Ultra torque vs. square taper

[tbaskin@mbplaw.com]

Am contemplating a build for a custom frame. UT has been around now
since '06. What is the collective experience as to whether this
solves a problem that exists with square taper, and represents a
legitimate improvement?

tom baskin

[Tom Sherman]

tbaskin@mbplaw.com aka Tom Baskin wrote:
> Am contemplating a build for a custom frame. UT has been around now
> since '06. What is the collective experience as to whether this
> solves a problem that exists with square taper, and represents a
> legitimate improvement?

You might as well ask what the true religion is. ;)

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[Morten Reippuert Knudsen]

tbaskin@mbplaw.com wrote:
> Am contemplating a build for a custom frame. UT has been around now
> since '06. What is the collective experience as to whether this
> solves a problem that exists with square taper

witch problems?

> and represents a legitimate improvement?

It way ligther. but bearring sealing is rubbish compared to campy's
closed box tapper square design.

--
Morten Reippuert Knudsen :-) <http://blog.reippuert.dk>

Merlin Works CR-3/2.5 & Campagnolo Chorus 2007.

[jim beam]

tbaskin@mbplaw.com wrote:
> Am contemplating a build for a custom frame. UT has been around now
> since '06. What is the collective experience as to whether this
> solves a problem that exists with square taper, and represents a
> legitimate improvement?
>

cT = 0.86

for the remainder, bb choice will not influence your frame construction
in the slightest - just go ahead and order, then choose whatever crank
you want.

[landotter]

On Jan 12, 2:33 pm, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
wrote:
> tbas...@mbplaw.com aka Tom Baskin wrote:
>
> > Am contemplating a build for a custom frame. UT has been around now
> > since '06. What is the collective experience as to whether this
> > solves a problem that exists with square taper, and represents a
> > legitimate improvement?
>
> You might as well ask what the true religion is. ;)


JIS JIS JIS!!

/ululates and brandishes Kalashnikov

[still just me]

On Sat, 12 Jan 2008 14:33:49 -0600, Tom Sherman
<sunsetss0003@REMOVETHISyahoo.com> wrote:

>
>You might as well ask what the true religion is. ;)

Christianity. Just ask Huckabee.

(oh,oh, diversion!)

[It's Chris]

There's problem with square taper? Gee, I've had my cranks for 16 years
now, is there something I should know? ;-3)>

- -
Compliments of:
"Your Friendly Neighborhood Wheelman"

If you want to E-mail me use:
ChrisZCorner "at" webtv "dot" net

My website:
http://geocities.com/czcorner

[Tom Sherman]

landotter wrote:
> On Jan 12, 2:33 pm, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
> wrote:
>> tbas...@mbplaw.com aka Tom Baskin wrote:
>>
>>> Am contemplating a build for a custom frame. UT has been around now
>>> since '06. What is the collective experience as to whether this
>>> solves a problem that exists with square taper, and represents a
>>> legitimate improvement?
>> You might as well ask what the true religion is. ;)
>
>
> JIS JIS JIS!!
>
> /ululates and brandishes Kalashnikov

Greased or un-greased at installation?

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[NickK3@aol.com]

On Jan 12, 3:55*pm, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
wrote:
> landotter wrote:
> > On Jan 12, 2:33 pm, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
> > wrote:
> >> tbas...@mbplaw.com aka Tom Baskin wrote:
>
> >>> Am contemplating a build for a custom frame. *UT has been around now
> >>> since '06. *What is the collective experience as to whether this
> >>> solves a problem that exists with square taper, and represents a
> >>> legitimate improvement?
> >> You might as well ask what the true religion is. ;)
>
> > JIS JIS JIS!!
>
> > /ululates and brandishes Kalashnikov
>
> Greased or un-greased at installation?
>
> --
> Tom Sherman - Holstein-Friesland Bovinia
> "And never forget, life ultimately makes failures of all people."
> - A. Derleth

Com'on guys!
Square has worked for a long time... UT has worked for a shorter
time... I wouldn't loose too much sleep deciding between the
two........... (If they are installed right :-O !!!)

[Chalo]

Nic...@aol.com wrote:
>
> Com'on guys!
> Square has worked for a long time...

If by "worked" you mean "broken", then you would be describing my own
experiences with square taper spindles. The fact that lightweight
riders who don't ride many miles get by with them is not an indication
of their virtue; it's how they hold up when put to a real challenge.
(It turns out they have a glass jaw.)

