The Basics of Wheel Alignment and Wheelbuilding

Jose Rizal wrote in message ...

Just how do you do this, and how do you account for the dynamic loads
put on the wheel which exceed the static rider/bike weight?

Put water into pan, light gas, place egg in water, bring to boil, turn off
gas.
It would help if questions were more spcific than how do you do this?
specifically which part of my explanation do you think requires further
explanation?
7/5(rider+bike+load) Front wheel loading.
As another answer explains it is a simple matter to tension the wheel a bit
more if the rider finds the wheel wobbly.

What the hell is "a wheel which will fail safe"?

Will not lock up in the frame due to buckling.


Since buckling is also load magnitude dependent, "severre" buckling
cannot be avoided if the load is high enough, and especially since you
only tensioned the spokes enough to take up your static weight.

Spoke quality is not an issue.

Plastic spokes will be fine then.

Steel is an excellent material for bicycle spokes. Plastics are not
renowned for their ability to work in tension and I doubt any plastic could
replace the steel spoke. Aramid fibre of course is exceptionally strong and
may provide an alternative at increased cost.
TJ

On 31 Jul 2004 00:58:09 -0700, Benjamin Weiner
wrote:

[snip]


Carl, did you see in the discussion at
http://yarchive.net/bike/stress_relieve.html
the article containing this quote and link

"For some results of some actual residual stress measurements I did on
7050 aluminum plate before and after stretching see:
http://www.lanl.gov/residual/alplate.pdf
The residual stress was reduced by about a factor of 10 by the stress
relief process."


Dear Benjamin,

Yes, I've seen the thread and looked at the link to the
test. While I can't recall where I read it, others pointed
out a few potential problems.

The test involved a comparatively massive metal slab, about
6 inches square and 3 inches thick, not a spoke about a
tenth of an inch thick. (My naive guess would be that this
size difference wouldn't matter because the flaws are
microscopic, but a materials engineer suggested that it
might.)

The test slab was cut out of a much larger piece that was
"rolled," so it was worked to some degree, but it may not
have been as heavily worked as a bicycle spoke. (This
sounded more plausible to me, but it wouldn't surprise me to
learn that the rolling of the slab worked it just as much or
more as the production of a spoke works a spoke.)

The metal tested was aluminum, not stainless steel. (I know
that the two metals are similar in that neither shows a
yield point on a stress-strain test, but are different in
that aluminum ain't stainless steel. I also know that
aluminum and steel have different fatigue characteristics
when used in frames and that I don't have the slightest
idea whether any of this matters in comparing the aluminum
slab to the stainless steel spoke.)

The question of how much "stretching" was used on the test
slab versus how much "squeeze" (same idea) is used by a
typical bicycle wheel builder was not addressed. The slab
was stretched 1.5% to 3% in the rolling direction, but how
much a spoke is stretched by the squeeze method is unclear.
(My own vague notion is that a good squeeze should stretch a
pair of 300mm spokes that much.)

What the stretching does to the material in terms of final
dimensions was also debated. My naive impression was that
both the stretched test plate and the squeezed spokes are
tensioned only elastically and snap back to their original
length when tension is released--that is, there's no
permanent elongation. However, others have suggested that
releasing any stress involves permanent changes in
dimensions, microscopic or not. Damned if I know the answer.

A final question concerned the quenching of the aluminum
plate (I think that you have to go to the later version of
the test to see this) and whether quenching aluminum creates
far more internal stress than would be found in spokes and
whether such a difference makes any comparison a matter of
apples and oranges. Again, I don't know enough about metals
to even hazard a guess--I have a hazy notion that spokes are
cold worked, not quenched, but whether this matters to
stress is a mystery to me.

None of these objections, as I recall, were meant to cast
any doubt on Mike Prime's aluminum plate test itself, which
was not undertaken to address the stainless steel spoke
question and seems like a reasonable test to bring up. They
were raised to point out that the two situations may differ
in significant ways (and were also raised probably for the
joy of quibbling, not that we ever see any of that on
rec.bicycles.tech).

The trouble is probably that the question of spoke fatigue
is trickier than we'd like it to be. Various explanations
exist, each with fierce partisans, but testing of the kind
that would stand up in a high school physics class seems to
be hard to find, partly because the testing is likely to be
much harder than expected, partly because the subject is
much more complicated than it might seem at first, and
partly because the question is not exactly crucial.

I often wonder whether my wavering on this matter resembles
what I had to endure with people debating who wrote
Shakespeare. I'm not sure who's right about spoke squeezing,
so I long for a site that patiently goes through the details
for the layman in the way that this site explains literary
matters:

http://shakespeareauthorship.com

Unfortunately, not everyone is as helpful as you are, so
questions here on rec.bicycles.tech often degenerate into
mere name-calling instead of explanations. It's not much
good trying to convince a skeptical audience either way on
spoke-squeezing if all that I have is that one person says
that the other is wrong and both claim that their spokes
last forever.

