Tying and soldering explained 1898

"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
wrote:
On Sun, 04 Nov 2007 05:43:16 -0800, jim beam
wrote:

[snip]

There's no mention at all of tying to restrain
broken spokes, a common
explanation in RBT threads on the matter--and the
notion of a "hub" as
big as a circle drawn around the crossings is a new
notion to me.
(I should add that it's pretty much all wishful
thinking, as far as I
can tell. Jobst's tests showed no lateral strength
increase,
do they? he describes his test process, then his
conclusions. he doesn't present actual data or
analyze it - he simply dismisses differences he
confesses to measuring as "noise".

Dear Jim,

Yes, that's exactly what Jobst's testing showed--no
lateral (or
torsional, which I carelessly forgot) strength increase.

Here's his admirably detailed actual data, which
clearly supports his
analysis and conclusion, since the measured changes in
rim deflection
due to tying and soldering with practical loads were
less than the
variation of an extremely accurate dial gauge:

"Tying and Soldering"

"A small- and large-flange rear wheel were each tested
for lateral and
torsional elasticity. The hub of the wheel being
tested was securely
held in a machine tool vise by means of a modified
freewheel core. A
dial gauge was mounted on the machine table to observe
displacements.
Lateral deflection caused by a 160 N vertical force
applied repeatedly
at four different locations remained unchanged within
0.05 mm before
and after tying the spokes. The same arrangement was
used to measure
torsional deflection."

"For the torsional test a steel cable was wrapped
around the rim and
anchored to the valve stem hole. A pull of 300 N on
the wire produced
a rotational movement of 1.65 mm on a large-flange
wheel with 36
swaged spokes, and 3.43 mm on a similar small-flange
wheel. The
measurements were repeated several times and averaged,
both before and
after tying. The results in each case showed a change
of about 2%.
This was also the variance of the measurements that
were averaged. For
the small-flange wheel the deflection decreased when
tied, and for the
large-flange wheel it increased. It is apparent from
these results
that tying and soldering of spokes has so little
effect - if any -
that it is difficult to detect even by precision
measurement."

but that's not data, merely what he says is the
result. and presumptive conclusion. if he wanted to
be serious and credible, he'd include his data table so
the reader can judge for themselves.

and 300N pure torque is unrealistic. the true test is
torque + lateral loading, just like you'd get on a hill
when honking....

Er "jim", torque is force times the moment arm it acts
through. "300N" is a measure of force, not torque. The
correct SI unit for torque is "N-m" or "newton-meter".

you don't say. so, let me correct just to keep you from
****ing and moaning further:
"and 300N applied as pure torque loading is unrealistic."

but you knew that anyway.

Yes, it is unrealistic, since a newton is a force (or a
cookie) and not a torque. By the way, what is "impure
torque", the existence of which is implied by the term
"pure torque"?

eh? the force is applied in an orientation whereby the
wheel experiences pure torque loading.

Eh? What is "pure torque"? Do you mean "the only loading on
the wheel is a torque"?

If Jobst has a mass of 90kg, stands on a 0.18m long crank,
and applies some additional force by pulling on the
handlebars, a torque of 180 N-m at the crank is not
unreasonable. Using a 50% reduction (about the lowest gear
on Jobst's bicycle), we end up (ignoring drive-train
losses, which are small) with 90 N-m at the rear wheel, or
about what Jobst used in his test. Unrealistic, eh?

and the orientation is unrealistic. a wheel does not
experience pure torque loading.

How is the orientation unrealistic? Do you actually mean
that there should be other loads applied to this wheel
during the test?

of course! oh, wait, you only ride 'bents, so you can't
stand on the pedals...

Actually I have a Trek 6000, but do not ride it much since it
is not very comfortable and there are no good trails nearby.

Secondly, recumbents still put gravity loads on the wheels.

Thirdly, I expect I can put much HIGHER lateral loads on the
wheels of my recumbent trike than "jim beam" can on any of his
bicycles.

eh? how are you going to do that if you don't stand and lean
the "bike"?

It is called "turning, "jim". Centripetal force, you know.

and rotation produces lateral loads????? dude, you're _badly_
confused!!!

As in making a turn with the vehicle - duh! Note that I never used
the word "rotation".

but turning on a bike, unless you have a "safety" and are
jockeying, means the wheels continue to bear load radially, not
laterally. only on a trike will you get lateral loads.

Exactly my point! Yes, I can produce significant lateral loadings on
the wheels of my trike.

