Spoke Tensiometer questions
VCopelan
buying one. I've been looking at three different spoke tensiometers. The Park
tool at under $50, the Wheelsmith tool at around $120, and the DT Proline dial
tensiometer at $250. I've read the critical comments about the Park tool from
Jobst Brandt. The Wheelsmith and Park tool appear similiar. Which tool should
I consider?
jobst....@stanfordalumni.org
> Wheelsmith and Park tool appear similar. Which tool should I
> consider?
If you do this much, the Wheelsmith tensiometer is the easiest and
quickest to use. It isn't easily readable and convertible but it is
accurate and fast (handy). It was invented by Norm Ogle who was a
great talent in such things. The simplicity and durability of the
instrument should receive design awards.
That said, it was too bad that its measurement includes the spoke
thickness, but then I can't suggest a way of getting past that with
the design at hand.
Jobst Brandt
jobst....@stanfordalumni.org
VCopelan
>If you do this much, the Wheelsmith tensiometer is the easiest and
>quickest to use. It isn't easily readable and convertible but it is
>accurate and fast (handy). It was invented by Norm Ogle who was a
>great talent in such things. The simplicity and durability of the
>instrument should receive design awards.
Thanks for the reply. I'd really like to buy the DT Proline tensiometer. It's
just the price tag that's slowing me down.
Tim McNamara
I have the Wheelsmith tool, and zero it out on a free spoke from the
set I am going to use in the wheel (I don't know if this is actually
helpful, BTW). As Jobst says, it's quick. However, I really just use
it to set and check the tension of one spoke and compare the rest of
the spokes to that one by plucking and listening to the pitch of the
spoke. Much faster than applying the tool to each spoke. Every pass
around the wheel, I recheck the tension of the "master" spoke (which
is next to the valve hole to keep track of it easily).
Qui si parla Campagnolo
considering
buying one. I've been looking at three different spoke tensiometers. The Park
tool at under $50, the Wheelsmith tool at around $120, and the DT Proline dial
After using the Wheelsmith one for years, I got the DT one and it is a
'Porsche' of tensionometers(the Wheelsmith one being a Toyota). Feels ohh so
nice in the hand, easy to use/read, really a nice piece of gear. If ya build a
lot of wheels, and can afford it, get the DT one.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
Tom Sherman
>
> After using the Wheelsmith one for years, I got the DT one and it is a
> 'Porsche' of tensionometers(the Wheelsmith one being a Toyota). Feels ohh so
> nice in the hand, easy to use/read, really a nice piece of gear. If ya build a
> lot of wheels, and can afford it, get the DT one.
So using the above analogy, the DT spoke tensiometer is overpriced, not
as reliable as it should be, outrageously expensive to maintain, and
purchased mainly for status value, while the Wheelsmith spoke
tensiometer is fairly priced, about as reliable as reasonably possible,
of average expense to maintain, and purchased by people who appreciate
its value.
For what it is worth, Porsche was headed towards bankruptcy a few years
back, but was saved by changes suggested by a consulting firm formed of
retired Toyota executives.
Tom Sherman - Quad Cities (Illinois Side)
jobst....@stanfordalumni.org
That's a lot of myth and lore. The company was saved by actions by
Ferdinand Piech, grandson of Ferdiand Porsche and CEO of VW-Audi, who
was instrumental in getting Wendelin Wiedeking to take over the
company:
http://automobile.karrierefuehrer.de/boxenstopp_porsche-wiedeking.shtml
http://www.businessweek.com/1998/02/b3560016.htm
Piech was the man who developed the Porsche 917 and later
the fastest, most powerful car on the production GT market with 1003hp
and 400km/h, the Bugatti Veyron:
http://members.fortunecity.com/freecarwallpapers/bugatti_01.htm
http://www.car-data.com/xpage.preview/pre.template.asp?mfg=bugatti&model=veyron
Bugatti Veyron 16/4
-----------------------------
Year: 2001
Power: 1001 HP
Cylinders: 16
Displacement: 7993 ccm
Top speed: 406 km/h
0-62 mph: 3.2 sec.