Little children get by just fine with plastic pedals and headsets that
have no bearings, but that does not make them the equal of metal
pedals and headsets with mechanical bearings.

Chalo

[It's Chris]

From: wheeledBobNOSPAM@yahoo.com (still*just*me)

>..On Sat, 12 Jan 2008 14:33:49 -0600,
>Tom Sherman
><sunsetss0003@REMOVETHISyahoo.cm> wrote:

>>You might as well ask what the true
>>religion is. ;)

>Christianity. Just ask Huckabee.

>(oh,oh, diversion!)

S*** you've done it now. I see a 10,000 post flame thread coming!

- -
Compliments of:
"Your Friendly Neighborhood Wheelman"

If you want to E-mail me use:
ChrisZCorner "at" webtv "dot" net

My website:
http://geocities.com/czcorner

[Ozark Bicycle]

On Jan 12, 4:16*pm, Morten Reippuert Knudsen <s...@reippuert.dk>
wrote:
> tbas...@mbplaw.com wrote:
> > Am contemplating a build for a custom frame. *UT has been around now
> > since '06. *What is the collective experience as to whether this
> > solves a problem that exists with square taper
>
> witch problems?


Can't be the very low failure rate of steel square taper
spindles....wait! It must be the marketing problem of selling proven-
but-boring technology in the face of !!!new!new!new!!! from Shimano.



>
> > and represents a legitimate improvement?
>
> It way ligther. but bearring sealing is rubbish compared to campy's
> closed box tapper square design.

Picky, picky! ;-)

[David L. Johnson]

Morten Reippuert Knudsen wrote:
> tbaskin@mbplaw.com wrote:
>> Am contemplating a build for a custom frame. UT has been around now
>> since '06. What is the collective experience as to whether this
>> solves a problem that exists with square taper
>
> witch problems?

We haven't had problems with them around here in a long time.

--

David L. Johnson

Accept risk. Accept responsibility. Put a lawyer out of business.

[southphilly]

Square taper versus UT?

I doubt UT, in its currant incarnation, will be around for that long.
The Cannondale standard might take over, or some other standard that
allows the bearing races to be inside the frame. It is easy to
imagine how outboard bearings will be labled as a stop gap solution
'solved' by the larger diameter bottom bracket. Also, getting the
bearings inside the frame will allow for a lower Q-factor (whether
this is a good idea or not doesn't matter--this is another marketing
angle.)

Do deal with a similar decision I went with, gasp, ISIS. Had a square
taper crank been an option I might very well have chosen that
instead. I decided that in four years there will be new standard.
Between my box full of octalink and SKF ISIS bottom brackets I hope to
skip at least the outboard bearing crank experiement. I bet square
taper campy BB will be around for a long time, and in ten years will
be at least as easy to get as UT because UT will be abandoned.

[John Forrest Tomlinson]

On Sat, 12 Jan 2008 16:46:05 -0800 (PST), Chalo
<chalo.colina@gmail.com> wrote:

>The fact that lightweight
>riders who don't ride many miles get by with them is not an indication
>of their virtue; it's how they hold up when put to a real challenge.

You mean, average riders who put average to high mileage don't have
any problem with them....

[jobst.brandt@stanfordalumni.org]

The square taper went out of style because many riders who maintained
their own bicycles did not understand that torque for a proper press
fit needed to be about 26.5ft-lb, and therefore, often under-tightened
them using the 6" long Campagnolo peanut butter wrench (bikies made
peanut butter sandwiches using the handle). That means 53lb force on
a six inch lever, more than most people believe is required.

Subsequently, cranks were damaged by backlash in the taper and loss of
the retaining bolt, because the lock nut (aka dust cover) was not used
being unnecessary rotating mass. Once operated loose a crank is
ruined and no amount of bolt tension can fix that.

In response, someone unclear on the subject of press fits came out
with advice to not use grease on the taper because greased, it could
not transmit pedaling torque. A press fit can only be accurately
specified with all parts lubricated, bolt, washer, and spindle because
contact pressure is what transmits torque, not friction. However,
friction of a dry press fit will cause metal shear and friction
welding if the parts are truly clean.

When the square taper was still king, we read about failed cranks
often. The square taper in the hands of a skilled mechanic is
foolproof and durable but the market is not made of such bicyclists.