Since Jobst Brandt applied a 300N FORCE to the valve hole,

no, he applied it to a cable that was wrapped around the
rim and /anchored/ at the valve hole. force is actually
imparted by circumferential friction.

Is it? What if the wheel had a smooth rim strip, slightly
contaminated with lubricant? How much of force end up
being transmitted to the anchor at the valve hole?

if we assume an ISO 622-mm wheel, the resulting TORQUE
would have been approximately 90 to 95 N-m.

HTH,


it would help if you paid better attention to detail
where it mattered, and didn't **** and moan where it didn't.

Confusing the units of force and torque is NOT a small
matter.


don't put false words in my mouth.

I thought it was your keyboard (sans capital letters), not
your mouth.

lightweight.

Ooooooooh! An insult!

Eh "jim", you wrote "300N pure torque". Since when has the
newton (N) been a unit of torque instead of force?


go ahead and misconstrue! lightweight.

Kentucky Bourbon man still thinks that the newton is a unit of
torque, not force, and expects us to take him seriously. This
is high school level physics, even in dumbed down US public
schools.

I still want to know how the purity level of torque is
determined.


go ahead and misconstrue. lightweight.

We have established that "jim beam" believes the newton to be a
unit of torque!


no, you're putting false words in my mouth. again. perhaps if
you weren't such a lightweight...

No "jim", EVERYONE CAN READ WHAT YOU WROTE. Why not admit to a
typographical error and be done with it? Or is "jim beam" not
aware of how the English language works?


now you're being stupid. jobst's loading produces "pure torque".
if you want to argue it doesn't, you go right ahead. but don't
argue that what i said is hard to understand, and /definitely/
don't put false words in my mouth about units. that's bull**** and
you know it.

Here is proof I am not putting words into "jim beam's" mouth:
http://groups.google.com/group/rec.bicycles.tech/msg/df61fa7fce144bc4?dmode=source.
Next to last paragraph "jim beam" wrote "and 300N pure torque is
unrealistic".

Will "jim beam" now accuse Google of altering his posts?

no - i'm saying you don't understand plain english!

What is so hard to understand in the phrase "and 300N pure torque is
unrealistic"? To anyone that comprehends the English language, that is
saying the newton is a unit of torque, which is obviously wrong.

The SI unit of torque is the newton-meter, not the newton. See he
http://physics.nist.gov/cuu/Units/units.html - the newton (N) is a
unit of FORCE.

no ****.

Then why did you use the newton as a unit of torque, "jim"?

Being stupid is contiuning to claim that "300N" is a measurement of
torque, not force.

i'm not!!! /you/ are!

No "jim" is just being delusional.

If you meant to write "and 300N-m pure torque is unrealistic"
instead of "and 300N pure torque is unrealistic" just say so! Sheesh!

but there is 300N linear force applied in a pure torque-producing
orientation!!! - it's the orientation i'm addressing!

Then why the hell did you not say so in the first place?

i did to non-esl lay persons. [that doesn't include persons named "tom"
or "sherman" obviously.]

You mean lay persons that do not know the difference between a newton
and a newton-meter, and can be easily impressed by jargon?

jeepers tom, i started calling you a lightweight for being evasive.
now, i wonder about it as a deeper problem.

The sock puppet that will not post a single correction to clarify what
he/she actually meant to say is the one with the problem.


why the **** should i when you're the one getting it all wrong?
goddamned lightweight.

Why can you not admit you made a simple error, that you would have
caught if you had proofread your post more carefully?

--
Tom Sherman - Holstein-Friesland Bovinia
Tradition is the worst rational for action.

Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Joe Riel wrote:
jim beam writes:

and rotation produces lateral loads????? dude, you're _badly_
confused!!!

It's a recumbent trike. It doesn't lean when cornering, so the
wheels are subjected to lateral forces.

EXACTLY! The only lean (relative to the road surface) that occurs
when turning on my TRIKE is from the greater deflection of the
outside front tire, which is small enough to have no practical
significance.

i thought it was a bike, not trike. that's what i think he
showed with a green fairing recently.

This
http://www.ransbikes.com/Gallery/Archive/images/Sherman1.jpg is
NOT the only HPV (hominid powered vehicle) I own.

that is a BIke is it not?

By definition yes.

This is my Earth Cycles Dragonflyer TRIKE:
http://www.flickr.com/photos/19704682@N08/1939606083/. When
cornering hard, there is enough deflection to cause the front
brakes to rub very slightly, producing a cool ringing sound.


how inefficient.