Gears: 7
Price: EUR 750,000
Jobst Brandt
jobst....@stanfordalumni.org
Tom Sherman
> Tom Sherman writes:
>
>
>>>After using the Wheelsmith one for years, I got the DT one and it
>>>is a 'Porsche' of tensionometers(the Wheelsmith one being a
>>>Toyota). Feels ohh so nice in the hand, easy to use/read, really a
>>>nice piece of gear. If ya build a lot of wheels, and can afford
>>>it, get the DT one.
>
>
>>So using the above analogy, the DT spoke tensiometer is overpriced, not
>>as reliable as it should be, outrageously expensive to maintain, and
>>purchased mainly for status value, while the Wheelsmith spoke
>>tensiometer is fairly priced, about as reliable as reasonably possible,
>>of average expense to maintain, and purchased by people who appreciate
>>its value.
>
>
>>For what it is worth, Porsche was headed towards bankruptcy a few
>>years back, but was saved by changes suggested by a consulting firm
>>formed of retired Toyota executives.
>
>
> That's a lot of myth and lore....
That maybe so, but it is not what the automotive press reported at the time.
Qui si parla Campagnolo
purchased mainly for status value, while the Wheelsmith spoke
tensiometer is fairly priced, about as reliable as reasonably possible,
Tee hee, I wondered how many posts would say somethin like this.
I would love to have a Porsche, along with my very old Rolex, instead of a
Toyota or Seiko...
Jay Beattie
<jobst....@stanfordalumni.org> wrote in message
news:v8V0c.5065$_3.7...@typhoon.sonic.net...
> Tom Sherman writes:
<snip>
> Piech was the man who developed the Porsche 917 and later
> the fastest, most powerful car on the production GT market with
1003hp
> and 400km/h, the Bugatti Veyron:
>
> http://members.fortunecity.com/freecarwallpapers/bugatti_01.htm
>
http://www.car-data.com/xpage.preview/pre.template.asp?mfg=bugatti&model=veyron
>
> Bugatti Veyron 16/4
> -----------------------------
> Year: 2001
> Power: 1001 HP
> Cylinders: 16
> Displacement: 7993 ccm
> Top speed: 406 km/h
> 0-62 mph: 3.2 sec.
> Gears: 7
> Price: EUR 750,000
Very nice, but where do you put the roof rack? -- Jay Beattie.
Carl Fogel
[snip]
>
> Piech was the man who developed the Porsche 917 and later
> the fastest, most powerful car on the production GT market with 1003hp
> and 400km/h, the Bugatti Veyron:
>
> http://members.fortunecity.com/freecarwallpapers/bugatti_01.htm
> http://www.car-data.com/xpage.preview/pre.template.asp?mfg=bugatti&model=veyron
>
> Bugatti Veyron 16/4
> -----------------------------
> Year: 2001
> Power: 1001 HP
> Cylinders: 16
> Displacement: 7993 ccm
> Top speed: 406 km/h
> 0-62 mph: 3.2 sec.
> Gears: 7
> Price: EUR 750,000
>
> Jobst Brandt
> jobst....@stanfordalumni.org
Dear Jobst,
How nice to see someone who's not fascinated by image![1]
This sensible little commuter car looks infinitely more
practical than the posturing, useless SUV's that seem to
haunt your nightmares.[2]
A thousand-and-one horsepower sounds like just the thing for
sitting in rush-hour traffic!
Carl Fogel
P.S. I want one, too.
[1]
"The machismo of shifting gears has lost favor in most civilized
places. It has nothing to do with usefulness or economy. Today,
most large SUV's and long haul trucks (you know "18-wheelers") are
automatic, as are of course, formula race cars. That these drivers
use automatics has muted the common axiom that automatics are for
women (who can't master the mechanics), the common explanation when
the subject of sporty driving (a man's thing) arises. Heel-and-toe,
double clutching and all that gratuitous hand-and foot-work of the
initiated. Give me a break. I am amazed how many men cannot get
over these juvenile ideas about manliness."