--
Jobst Brandt

[It's Chris]

From: chalo.colina@gmail.com (Chalo)

>The fact that lightweight riders who don't
>ride many miles get by with them is not
>an indication of their virtue; it's how they
>hold up when put to a real challenge. (It
>turns out they have a glass jaw.)

"Lightweights"? You mean like Eddy Merckx, Fousto Coppi? Bernard
Hinoult? Those lightweights?

- -
Compliments of:
"Your Friendly Neighborhood Wheelman"

If you want to E-mail me use:
ChrisZCorner "at" webtv "dot" net

My website:
http://geocities.com/czcorner

[Chalo]

On Jan 12, 7:42 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Sat, 12 Jan 2008 16:46:05 -0800 (PST), Chalo
>
> <chalo.col...@gmail.com> wrote:
> >The fact that lightweight
> >riders who don't ride many miles get by with them is not an indication
> >of their virtue; it's how they hold up when put to a real challenge.
>
> You mean, average riders who put average to high mileage don't have
> any problem with them....

--Other then chronic loosening, with permanent damage to the left
crankarm as a result. And cumulative wear and chainline drift from
repeated removal and reinstallation. And the necessity of having a
whole special set of tools to deal with them.

Yeah, other than those things, average riders have very few problems
with them. But big, strong, or very high mileage riders break them.

By any chance, do you like English cars?

Chalo

[jim beam]

jobst.brandt@stanfordalumni.org wrote:
> The square taper went out of style because many riders who maintained
> their own bicycles did not understand that torque for a proper press
> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
> them using the 6" long Campagnolo peanut butter wrench (bikies made
> peanut butter sandwiches using the handle). That means 53lb force on
> a six inch lever, more than most people believe is required.
>
> Subsequently, cranks were damaged by backlash in the taper and loss of
> the retaining bolt, because the lock nut (aka dust cover) was not used
> being unnecessary rotating mass. Once operated loose a crank is
> ruined and no amount of bolt tension can fix that.
>
> In response, someone unclear on the subject of press fits came out
> with advice to not use grease on the taper because greased, it could
> not transmit pedaling torque. A press fit can only be accurately
> specified with all parts lubricated, bolt, washer, and spindle because
> contact pressure is what transmits torque, not friction. However,
> friction of a dry press fit will cause metal shear and friction
> welding if the parts are truly clean.
>
> When the square taper was still king, we read about failed cranks
> often. The square taper in the hands of a skilled mechanic is
> foolproof

foolproof? like this kind of foolproof?

http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg

proof of a fool more like.


> and durable but the market is not made of such bicyclists.
>

see above.

[Michael Baldwin]

>When the square taper was still king, we read about
>failed cranks often. The square taper in the hands of
>a skilled mechanic is foolproof and durable but the market
>is not made of such bicyclists.
>--
>Jobst Brandt

...I've reviewed Mr. Beam's attached photos of failures...my own
experience says 3 of the 4 failures are related to over tightened crank
bolts...there are other variables involved as well (stack-ups)...

Best Regards - Mike Baldwin

[Brian Huntley]

On Jan 12, 9:43 pm, jim beam <spamvor...@bad.example.net> wrote:
> jobst.bra...@stanfordalumni.org wrote:
> > When the square taper was still king, we read about failed cranks
> > often. The square taper in the hands of a skilled mechanic is
> > foolproof
>
> foolproof? like this kind of foolproof?
>

I'm curious - what makes that second one (http://pardo.net/bike/pic/
fail-001/spindle-fail-001.jpg) a square-taper related failure? It's
the middle of the BB axle.

Is there some edge-related stress propagation or something?

[Ozark Bicycle]