The last person whom I bored to tears about spokes raised an
interesting question. If spoke-squeezing works, either by
relieving stress or by other methods, and makes spokes
practically immortal, how soon should unsqueezed spokes
break? That is, when did I predict that the unsqueezed
spokes would fail?

My muttered "sooner" was dismissed as being a bit imprecise.
I'd mentioned that some spoke squeezers claim over 50,000
miles on failure-free spokes, so my tormentor kept asking me
when he should expect his unsqueezed spokes to fail--1,000
miles, 5,000, 10,000, or even 25,000 miles?

He relented when I promised to pose the question here, so
perhaps someone will speculate on how long the spokes on
what everyone agrees is an otherwise properly built wheel
should last if not squeezed.

Carl Fogel

Trevor Jeffrey wrote:
No I do not tension spokes as high as possible. I presume therefore
that you do and so pre-load the rim so there is a tendency to buckle. There
is no advantage in pre-loading spokes and rims, it only lessens the load
capacity of the wheel before buckling.

Oh! I never could have imagined that things were so simple! I guess
all one really has to do is lace the wheel, tighten the nipples enough
to snug up the spokes, and voila: a bicycle wheel with truly tremendous
load capacity! It makes so much sense.

--
Todd Bryan
Santa Barbara, CA
bryan at cs dot utk dot edu

jim beam wrote:
wrote:


snip

Spoke-squeezing is an intriguingly mysterious subject to
research. I remain agnostic, wavering one way and the other,
but haven't seen any experimental data or analyses involving
bicycle spokes. If you have the 3rd edition, perhaps you
could peek at the Wiedemer stuff and give me your thoughts
on it?


you may also want to consider this question:

q: elevator safety certification requires loading the cab to double
it's "safe working load". this is to test the wire ropes that suspend
it. the reason is that fracture mechanics predict that this process
will typically reveal by failure any latent flaws. but, if we extend
spoke squeezing theory, wouldn't this overload procedure also prevent
fatigue of elevator cables?

a: no. elevator cables still fatigue and need regular testing,
inspection & replacement.

This proves nothing one way or the other about the affects
of squeezing spokes to reduce residual stress. There is no
question that reducing residual (tensile) stresses can
increase fatigue life. There is also no question that
spokes (or elevator cables) will still fatigue if the cyclic
load is high enough (i.e. above the endurance limit). The
question is whether squeezing the spokes provides any
significant beneficial reduction in residual stress, or
increases the endurance limit.

Mark McMaster

wrote in message ...
He relented when I promised to pose the question here, so
perhaps someone will speculate on how long the spokes on
what everyone agrees is an otherwise properly built wheel
should last if not squeezed.

It is not possible to everyone to agree on what is a properly built wheel.
I would expect spokes to last longer than it takes to wear out a road rim.
I would expect spokes to last longer than it takes to wear out 100 tyres. I
would expect spokes to last in excess of 500,000 miles with or without
overtensioning on installation.
Steel spokes are cold drawn down to a thin wire which is then annealed,
by passing through hot rollers, to remove the spring. The wire is then cut
to length, the head and thread is formed by cold working and the head
knocked over to form the bend at the end. There is a cold working through
rollers after annealing, most obviously in the form of swaged spokes
(butted).
TJ

"Trevor Jeffrey" writes:

wrote in message ...
He relented when I promised to pose the question here, so perhaps
someone will speculate on how long the spokes on what everyone
agrees is an otherwise properly built wheel should last if not
squeezed.

It is not possible to everyone to agree on what is a properly built
wheel. I would expect spokes to last longer than it takes to wear
out a road rim. I would expect spokes to last longer than it takes
to wear out 100 tyres. I would expect spokes to last in excess of
500,000 miles with or without overtensioning on installation.

You might expect it, and I might too, but plenty of experiences are
reported here that indicate spokes breaking within a few hundred or a
few thousand miles. And there are some reports of tens of thousands
of miles without spoke breakage- thus far most of these seem to be
from people who have used Brandt's method.

Steel spokes are cold drawn down to a thin wire which is then
annealed, by passing through hot rollers, to remove the spring. The
wire is then cut to length, the head and thread is formed by cold
working and the head knocked over to form the bend at the end.

This is the issue that Brandt claims his "stress relieving" procedure
addresses. He states there are residual stresses in the spoke at the
bend from the forming of the elbow. Stress relieving raises the
tension and causes cold setting, relieving those stresses. This in
turn results in spokes that last longer.

There is a cold working through rollers after annealing, most
obviously in the form of swaged spokes (butted). TJ

ISTR some spokes- DT Revolutions perhaps?- that had mid-shaft spoke
breakages because the swaging created an internal crack along the axis
of the spoke.