--Jobst Brandt
[2]
"It's like the black SUV with black windows. It's the IN thing."
--Jobst Brandt
"The SUV folks can defend the superiority of their vehicles with
the same rhetoric we see here defending fashionable bicycles and
their equipment." --Jobst Brandt
"Currently black is beautiful, be that rims, tires, or SUV's (with
blackened windows." --Jobst Brandt
"The reason for using these frame materials IS to get lighter and
lighter... and more expensive to increase boasting rights. It runs
parallel to the larger and larger SUV with black everything offset by
chrome." --Jobst Brandt
"Forget it and just get a bigger (black) SUV with blackened windows,
jacked up chassis, rumble pipes, and spotlights." --Jobst Brandt
"The point is that driving truck is IN, and how SUV's are designed is
much like any fashion item, it can be as frivolous as hell, and not
make any difference." --Jobst Brandt
"Because you are considering a vehicle where image is all and gimmicks
are the routine. If I took these vehicles as a model, I would have
six inch diameter chrome exhaust pipes on my car. They must be good,
I saw them on a Jimmy!" --Jobst Brandt
"You probably drive an SUV with chromed jungle grills over the front
with bumper bars to help you get to the real rough stuff to ride bike."
--Jobst Brandt
"Around here there are huge traffic jams of SUV's at schools."
--Jobst Brandt
"Many of them seem to believe the sales pitch that are common on
TV and radio for BMW and MB cars and play the role of snobs
admirably. The whole "drive truck" craze is a poor symbol of our
society. Image is everything, substance nothing for these folks."
--Jobst Brandt
"These people are the ones most susceptible to advertising for things
they don't need but buy anyway, convinced they will enhance their
stature, be that a monster SUV or a car with pseudo aerodynamic
appendages." --Jobst Brandt
"By the way, this is the excuse given for all the SUV's with
knobby tires and 4WD we see in the shopping malls and among other
things, buzzing bicyclists on the road." --Jobst Brandt
"Hey, you're catching on. The jacked up monster truck with oversized
tires was once in the domain of the macho guys that put padding in
their jock strap or tape a salami onto their leg. Today, the closet
admirers of thes vehicles have come out of the closet and join the
bunch, now that you can buy them off the shelf, with darkened windows
if you want. "Git outta mah way, peon! Ah've go a big tough Jimmy!"
if you haven't noticed."
"Posturing is IN! No need for substance, when appearances are taken
in lieu of."
--Jobst Brandt
"Many ride MTB's for the same reason they drive truck. SUV for you and
me! "Me and my Jimmy can go anywhere." I'm tough! What??? You
don't drive truck? Who do you think you are anyway? Besides, my
truck is diesel and has duals and a long cab and a Knaak toolbox. You
ought to hear it rumble. Even the tires make more noise than a
motorcycle. My truck is so tall I have a step ladder for passengers
and the bumper is higher than a Miyata's roof. Me and Arnold Schw.
understand big cars." --Jobst Brandt
jobst....@stanfordalumni.org
>>> For what it is worth, Porsche was headed towards bankruptcy a few
>>> years back, but was saved by changes suggested by a consulting
>>> firm formed of retired Toyota executives.
>> That's a lot of myth and lore. The company was saved by actions by
>> Ferdinand Piech, grandson of Ferdiand Porsche and CEO of VW-Audi,
>> who was instrumental in getting Wendelin Wiedeking to take over the
>> company:
>> Piech was the man who developed the Porsche 917 and later the
>> fastest, most powerful car on the production GT market with 1003hp
>> and 400km/h, the Bugatti Veyron:
http://members.fortunecity.com/freecarwallpapers/bugatti_01.htm
http://www.car-data.com/xpage.preview/pre.template.asp?mfg=bugatti&model=veyron
>> Bugatti Veyron 16/4
>> -----------------------------
>> Year: 2001
>> Power: 1001 HP
>> Cylinders: 16
>> Displacement: 7993 ccm
>> Top speed: 406 km/h
>> 0-62 mph: 3.2 sec.