On Jan 12, 8:43*pm, jim beam <spamvor...@bad.example.net> wrote:
> jobst.bra...@stanfordalumni.org wrote:
> > The square taper went out of style because many riders who maintained
> > their own bicycles did not understand that torque for a proper press
> > fit needed to be about 26.5ft-lb, and therefore, often under-tightened
> > them using the 6" long Campagnolo peanut butter wrench (bikies made
> > peanut butter sandwiches using the handle). *That means 53lb force on
> > a six inch lever, more than most people believe is required.
>
> > Subsequently, cranks were damaged by backlash in the taper and loss of
> > the retaining bolt, because the lock nut (aka dust cover) was not used
> > being unnecessary rotating mass. *Once operated loose a crank is
> > ruined and no amount of bolt tension can fix that.
>
> > In response, someone unclear on the subject of press fits came out
> > with advice to not use grease on the taper because greased, it could
> > not transmit pedaling torque. *A press fit can only be accurately
> > specified with all parts lubricated, bolt, washer, and spindle because
> > contact pressure is what transmits torque, not friction. *However,
> > friction of a dry press fit will cause metal shear and friction
> > welding if the parts are truly clean.
>
> > When the square taper was still king, we read about failed cranks
> > often. *The square taper in the hands of a skilled mechanic is
> > foolproof
>
> foolproof? *like this kind of foolproof?
>
> http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG

Not a good example, as the Viscount spindle differed from 'standard'
square taper design and was notoroious for it's failure rate.

>http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg

Not really a failure of the square taper interface, is it?

>http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
>http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
>http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg

And, let's remember that square taper had, and still has, a huge
installed base. I wonder what the failure rate is v. Octalink and/or
ISIS.

[jim beam]

jim beam wrote:
> jobst.brandt@stanfordalumni.org wrote:
>> The square taper went out of style because many riders who maintained
>> their own bicycles did not understand that torque for a proper press
>> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
>> them using the 6" long Campagnolo peanut butter wrench (bikies made
>> peanut butter sandwiches using the handle). That means 53lb force on
>> a six inch lever, more than most people believe is required.
>>
>> Subsequently, cranks were damaged by backlash in the taper and loss of
>> the retaining bolt, because the lock nut (aka dust cover) was not used
>> being unnecessary rotating mass. Once operated loose a crank is
>> ruined and no amount of bolt tension can fix that.
>>
>> In response, someone unclear on the subject of press fits came out
>> with advice to not use grease on the taper because greased, it could
>> not transmit pedaling torque. A press fit can only be accurately
>> specified with all parts lubricated, bolt, washer, and spindle because
>> contact pressure is what transmits torque, not friction. However,
>> friction of a dry press fit will cause metal shear and friction
>> welding if the parts are truly clean.
>>
>> When the square taper was still king, we read about failed cranks
>> often. The square taper in the hands of a skilled mechanic is
>> foolproof
>
> foolproof? like this kind of foolproof?
>

follow-up for those interested in understanding more about the failures
[within limits of what we can tell from these pics]...


> http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG

as stated by others, the circlip groove is a stress riser and can
initiate fatigue. however, in this case, the crack seems to start at
the bearing interface inside of the groove - which would in fact be a
more common failure point on un-grooved shafts. either way, poor
material, narrow spindle, not adequate for high fatigue.

> http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg

torsion fatigue - almost certainly initiated by one of the stampings.

> http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg

appears to start at the point where the flats of the taper come to an
end. probably too small a radius in the machining.

> http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg

as above.

> http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg

as above.


>
> proof of a fool more like.
>
>
>> and durable but the market is not made of such bicyclists.
>>
>
> see above.

[jim beam]

Brian Huntley wrote:
> On Jan 12, 9:43 pm, jim beam <spamvor...@bad.example.net> wrote:
>> jobst.bra...@stanfordalumni.org wrote:
>>> When the square taper was still king, we read about failed cranks
>>> often. The square taper in the hands of a skilled mechanic is
>>> foolproof
>> foolproof? like this kind of foolproof?
>>
>
> I'm curious - what makes that second one (http://pardo.net/bike/pic/
> fail-001/spindle-fail-001.jpg) a square-taper related failure? It's
> the middle of the BB axle.
>
> Is there some edge-related stress propagation or something?

smaller diameter means more surface stress and therefore greater fatigue
susceptibility. big pipe spindles are stiffer, lighter, and
correspondingly less susceptible to these kinds of failures.

[Ryan Cousineau]

In article
<785dab45-4385-49d3-9867-34a45b2d4f1b@n20g2000hsh.googlegroups.com>,
Brian Huntley <brian_huntley@hotmail.com> wrote:

> On Jan 12, 9:43 pm, jim beam <spamvor...@bad.example.net> wrote:
> > jobst.bra...@stanfordalumni.org wrote:
> > > When the square taper was still king, we read about failed cranks
> > > often. The square taper in the hands of a skilled mechanic is
> > > foolproof
> >
> > foolproof? like this kind of foolproof?
> >
>
> I'm curious - what makes that second one (http://pardo.net/bike/pic/
> fail-001/spindle-fail-001.jpg) a square-taper related failure? It's
> the middle of the BB axle.
>
> Is there some edge-related stress propagation or something?