Wrong. Yet another "expert" with no clue.


brake contact when you want it is fine. brake contact just because
you happen to be deviating from a straight line is not. lightweight.

If the brake contact is minimal, the efficiency loss is also minimal.
Duh!


eh? so by that rationale, it's ok if my inner tubes leak a little bit
when i corner?

But they do! Just not enough to matter in practical terms.

not as a function of cornering they don't!



Can "jim" find the proper analogy here?

how about if my chain skips 1 tooth in 100?

How about if your chain skips 1 tooth in 1,000,000? Is that a problem?
What about skipping 1 tooth in 1,000,000,000,000,000? Is that a problem?

you're just bull****ting to "defend" a dumb 'bent design.

I am not a bull, so "jim's" contention is a practical impossibility.


geeze, that's weak. quit the ****ing and moaning and stick to the tech
facts. if you can.

"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Joe Riel wrote:
jim beam writes:

and rotation produces lateral loads????? dude, you're
_badly_ confused!!!

It's a recumbent trike. It doesn't lean when cornering, so the
wheels are subjected to lateral forces.

EXACTLY! The only lean (relative to the road surface) that
occurs when turning on my TRIKE is from the greater deflection
of the outside front tire, which is small enough to have no
practical significance.

i thought it was a bike, not trike. that's what i think he
showed with a green fairing recently.

This
http://www.ransbikes.com/Gallery/Archive/images/Sherman1.jpg
is NOT the only HPV (hominid powered vehicle) I own.

that is a BIke is it not?

By definition yes.

This is my Earth Cycles Dragonflyer TRIKE:
http://www.flickr.com/photos/19704682@N08/1939606083/. When
cornering hard, there is enough deflection to cause the front
brakes to rub very slightly, producing a cool ringing sound.


how inefficient.

Wrong. Yet another "expert" with no clue.


brake contact when you want it is fine. brake contact just because
you happen to be deviating from a straight line is not. lightweight.

If the brake contact is minimal, the efficiency loss is also
minimal. Duh!


eh? so by that rationale, it's ok if my inner tubes leak a little
bit when i corner?

But they do! Just not enough to matter in practical terms.

not as a function of cornering they don't!

Are you sure? Does not the tube deform to some extent during cornering,
and does not a localize thinning of the tube wall from that deformation
allow a SLIGHTLY higher rate of air loss, since there is less material
for the air to diffuse through? If the effect is below the resolution of
your tire pressure gauge, how would you know?

Can "jim" find the proper analogy here?

how about if my chain skips 1 tooth in 100?

How about if your chain skips 1 tooth in 1,000,000? Is that a problem?
What about skipping 1 tooth in 1,000,000,000,000,000? Is that a problem?

you're just bull****ting to "defend" a dumb 'bent design.

I am not a bull, so "jim's" contention is a practical impossibility.


geeze, that's weak. quit the ****ing and moaning and stick to the tech
facts. if you can.

This is from the king of insults!

--
Tom Sherman - Holstein-Friesland Bovinia
Tradition is the worst rational for action.

Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Joe Riel wrote:
jim beam writes:

and rotation produces lateral loads????? dude, you're
_badly_ confused!!!

It's a recumbent trike. It doesn't lean when cornering, so the
wheels are subjected to lateral forces.

EXACTLY! The only lean (relative to the road surface) that
occurs when turning on my TRIKE is from the greater deflection
of the outside front tire, which is small enough to have no
practical significance.

i thought it was a bike, not trike. that's what i think he
showed with a green fairing recently.

This
http://www.ransbikes.com/Gallery/Archive/images/Sherman1.jpg
is NOT the only HPV (hominid powered vehicle) I own.

that is a BIke is it not?

By definition yes.

This is my Earth Cycles Dragonflyer TRIKE:
http://www.flickr.com/photos/19704682@N08/1939606083/. When
cornering hard, there is enough deflection to cause the front
brakes to rub very slightly, producing a cool ringing sound.


how inefficient.

Wrong. Yet another "expert" with no clue.


brake contact when you want it is fine. brake contact just
because you happen to be deviating from a straight line is not.
lightweight.

If the brake contact is minimal, the efficiency loss is also
minimal. Duh!


eh? so by that rationale, it's ok if my inner tubes leak a little
bit when i corner?

But they do! Just not enough to matter in practical terms.

not as a function of cornering they don't!