>> Gears: 7
>> Price: EUR 750,000
> How nice to see someone who's not fascinated by image![1]
The whole Porsche business thrives mostly on an image based on its
history in competition with high performance cars. Some people like
to own such vehicles, the point here is that the company was not a
fabrication of Toyota but rather one man's business and technical
acumen. Under Piech, VW-Audi came from the Golf/Rabbit to a leading
auto maker competing in all catagories from Polo to Audi to Bently and
Bugatti.
Whether you want to own an expensive two seaters or not is yor
prerogative. I can do wothout it. However, I found working at
Porsche, designing a formula-1 car, challenging and educational for my
engineering carreer. I learned a lot and had the pleasure of working
with talented people. Our car, Driven by Dan Gurney, won a GP before
Mr. Porsche decided the sport was too expensive for the small company.
http://www.gpracing.net192.com/cars/data/496.cfm
> This sensible little commuter car looks infinitely more practical
> than the posturing, useless SUV's that seem to haunt your
> nightmares.[2]
> A thousand-and-one horsepower sounds like just the thing for
> sitting in rush-hour traffic!
> Carl Fogel
> P.S. I want one, too.
So having done such a great research on the web, I see you found no
inconsistencies in my appraisal of truck owners. What does this have
to do with Toyota advising Porsche on how to run their business?
Jobst Brandt
jobst....@stanfordalumni.org
Dave Kahn
> > Piech was the man who developed the Porsche 917 and later
> > the fastest, most powerful car on the production GT market with
> > 1003hp and 400km/h, the Bugatti Veyron:
> Very nice, but where do you put the roof rack? -- Jay Beattie.
If you look closely you will see there is a convenient luggage rack
behind the rear window.
--
Dave...
Carl Fogel
[snip]
> What does this have
> to do with Toyota advising Porsche on how to run their business?
>
Dear Jobst,
Gosh, I thought I saw a fellow drooling at the
sight of a thousand-and-one horsepower sports
car and wondered what it had to do with Toyota
advising Porsche how to run their business.
Usually, he's ranting in rec.bicycles.tech about
how silly some kind of overpowered, overpriced
cars are. He calls them SUV's and Jimmys.
Sorry--he really looked like you.
Carl Fogel
Bikefixr
tension is not important-eveness of tension around the wheel IS important. If
you measured the same wheel with 3 different tensiometers, you'll get 3 very
different measures. So which one is right? In practice, it doesn't matter. What
they are good for is draining your wallet and for novice builders who don;t
have any "feel" yet. It might help keep them out of trouble, but I doubt it.
In 20 yrs of wheelbuilding, I have never once seen an amateur wheel I would
ride on. Hell, I wouldn't have ridden MY first 20 wheels or so... So I suggest
that you lace up, tension up. Keep as true and round as possible as you tension
up, lube the nipple-rim interface regularly. I use subjective feel and sound. A
human ear can hear far more subtle differences than the hand can feel. When
they all feel the same, sound the same, I do minor tweaks and it's ready to
roll. 8,000 pr later I've never had a wheel failure. I say keep doin' what
you're doin' and comfortable with and refine your touch.
Ted Bennett
Sixteen thousand wheels and you don't stress relieve? Don't you get
complaints about broken spokes?
--
Ted Bennett
Portland OR
BaCardi
I have the Park tensionometer. I almost got the Wheelsmith brand,
but tried the Park and it works great. I couldn't really justify
spending more on the Wheelsmith one, when the Park does the same
thing at half the cost.
I'm kinda in agreement with the other guy. You'll find that you really
only use it for a few spokes to make sure that they are up to the
tension you are aiming for. The rest of the spokes you just want to be
sure that they are evenly tensioned. You don't really need it, but I
like mine because I am certain that I am in the range, tensionwise, that
I set out to be in when I build the wheels.
