you are saying.
When the spoke(s) untwist in the nipple, doesn't the nipple also need
to rotate in the rim hole by close to the same amount?

As I understand it from what he has written-

No, the motion is in the spoke/nipple connection. The friction
(stiction?) in this interface is less than in the nipple/rim
interface, so when the length-wise tension of the spoke is relaxed
under weight, the wind-up is released in the spoke/nipple interface
before there is a sufficient reduction in friction in the nipple/rim
interface for any movement to occur there.

daveornee said:

Quoted message said:

Dan Daniel said:

Just curious- when you (well, when I, maybe not you) get that

pinging

Quoted message said:

noise as wind-up is released, what exactly is going on? Is the spoke
moving while the nipple stays still? Or is the nipple moving in the
rim? Both?

Quoted message said:

I keep seeing people refer to the wheel's trueness changing after

the

Quoted message said:

wind-up is released. Which makes me think that it is assumed that

the

Quoted message said:

spoke is moving in the nipple, and the effective length of the
spoke/nipple has now changed.

Quoted message said:

Are there other factors than a new effective spoke/nipple length

that

Quoted message said:

causes the trueness of the wheel to change? For example, maybe a

spoke

Quoted message said:

gets seated on first riding if the build wasn't good, and it also

gets

Quoted message said:

wind-up because the build wasn't good. And people mistake wind-up
pinging as the reason the wheel has changed trueness when it is

really

Quoted message said:

from other things that are often accompanied by wind-up?

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

Unscrewed spokes alter alignment.

Jobst Brandt
[email hidden]

I want to be clear as to what you are saying.
When the spoke(s) untwist in the nipple, doesn't the nipple also need
to rotate in the rim hole by close to the same amount?

Dear Dave,

From what Jobst and others have posted, I think that the
spoke in question has been over-tightened and is twisted
like the stripes on a barber pole.

Shortly after you begin riding on such a twisted spoke, the
repeated rapid loss of tension as the spoke rolls under the
hub and takes the load leads to the spoke threads breaking
free of the friction inside the nipple and untwisting.

The nipple doesn't move. It remains fixed in place while the
spoke untwists and unscrews itself. The barber-pole stripes
on the spoke would now dive straight down. The torsion of
over-tightening is now relaxed.

The reason that the twisted spoke unscrews inside the nipple
instead of spinning the nipple itself is that the nipple has
a much larger diameter contact with the rim than the spoke
has with the nipple threads.

Here's the situation in reverse. Take a toilet plunger with
a wooden handle threaded into rubber plunger and lean on it
with all your weight, pressing it onto a rubber mat. Now,
while still pressing on it, turn the wooden handle. The wide
rubber cup stays in place and the narrow wooden handle will
start to unthread.

Carl Fogel

Trevor Jeffrey said:

[email hidden] wrote in message ...

Quoted message said:

It is the spoke turning in the threads. The larger contact diameter
of the nipple on the rim has more drag than the spoke in the thread
due to similar friction but at greatly different diameters. As spoke
load is reduced under riding load, the spoke slips in its threads
first and while turning, is better lubricated than a static
joint, thereby nearly completely un-twisting if not over-shooting.

It is not better lubricated, it overcomes stiction, and if it was oiled it
would not overshoot. Of course the use of linseed oil overcomes this
problem completely. As the oil dries, it will hold the nipple so as it does
not unwind because the oil adheres the nipple to the spoke.

Why not use steel hubs, nipples and rims? Then everything could be
welded together after assembly. 😉

--
Tom Sherman – Quad City Area

Carl Fogel said:

Quoted message said:

I want to be clear as to what you are saying. When the spoke(s)
untwist in the nipple, doesn't the nipple also need to rotate in
the rim hole by close to the same amount?

Quoted message said:

From what Jobst and others have posted, I think that the spoke in
question has been over-tightened and is twisted like the stripes on
a barber pole.

Not so. Spokes, other than 1.5mm diameter, twist between 1/8 and 1/4
turn when tightened so that if the last adjustment is a tightening
one, the spoke has such a twist (when tightened to ideal tension).
This is the main reason machine built wheels are often too loosely
spoked, because final adjustment only twist the spoke with no change
in thread engagement. Therefore, there is no adjustment made and the
machine keeps repeating itself as it goes around because the next
attempt overcomes stiction and results in twice the amount of
adjustment required. Then the process repeats after backing off in a
similar manner.

Quoted message said:

Shortly after you begin riding on such a twisted spoke, the repeated
rapid loss of tension as the spoke rolls under the hub and takes the
load leads to the spoke threads breaking free of the friction inside
the nipple and untwisting.

The first time such a wheel is loaded spokes advance or back off in
their threads. As I explained, the nipple contact radius being
several times that of the spoke but with the same or worse friction,
only the thread changes position as spoke tension is reduced by
loading. Sometimes this occurs only when leaning the bicycle because
this causes a greater reduction in tension than the upright position.

Quoted message said:

The nipple doesn't move. It remains fixed in place while the spoke
untwists and unscrews itself. The barber-pole stripes on the spoke
would now dive straight down. The torsion of over-tightening is now
relaxed.