Are you sure? Does not the tube deform to some extent during cornering,
and does not a localize thinning of the tube wall from that deformation
allow a SLIGHTLY higher rate of air loss, since there is less material
for the air to diffuse through? If the effect is below the resolution of
your tire pressure gauge, how would you know?

geeze what straw clutching!



Can "jim" find the proper analogy here?

how about if my chain skips 1 tooth in 100?

How about if your chain skips 1 tooth in 1,000,000? Is that a
problem? What about skipping 1 tooth in 1,000,000,000,000,000? Is
that a problem?

you're just bull****ting to "defend" a dumb 'bent design.

I am not a bull, so "jim's" contention is a practical impossibility.


geeze, that's weak. quit the ****ing and moaning and stick to the
tech facts. if you can.

This is from the king of insults!


unlike you!

"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Tom Sherman wrote:
"jim beam" wrote:
Joe Riel wrote:
jim beam writes:

and rotation produces lateral loads????? dude, you're
_badly_ confused!!!

It's a recumbent trike. It doesn't lean when cornering, so the
wheels are subjected to lateral forces.

EXACTLY! The only lean (relative to the road surface) that
occurs when turning on my TRIKE is from the greater deflection
of the outside front tire, which is small enough to have no
practical significance.

i thought it was a bike, not trike. that's what i think he
showed with a green fairing recently.

This
http://www.ransbikes.com/Gallery/Archive/images/Sherman1.jpg
is NOT the only HPV (hominid powered vehicle) I own.

that is a BIke is it not?

By definition yes.

This is my Earth Cycles Dragonflyer TRIKE:
http://www.flickr.com/photos/19704682@N08/1939606083/. When
cornering hard, there is enough deflection to cause the front
brakes to rub very slightly, producing a cool ringing sound.


how inefficient.

Wrong. Yet another "expert" with no clue.


brake contact when you want it is fine. brake contact just
because you happen to be deviating from a straight line is not.
lightweight.

If the brake contact is minimal, the efficiency loss is also
minimal. Duh!


eh? so by that rationale, it's ok if my inner tubes leak a little
bit when i corner?

But they do! Just not enough to matter in practical terms.

not as a function of cornering they don't!

Are you sure? Does not the tube deform to some extent during
cornering, and does not a localize thinning of the tube wall from that
deformation allow a SLIGHTLY higher rate of air loss, since there is
less material for the air to diffuse through? If the effect is below
the resolution of your tire pressure gauge, how would you know?

geeze what straw clutching!

Not at all. I deliberately choose an insignificant effect as an analogy.

Can "jim" find the proper analogy here?

how about if my chain skips 1 tooth in 100?

How about if your chain skips 1 tooth in 1,000,000? Is that a
problem? What about skipping 1 tooth in 1,000,000,000,000,000? Is
that a problem?

you're just bull****ting to "defend" a dumb 'bent design.

I am not a bull, so "jim's" contention is a practical impossibility.


geeze, that's weak. quit the ****ing and moaning and stick to the
tech facts. if you can.

This is from the king of insults!


unlike you!

I do not snipe behind the facade of a sock puppet.

--
Tom Sherman - Holstein-Friesland Bovinia
Tradition is the worst rational for action.

On Nov 8, 8:27 am, Ben C wrote:
On 2007-11-08, Tom Sherman wrote:
[...]

I still want to know how the purity level of torque is determined.

"Pure torque" usually means torque around some axis without any force at
that axis.

Example: if you hit a baseball with just the right part of the bat, it
will experience a "pure torque" around the axis on which you are holding
it. Hit it too far up or too far down and the bat will jump out of your
hands or be rammed back into them-- force as well as torque at that
axis.

Actually, this is an example of pure force, and zero
torque. If you hit the ball so that it impacts at the
center of mass of the bat, the reaction force of ball
on bat exerts zero torque about the center of mass
of the bat. If you hit it off the center of mass, there
is a torque which tries to rotate the bat about the
center of mass, which is what makes the bat feel
like it is twisting out of your hands.

As for bicycle wheels, in normal use I don't think they ever experience
pure torques around their axles.

A pure torque would be one that rotated the wheel but where the axle
exerted no linear force at all on the dropout. Accelerating will pull
the rear axle into the front of the rear dropout, braking on either
wheel will push the axle roughly into the rear of the dropout (unless
you have disk brakes).

Disc brakes still push the wheel back if they are mounted
above the axle.