--
A Muzi
>>You've been building wheels for years. Why bother with a tensiometer?
>>Absolute
>>tension is not important-eveness of tension around the wheel IS important.
>>When they all feel the same, sound the same, I do minor tweaks and it's ready to
>>roll. 8,000 pr later I've never had a wheel failure. I say keep doin' what
>>you're doin' and comfortable with and refine your touch.
Ted Bennett wrote:
> Sixteen thousand wheels and you don't stress relieve? Don't you get
> complaints about broken spokes?
Before The Book, we stress-relieved effectively because the
theory at the time was that you had to pull the spokes hard
to bed the curve into the hubshell -so the mating surface
was larger than a point. Either way we pulled them very
tight in pairs before final tension for ten years before
reading why.
Perhaps bikfixr's "minor tweaks" involve momentarily raising
spoke tension with his hands similarly.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
Qui si parla Campagnolo
tensiometer? Absolute
tension is not important-eveness of tension around the wheel IS important.
Not quite. Even tension at 75% of what the tension should be makes for a porr
wheel.
bikefixr<< What
they are good for is draining your wallet and for novice builders who don;t
have any "feel" yet. >><BR><BR>
I have been building wheels for 19 years and altho I can 'feel' tension pretty
close, i still use a tensionometer on every wheel I either build or true.
bikefixr<< I use subjective feel and sound.
Are your hands tired at the end of the day? Mine are, does feel change?
A tensionometer, not expensive, particularly when used for years, will
certainly not make his wheels poorer.
Tim McNamara
> You've been building wheels for years. Why bother with a
> tensiometer? Absolute tension is not important-eveness of tension
> around the wheel IS important. If you measured the same wheel with 3
> different tensiometers, you'll get 3 very different measures. So
> which one is right?
Reminds me of the Chinese proverb: a man with a clock knows what
time it is; a man with two clocks is never sure.
> In practice, it doesn't matter. What they are good for is draining
> your wallet and for novice builders who don't have any "feel"
> yet. It might help keep them out of trouble, but I doubt it.
Why so cynical? It is actually helpful for beginners to prevent gross
under- or over-tensioning without having to deform a rim in the
process.
> In 20 yrs of wheelbuilding, I have never once seen an amateur wheel
> I would ride on.
So you wouldn't ride one of Jobst's wheels?
> Hell, I wouldn't have ridden MY first 20 wheels or so...
Presumably somebody did.
> So I suggest that you lace up, tension up. Keep as true and round as
> possible as you tension up, lube the nipple-rim interface
> regularly. I use subjective feel and sound. A human ear can hear far
> more subtle differences than the hand can feel. When they all feel
> the same, sound the same, I do minor tweaks and it's ready to
> roll. 8,000 pr later I've never had a wheel failure. I say keep
> doin' what you're doin' and comfortable with and refine your touch.
While much of what you say is true- especially the sensitivity of
judging relative tension by plucking spokes and listening to the
pitch- for the average person building a few wheels for themselves
this sort of proficiency will never develop. I've built hundreds of
wheels, but I can't tell if they're adequately tensioned just by
plucking a spoke or squeezing them. They could be significantly
undertensioned and still sound or feel OK, depending on a number of
factors (wheel size, pattern, spoke gauge, etc).
Oddly enough, you don't recommend stress relieving, probably the
single most important step you can take for ensuring good service
life of the spokes.
Carl Fogel
Dear Tim,
It's curious how many people feel that there are
some things that man was never meant to measure
with anything but the seat of his pants, like spoke
tension.
Oddly enough, the stress-relief of spokes that you call
the single most important step may be one of these sacred
cows:
"The fatigue resistance of spokes was not tested for
lack of suitable equipment." ("The Bicycle Wheel," 2nd
edition, Part III, "Equations and Tests")
And the stress-strain graphs of the tests of actual
stainless steel spokes in that section (figure 69)
don't look at all like the stress-strain graph used
to explain elastic limits (figure 15). The curves
of the actual spoke tests just climb toward failure
without any intermediate drop at an elastic limit
(which I gather is the normal behavior of stainless
steel--it shows no elastic limit).