"Trevor Jeffrey" writes:

The use of a drying oil assists in the tensioning of spokes and the
prevention of the nipples unwinding in use.

In other words. it acts as a glue between the spoke and the nipple.
Wheelsmith sells a preparation that does a simiar thing, Spoke Prep.
Linseed oil is cheaper by orders of magnitude. I use 10w-30 motor
oil. My spoke nipples do not unwind in use, despite being 215 lbs and
riding 32 spoke wheels 6,000 to 7,000 miles a year. The reason for
this is not using something to glue the nipples and spokes together,
but using adeqate tension in the first place. Stuff like linseed oil
and Spoke Prep just covers for a badly built wheel.

Hmmm, this conversation seems like old times.

Mark McMaster wrote:
jim beam wrote:

wrote:


snip

Spoke-squeezing is an intriguingly mysterious subject to
research. I remain agnostic, wavering one way and the other,
but haven't seen any experimental data or analyses involving
bicycle spokes. If you have the 3rd edition, perhaps you
could peek at the Wiedemer stuff and give me your thoughts
on it?



you may also want to consider this question:

q: elevator safety certification requires loading the cab to double
it's "safe working load". this is to test the wire ropes that suspend
it. the reason is that fracture mechanics predict that this process
will typically reveal by failure any latent flaws. but, if we extend
spoke squeezing theory, wouldn't this overload procedure also prevent
fatigue of elevator cables?

a: no. elevator cables still fatigue and need regular testing,
inspection & replacement.


This proves nothing one way or the other about the affects of squeezing
spokes to reduce residual stress. There is no question that reducing
residual (tensile) stresses can increase fatigue life. There is also no
question that spokes (or elevator cables) will still fatigue if the
cyclic load is high enough (i.e. above the endurance limit). The
question is whether squeezing the spokes provides any significant
beneficial reduction in residual stress, or increases the endurance limit.

Mark McMaster



ah, this explains everything! stainless steel has been developed that
has an endurance limit! and it's used in bicycle spokes!!!

no. this is one of the fundamental flaws of "the book". it cites
material behavior for mild steel, which /does/ have an endurance limit,
and then presumes to describe behavior in stanless steel, which does
not. just exactly how this lends credibility to a revolutionary means
of eliminating metal fatigue is something i have yet to come to terms with.

Tim McNamara wrote:
"Trevor Jeffrey" writes:


wrote in message ...

He relented when I promised to pose the question here, so perhaps
someone will speculate on how long the spokes on what everyone
agrees is an otherwise properly built wheel should last if not
squeezed.

It is not possible to everyone to agree on what is a properly built
wheel. I would expect spokes to last longer than it takes to wear
out a road rim. I would expect spokes to last longer than it takes
to wear out 100 tyres. I would expect spokes to last in excess of
500,000 miles with or without overtensioning on installation.


You might expect it, and I might too, but plenty of experiences are
reported here that indicate spokes breaking within a few hundred or a
few thousand miles. And there are some reports of tens of thousands
of miles without spoke breakage- thus far most of these seem to be
from people who have used Brandt's method.


Steel spokes are cold drawn down to a thin wire which is then
annealed, by passing through hot rollers, to remove the spring. The
wire is then cut to length, the head and thread is formed by cold
working and the head knocked over to form the bend at the end.


This is the issue that Brandt claims his "stress relieving" procedure
addresses. He states there are residual stresses in the spoke at the
bend from the forming of the elbow. Stress relieving raises the
tension and causes cold setting, relieving those stresses. This in
turn results in spokes that last longer.

yes, but brandt also advocates "correcting the spoke line" which
involves deformation significantly above that required to stress
relieve, and indeed may leave the material with even more residual
stress than it had initially. now add to that the fact that that spoke
wire is a highly cold worked material with a very high dislocation
density [and therefore full of lattice stresses] in which any further
deformation is likely to increase dislocation density rather than reduce
it, and it becomes clear that brandt really doesn't know what he's
talking about. how else could he cite mild steel deformation
characteristics in a stainless steel application, as he does in his book?



There is a cold working through rollers after annealing, most
obviously in the form of swaged spokes (butted). TJ


ISTR some spokes- DT Revolutions perhaps?- that had mid-shaft spoke
breakages because the swaging created an internal crack along the axis
of the spoke.

jim beam wrote:

...
tim, you're like a drunken finnean looking for a bit of bare-knucked
sport on his way home from a bar. read what i said when you're sober,
then show me one single piece of metallurgical evidence to support
brandts bullying assertions. or your allusions to superior mental
health come to that.

Speaking of mental health, do you have an irrational fear of capital
letters?

--
Tom Sherman – Quad City Area