Both chain drive and single-caliper disc brakes put a
side load on the axle/wheel. The effect of tying and
soldering on these considerations, for all practical
purposes, could be simulated by wedging peas into
the spoke crossings; only the fairytale princess
could tell the difference.

Ben

If you get an assistant to lift the front of the bike in the air, then
grip the front wheel with both hands at opposing positions and turn it
smoothly like a steering wheel, that's a pure torque.

On 2007-11-10, wrote:
On Nov 8, 8:27 am, Ben C wrote:
On 2007-11-08, Tom Sherman wrote:
[...]

I still want to know how the purity level of torque is determined.

"Pure torque" usually means torque around some axis without any force at
that axis.

Example: if you hit a baseball with just the right part of the bat, it
will experience a "pure torque" around the axis on which you are holding
it. Hit it too far up or too far down and the bat will jump out of your
hands or be rammed back into them-- force as well as torque at that
axis.

Actually, this is an example of pure force, and zero
torque.

No, it's force and torque at the COM, torque only at the handle.

If you hit the ball so that it impacts at the
center of mass of the bat, the reaction force of ball
on bat exerts zero torque about the center of mass
of the bat.

Yes, but that's no good because you're not holding the bat at the centre
of mass.

If the ball hits the COM and you're holding the handle, the bat will
jump forwards out of your hands.

If you hold the bat in some given place (i.e. the handle) that defines a
"centre of percussion" which is the place where if the ball hits it
there there will be torque but no force where you're holding it. The COP
is not in the same place as the COM unless you're also holding it at the
COM (but then the ball would hit your fingers).

If you hit it off the center of mass, there
is a torque which tries to rotate the bat about the
center of mass, which is what makes the bat feel
like it is twisting out of your hands.

No, the "sweet spot" does involve torque around the COM, but not around
where you're holding it.

This is a nice demo:

http://www.physics.brown.edu/physics...os/1q3051.html

This is slightly different from the common case because normally torque
is measured around the COM. For a wheel, the axle goes through the COM
anyway.

But the concept of "torque but no force == pure torque" is the same. I
first heard of it in the context of discussion of centre of percussion
which is why I gave that example.

As for bicycle wheels, in normal use I don't think they ever experience
pure torques around their axles.

A pure torque would be one that rotated the wheel but where the axle
exerted no linear force at all on the dropout. Accelerating will pull
the rear axle into the front of the rear dropout, braking on either
wheel will push the axle roughly into the rear of the dropout (unless
you have disk brakes).

Disc brakes still push the wheel back if they are mounted
above the axle.

Both chain drive and single-caliper disc brakes put a
side load on the axle/wheel. The effect of tying and
soldering on these considerations, for all practical
purposes, could be simulated by wedging peas into
the spoke crossings;

I must try that sometime!

Ben C? wrote:
...
But the concept of "torque but no force == pure torque" is the same....

butbutbut, torque is force multiplied by the length of the couple, e.g.
if a cyclist puts a force of 900N on the end of a 0.180 m crank, the
resulting torque is 162N-m. Torque without force is by definition
impossible.

--
Tom Sherman - Holstein-Friesland Bovinia
Tradition is the worst rational for action.

On 2007-11-10, Tom Sherman wrote:
Ben C? wrote:
...
But the concept of "torque but no force == pure torque" is the same....

butbutbut, torque is force multiplied by the length of the couple, e.g.
if a cyclist puts a force of 900N on the end of a 0.180 m crank, the
resulting torque is 162N-m. Torque without force is by definition
impossible.

Yes of course, in that sense.

It's a question of how you analyze the situation. It's quite common to
break down the action of a force on the surface of a rigid body
somewhere into a force acting through the centre of mass plus a torque
about the centre of mass.

Pure force is when the force acts on a line intersecting the COM (so
there is no torque about the COM). Pure torque is when there is no force
at the axis of rotation, but there is a torque. To get a pure torque
you'd need to apply a "couple" or pair of forces.

Thought experiment: a big spaceship in space somewhere. Drill a straight
hole through it that goes through the COM. Thread a wire or something
through the hole, not touching the sides. Apply forces to the spaceship.
If you can get it to spin without the wire touching the sides of the
hole, you're applying a pure torque.

On Thu, 08 Nov 2007 20:04:23 -0600, in rec.bicycles.tech Tom Sherman
wrote:

We have established that "jim beam" believes the newton to be a unit of
torque!

I had a hampster named "Newton" once. And Newtons would be a a
component of torque, of course.

....do y'all ever trim the quotes out of the thread?

Jones