Perhaps the third edition addressed this?
To be honest, I can't see any objective
difference between checking tension by ear
(bikefixr's approach) and grabbing spoke pairs
and giving 'em a good squeeze to relieve tension
(current received wisdom on rec.bicycles.tech).
Are there any studies showing actual results for
these seat-of-the-pants approaches? That is,
someone showing his ear to be as good at measuring
tension as a high-quality tensiometer, or someone
showing measurable effects from spoke-squeezing?
Either method may work. Anyone who can tune a violin
can see the idea behind spoke-plucking, and a healthy
squeeze might relieve some kind of tension in a spoke
already under 200 to 500 lbs of tension.
I'm just curious if anyone has ever demonstrated
that either method works in a fashion that could be
presented and repeated in an engineering course.
Carl Fogel
Tim McNamara
> It's curious how many people feel that there are some things that
> man was never meant to measure with anything but the seat of his
> pants, like spoke tension.
Well, as I mentioned in the other thread, experience results in
perceptual learning. There's a biological limit to how fine-grained
perception can be (and even that can be overcome to a degree- for
example, vascular surgeons using visual magnifying equipment can make
tiny, accurate movements that would not be possible without
magnification).
> Oddly enough, the stress-relief of spokes that you call the single
> most important step may be one of these sacred cows:
>
> "The fatigue resistance of spokes was not tested for lack of
> suitable equipment." ("The Bicycle Wheel," 2nd edition, Part III,
> "Equations and Tests")
>
> And the stress-strain graphs of the tests of actual stainless steel
> spokes in that section (figure 69) don't look at all like the
> stress-strain graph used to explain elastic limits (figure 15). The
> curves of the actual spoke tests just climb toward failure without
> any intermediate drop at an elastic limit (which I gather is the
> normal behavior of stainless steel--it shows no elastic limit).
>
> Perhaps the third edition addressed this?
You'd have to ask Jobst, eh?
> To be honest, I can't see any objective difference between checking
> tension by ear (bikefixr's approach) and grabbing spoke pairs and
> giving 'em a good squeeze to relieve tension (current received
> wisdom on rec.bicycles.tech).
Oops, apples and oranges. Stress relieving is basically cold setting
the spokes to relieve residual stresses that remain in the metal from
the process of forming the elbow and head (as I understand it,
anyway). What bikefixr is talking about is judging spoke tension by
ear, which is unrelated to stress relieving.
> Are there any studies showing actual results for these
> seat-of-the-pants approaches? That is, someone showing his ear to be
> as good at measuring tension as a high-quality tensiometer, or
> someone showing measurable effects from spoke-squeezing?
This is not a scientific study by any means, but in my personal
experience I can hear differences in spoke tension that do not
register on my Wheelsmith tensiometer. The change in pitch caused by
changing tension on a wire is mathematically a very precise
relationship. It's the same as tuning a stringed instrument, in
whcih case again the ear is more sensitive than measuring the string
tension. I don't have any specific studies I can refer you to, this
is from my undegrad class in perception umpteen years ago. Come to
think of it, though, there was a thread on this a couple of years ago
and I had dug out my old textbooks to look up the sensitivy of the
ear to pitch changes.
> Either method may work. Anyone who can tune a violin can see the
> idea behind spoke-plucking, and a healthy squeeze might relieve some
> kind of tension in a spoke already under 200 to 500 lbs of tension.
Again, apples and oranges.
> I'm just curious if anyone has ever demonstrated that either method
> works in a fashion that could be presented and repeated in an
> engineering course.
You'd have to ask Jobst if his stress relieving technique causes a
high enough momentary increase in tension to cold set the spoke
material. But that's a different question than judging spoke tension
by pitch.
jobst....@stanfordalumni.org
> You've been building wheels for years. Why bother with a
> tensiometer? Absolute tension is not important-eveness of tension
> around the wheel IS important.