Well... that's a little exaggerated. The stripe has at best a quarter
turn helix, something that is hard to see no matter how you look at
it. Barber poles usually have a full turn:

http://www.adsd.com/holtz/bpole.html

Quoted message said:

The reason that the twisted spoke unscrews inside the nipple instead
of spinning the nipple itself is that the nipple has a much larger
diameter contact with the rim than the spoke has with the nipple
threads.

Quoted message said:

Here's the situation in reverse. Take a toilet plunger with a wooden
handle threaded into rubber plunger and lean on it with all your
weight, pressing it onto a rubber mat. Now, while still pressing on
it, turn the wooden handle. The wide rubber cup stays in place and
the narrow wooden handle will start to unthread.

What is more telling is that an unlubricated spoke nipple will rotate
so poorly in a rim that its flanks can be rounded by a spoke wrench.
In fact the spoke wrenches that engage four corners of the nipple are
unnecessary if the nipple contact in the rim is oiled, thereby
allowing the use of a parallel slot wrench to do the job and faster
than one that must be axially engaged.

Jobst Brandt
[email hidden]

Tom Sherman wrote in message <[email hidden]>...

Quoted message said:

Why not use steel hubs, nipples and rims? Then everything could be
welded together after assembly. 😉

Steel nipples could be tigged to spokes in short time. May be inappropriate
for team use, because tyres would have to be removed to replace a broken
spoke.

Trevor

[email hidden] wrote in message
<[email hidden]>...

Quoted message said:

What is more telling is that an unlubricated spoke nipple will rotate
so poorly in a rim that its flanks can be rounded by a spoke wrench.
In fact the spoke wrenches that engage four corners of the nipple are
unnecessary if the nipple contact in the rim is oiled, thereby
allowing the use of a parallel slot wrench to do the job and faster
than one that must be axially engaged.

Dear Jobst,
I sit with my jaw dropped. Are you advocating that oil is good for nipples?
Really?

Trevor

Trevor Jeffrey said:

Tom Sherman wrote in message <[email hidden]>...

Quoted message said:

Why not use steel hubs, nipples and rims? Then everything could be
welded together after assembly. 😉

Steel nipples could be tigged to spokes in short time.

You could also just use pliers to crimp the nipples onto the spokes if
for some reason you wanted to stop any adjustments/changes.

JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
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Trevor Jeffrey said:

[email hidden] wrote in message
<[email hidden]>...

Quoted message said:

What is more telling is that an unlubricated spoke nipple will rotate
so poorly in a rim that its flanks can be rounded by a spoke wrench.
In fact the spoke wrenches that engage four corners of the nipple are
unnecessary if the nipple contact in the rim is oiled, thereby
allowing the use of a parallel slot wrench to do the job and faster
than one that must be axially engaged.

Dear Jobst,
I sit with my jaw dropped. Are you advocating that oil is good for nipples?
Really?

Trevor

Dear Trevor,

Why, yes, it's a common practice to oil spoke threads (and
numerous other threaded fasteners) before assembly.

Among other advantages, lubrication makes it possible to
adjust extremely small nipples under high tension.
Otherwise, the wheel builder is likely to round off the
flats.

Once spoke twist (or wind-up) is eliminated, the tremendous
tension keeps the lubricated spoke nipples firmly in place,
despite the fears of laymen like me. There really isn't any
force acting to twist a straight, untwisted spoke or its
nipple.

I'm afraid that most of the dangling mandibles will be in
regard to anyone unfamiliar with this widespread technique.

Jobst, for example, explains oiling the spoke threads in his
book and even includes an oil can in the drawing of the
parts and tools needed to build a wheel.

Carl Fogel

John Forrest Tomlinson wrote in message ...

Quoted message said:

You could also just use pliers to crimp the nipples onto the spokes if
for some reason you wanted to stop any adjustments/changes.

No the nipples may split.

Trevor

Trevor Jeffrey said:

Quoted message said:

What is more telling is that an unlubricated spoke nipple will rotate
so poorly in a rim that its flanks can be rounded by a spoke wrench.
In fact the spoke wrenches that engage four corners of the nipple are
unnecessary if the nipple contact in the rim is oiled, thereby
allowing the use of a parallel slot wrench to do the job and faster
than one that must be axially engaged.

Quoted message said:

I sit with my jaw dropped. Are you advocating that oil is good for
nipples? Really?

I can't tell whether this is a facetious question or not, but since I
have not see much dry humor in your protestations, I'll assume it is
serious.

Yes, really, and the book you complain about so bitterly, outlines what
needs to be oiled to build good wheels. Why do you think oiling spoke
nipples is astonishing (jaw dropping)?

Jobst Brandt
[email hidden]

[email hidden] wrote in message ...

Quoted message said:

Why, yes, it's a common practice to oil spoke threads (and
numerous other threaded fasteners) before assembly.

Among other advantages, lubrication makes it possible to
adjust extremely small nipples under high tension.
Otherwise, the wheel builder is likely to round off the
flats.

Once spoke twist (or wind-up) is eliminated, the tremendous
tension keeps the lubricated spoke nipples firmly in place,
despite the fears of laymen like me. There really isn't any
force acting to twist a straight, untwisted spoke or its
nipple.