That's an interesting concept. And how tight is right? I suspect
from what you say that you are unaware that wheel strength is a direct
function of spoke tension and that this should be as high as a rim
safely permits. That level of tension is not easily assessed by any
other means than a tensiometer. Maybe you have another method and
should let others know what it is. I have described a method to find
that upper safe limit but I don't propose to use it for successive
wheels once that tension has been determined.
> If you measured the same wheel with 3 different tensiometers, you'll
> get 3 very different measures. So which one is right?
That's not the point. The point is repeatability and protection from
over or under tensioning. That works with a completely uncalibrated
instrument. However, the correct tension must be determined at some
time. Even your' claimed difference in tensiometers is in my
experience not significant compared to guesses by people who as you
suggest, don't believe tension is important.
> In practice, it doesn't matter. What they are good for is draining
> your wallet and for novice builders who don;t have any "feel" yet.
> It might help keep them out of trouble, but I doubt it.
I see that you think engineers and engineering incompetent to define
what a structure should be while mechanics who have been repeating the
same errors for many years are appropriate mentors. What gives you
this aversion to education and the scientific method?
> In 20 yrs of wheelbuilding, I have never once seen an amateur wheel
> I would ride on. Hell, I wouldn't have ridden MY first 20 wheels or
> so...
That's not saying much for your understanding of wheels. I know many
people who have ridden their first wheels for many tens of thousand
miles. Not being bicycle mechanics did not stand in their way to
building good and durable wheels. It only takes reading ability, and
a bit of manual dexterity. I notice on occasion that bicycle shops
that sell a wheel building book do not read it themselves for the
reasons that you seem to express.
> So I suggest that you lace up, tension up. Keep as true and
> round as possible as you tension up, lube the nipple-rim interface
> regularly. I use subjective feel and sound. A human ear can hear
> far more subtle differences than the hand can feel. When they all
> feel the same, sound the same, I do minor tweaks and it's ready to
> roll. 8,000 pr later I've never had a wheel failure. I say keep
> doin' what you're doin' and comfortable with and refine your touch.
That's a nice testimonial but not much in the way of how tight a wheel
should be for someone who hasn't built many wheels.
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
> It's curious how many people feel that there are some things that
> man was never meant to measure with anything but the seat of his
> pants, like spoke tension.
> Oddly enough, the stress-relief of spokes that you call the single
> most important step may be one of these sacred cows:
> "The fatigue resistance of spokes was not tested for lack of
> suitable equipment." ("The Bicycle Wheel," 2nd edition, Part III,
> "Equations and Tests")
Maybe instead of repeating this quote ominously, you might add what
you think you would gain from a fatigue test of a specific spoke in a
text about building wheels. The book has been in print a long time
and its fatigue values would even when new not reveal what spokes to
use for a given wheel. How do you propose testing spoke fatigue?
> And the stress-strain graphs of the tests of actual stainless steel
> spokes in that section (figure 69) don't look at all like the
> stress-strain graph used to explain elastic limits (figure 15). The
> curves of the actual spoke tests just climb toward failure without
> any intermediate drop at an elastic limit (which I gather is the
> normal behavior of stainless steel--it shows no elastic limit).
To what are you alluding? These are curves taken directly from a
tensile tester. The reason for their presence is that the long yield
elongation of the DT spoke shows its ductility and that it does not
strain harden in use because the wire has already been work hardened
to its highest value and is still ductile enough to be cold formed.
> Perhaps the third edition addressed this?
I see you are piqued and keep needling, just as Wheelsmith did in his
review of the book many years ago, claiming the book was incomplete
and therefore more or less useless. It seems you are taking over his
position in that respect.
> To be honest, I can't see any objective difference between checking
> tension by ear (bikefixr's approach) and grabbing spoke pairs and
> giving 'em a good squeeze to relieve tension (current received
> wisdom on rec.bicycles.tech).
"Giving 'em a good squeeze" is not to relieve tension (it does not)
nor is using a tensiometer. You can delete the "to be honest" in you
chiding manner, it only suggests that what else you say without that
preface is untrue, or at least that you have not said all of the above
with fill candor.
> Are there any studies showing actual results for these
> seat-of-the-pants approaches? That is, someone showing his ear to be
> as good at measuring tension as a high-quality tensiometer, or
> someone showing measurable effects from spoke-squeezing?
The reason this is not so is that there are many spoke arrangements,
crossed, radial, interleaved or not and a great variety of rims and
number of spokes, but you knew that because it has all been here in
this forum before, something that you seem to be good at digging up
from Google when you think it might support your point of view. That
point of view remaining silent although obvious from many allusions.
> Either method may work. Anyone who can tune a violin can see the
> idea behind spoke-plucking, and a healthy squeeze might relieve some
> kind of tension in a spoke already under 200 to 500 lbs of tension.
You don't need to list all the things that "may work" they being
myriad and little use to those reading this newsgroup. Your ploy of
raising and army of straw men to discredit proven methods and
confusing these with old wive's tales, is not doing us any favors,
especially when you occasionally claim ignorance of science as you
ramble on in plaintiff's attorney style.
> I'm just curious if anyone has ever demonstrated that either method
> works in a fashion that could be presented and repeated in an
> engineering course.
Can you repeat the WHOLE question in plain English so it is evident
what it is you don't understand?
Jobst Brandt
jobst....@stanfordalumni.org
jim beam
> Carl Fogel writes:
>
>
>>It's curious how many people feel that there are some things that
>>man was never meant to measure with anything but the seat of his
>>pants, like spoke tension.
>
>
>>Oddly enough, the stress-relief of spokes that you call the single
>>most important step may be one of these sacred cows:
>
>
>>"The fatigue resistance of spokes was not tested for lack of
>>suitable equipment." ("The Bicycle Wheel," 2nd edition, Part III,
>>"Equations and Tests")
>
>
> Maybe instead of repeating this quote ominously, you might add what
> you think you would gain from a fatigue test of a specific spoke in a
> text about building wheels. The book has been in print a long time
> and its fatigue values would even when new not reveal what spokes to
> use for a given wheel. How do you propose testing spoke fatigue?
to be fair jobst, i think some spoke fatigue testing would be a good
thing. if nothing else, it will give some comparative measures on
whether the different manufacturing methods and materials used by
wheelsmith, d.t., sapim, etc make any difference to their fatigue lives.
>
>
>>And the stress-strain graphs of the tests of actual stainless steel
>>spokes in that section (figure 69) don't look at all like the
>>stress-strain graph used to explain elastic limits (figure 15). The
>>curves of the actual spoke tests just climb toward failure without
>>any intermediate drop at an elastic limit (which I gather is the
>>normal behavior of stainless steel--it shows no elastic limit).
>
>
> To what are you alluding? These are curves taken directly from a
> tensile tester. The reason for their presence is that the long yield
> elongation of the DT spoke shows its ductility and that it does not
> strain harden in use because the wire has already been work hardened
> to its highest value and is still ductile enough to be cold formed.
"shows its ductility and that it does not strain harden in use"??? your
graphs /do/ show a plastic deformation zone above the elastic yield
point, do they not? and that region continues to rise for stress for
some strain percentage before u.t.s.? that's continuing cold work
continuing to harden the material and consuming the last of the
materials ductility.
unless you have a precipitation hardening material, which spoke wire is
not afaik, the /only/ hardening is from cold work. there is no strain
aging. any continuing cold work [i.e. any plastic deformation, not
fatigue] continues to harden, unless you are at u.t.s. no spoke is at
uts - your own graphs prove that. "already work hardened to its highest
value" is directly contradictory to "still ductile enough to be cold
Carl Fogel
Dear Jobst,
You seem to have replied at considerable length
to a question that you claim not to understand.
Since you didn't answer it, I almost believe you.
Carl Fogel