I'm afraid that most of the dangling mandibles will be in
regard to anyone unfamiliar with this widespread technique.

Jobst, for example, explains oiling the spoke threads in his
book and even includes an oil can in the drawing of the
parts and tools needed to build a wheel.

I am well aware of the requirement to use lubrication on a threaded
fastening, I cannot recall that Jobst called for this in his book. The
criticism I get for oiling the spoke threads with linseed comes from his
supporters. It has been put forward by these know it alls as a worthless
exercise because I do not adhere to spokes hanging or standing. To form and
voice an alternative opinion under the constant scything which I receive is
not easy. I may just get bored with it all and leave you in beautiful
Jobst world where everything is fine and dandy if you stress relieve your
spokes.

Trevor

Carl Fogel said:

Quoted message said:

Quoted message said:

What is more telling is that an unlubricated spoke nipple will
rotate so poorly in a rim that its flanks can be rounded by a
spoke wrench. In fact the spoke wrenches that engage four corners
of the nipple are unnecessary if the nipple contact in the rim is
oiled, thereby allowing the use of a parallel slot wrench to do
the job and faster than one that must be axially engaged.

Quoted message said:

Quoted message said:

I sit with my jaw dropped. Are you advocating that oil is good for
nipples? Really?

Quoted message said:

Why, yes, it's a common practice to oil spoke threads (and numerous
other threaded fasteners) before assembly.

Quoted message said:

Among other advantages, lubrication makes it possible to adjust
extremely small nipples under high tension. Otherwise, the wheel
builder is likely to round off the flats.

Quoted message said:

Once spoke twist (or wind-up) is eliminated, the tremendous tension
keeps the lubricated spoke nipples firmly in place, despite the
fears of laymen like me. There really isn't any force acting to
twist a straight, untwisted spoke or its nipple.

There really is a force although too small to overcome stiction of a
static thread that is as heavily loaded as this one. The ramp of a
spoke thread has a torque proportional to the slope and axial load and
is apparent on ball-screws that are made to have feedback to the
actuator that turns them. A ball screw nut will spin to the bottom
freely if the screw is held vertically. A free spoke nipple will not
turn when the spoke is held vertically.

Quoted message said:

I'm afraid that most of the dangling mandibles will be in regard to
anyone unfamiliar with this widespread technique.

Quoted message said:

Jobst, for example, explains oiling the spoke threads in his book
and even includes an oil can in the drawing of the parts and tools
needed to build a wheel.

I think Trevor is questioning the lubrication of the spoke nipple to
rim socket interface. This is where the main torque of spoke
adjustment arises and causes people to round off the flats on spoke
nipples.

Jobst Brandt
[email hidden]

Quoted message said:

Carl Fogel said:

Quoted message said:

> What is more telling is that an unlubricated spoke nipple will
> rotate so poorly in a rim that its flanks can be rounded by a
> spoke wrench. In fact the spoke wrenches that engage four corners
> of the nipple are unnecessary if the nipple contact in the rim is
> oiled, thereby allowing the use of a parallel slot wrench to do
> the job and faster than one that must be axially engaged.

Quoted message said:

Quoted message said:

I sit with my jaw dropped. Are you advocating that oil is good for
nipples? Really?

Quoted message said:

Why, yes, it's a common practice to oil spoke threads (and numerous
other threaded fasteners) before assembly.

Quoted message said:

Among other advantages, lubrication makes it possible to adjust
extremely small nipples under high tension. Otherwise, the wheel
builder is likely to round off the flats.

Quoted message said:

Once spoke twist (or wind-up) is eliminated, the tremendous tension
keeps the lubricated spoke nipples firmly in place, despite the
fears of laymen like me. There really isn't any force acting to
twist a straight, untwisted spoke or its nipple.

There really is a force although too small to overcome stiction of a
static thread that is as heavily loaded as this one. The ramp of a
spoke thread has a torque proportional to the slope and axial load and
is apparent on ball-screws that are made to have feedback to the
actuator that turns them. A ball screw nut will spin to the bottom
freely if the screw is held vertically. A free spoke nipple will not
turn when the spoke is held vertically.

Quoted message said:

I'm afraid that most of the dangling mandibles will be in regard to
anyone unfamiliar with this widespread technique.

Quoted message said:

Jobst, for example, explains oiling the spoke threads in his book
and even includes an oil can in the drawing of the parts and tools
needed to build a wheel.

I think Trevor is questioning the lubrication of the spoke nipple to
rim socket interface. This is where the main torque of spoke
adjustment arises and causes people to round off the flats on spoke
nipples.

Jobst Brandt
[email hidden]

Dear Jobst,

You're dead right about the slight force on the spiral ramp
of the threads, which I dismissed.

And you may be right, too, about which particular points of
lubrication startle Trevor, but I'm just guessing about the
source of his surprise.

In any case, I mentioned oiling only the threads of the
spokes and neglected the part where the nipple meets the
rim. Since you invariably mention both places when
describing wheel building, that was sloppy of me, so sorry
about that.

Carl Fogel