More that square tapers are limited in their spindle dimensions by the
bearing diameter, more or less.

external-bearing designs (and oversize BBs) allow larger-diameter
spindles.

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"My scenarios may give the impression I could be an excellent crook.
Not true - I am a talented lawyer." - Sandy in rec.bicycles.racing

[It's Chris]

From: spamvortex@bad.example.net (jim*beam)

>Big pipe spindles are stiffer, lighter, and
>correspondingly less susceptible to these
>kinds of failures.

Seriously, just how much bigger than Sq. taper ARE the UT spindles?
Maybe we should all swap out our narrow spindles for three inch diameter
Uber spindles

- -
Compliments of:
"Your Friendly Neighborhood Wheelman"

If you want to E-mail me use:
ChrisZCorner "at" webtv "dot" net

My website:
http://geocities.com/czcorner

[landotter]

On Jan 12, 9:37 pm, Ozark Bicycle
<bicycleatel...@ozarkbicycleservice.com> wrote:
> On Jan 12, 8:43 pm, jim beam <spamvor...@bad.example.net> wrote:
>
>
>
> > jobst.bra...@stanfordalumni.org wrote:
> > > The square taper went out of style because many riders who maintained
> > > their own bicycles did not understand that torque for a proper press
> > > fit needed to be about 26.5ft-lb, and therefore, often under-tightened
> > > them using the 6" long Campagnolo peanut butter wrench (bikies made
> > > peanut butter sandwiches using the handle). That means 53lb force on
> > > a six inch lever, more than most people believe is required.
>
> > > Subsequently, cranks were damaged by backlash in the taper and loss of
> > > the retaining bolt, because the lock nut (aka dust cover) was not used
> > > being unnecessary rotating mass. Once operated loose a crank is
> > > ruined and no amount of bolt tension can fix that.
>
> > > In response, someone unclear on the subject of press fits came out
> > > with advice to not use grease on the taper because greased, it could
> > > not transmit pedaling torque. A press fit can only be accurately
> > > specified with all parts lubricated, bolt, washer, and spindle because
> > > contact pressure is what transmits torque, not friction. However,
> > > friction of a dry press fit will cause metal shear and friction
> > > welding if the parts are truly clean.
>
> > > When the square taper was still king, we read about failed cranks
> > > often. The square taper in the hands of a skilled mechanic is
> > > foolproof
>
> > foolproof? like this kind of foolproof?
>
> >http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>
> Not a good example, as the Viscount spindle differed from 'standard'
> square taper design and was notoroious for it's failure rate.

Mine was replaced with a sturdy Campy one when I bought it, looked
like ti? Who knows. problem with the original Viscount spindles was
the circlip groove, AFAIK.

>
> >http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>
> Not really a failure of the square taper interface, is it?
>
> >http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
> >http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
> >http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>
> And, let's remember that square taper had, and still has, a huge
> installed base. I wonder what the failure rate is v. Octalink and/or
> ISIS.

One can google image search and find failures of anything. That said,
I'm a square taper fan because for most riders it's trouble free when
torqued down well, and you're not trying to use a stupid light hollow
spindle. Outboard splined BBs may be worth a shot with heavier or
harder riders. Spindle failure certainly is more dire than crummy
bearings.

[jim beam]

Ozark Bicycle wrote:
> On Jan 12, 8:43�pm, jim beam <spamvor...@bad.example.net> wrote:
>> jobst.bra...@stanfordalumni.org wrote:
>>> The square taper went out of style because many riders who maintained
>>> their own bicycles did not understand that torque for a proper press
>>> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
>>> them using the 6" long Campagnolo peanut butter wrench (bikies made
>>> peanut butter sandwiches using the handle). �That means 53lb force on
>>> a six inch lever, more than most people believe is required.
>>> Subsequently, cranks were damaged by backlash in the taper and loss of
>>> the retaining bolt, because the lock nut (aka dust cover) was not used
>>> being unnecessary rotating mass. �Once operated loose a crank is
>>> ruined and no amount of bolt tension can fix that.
>>> In response, someone unclear on the subject of press fits came out
>>> with advice to not use grease on the taper because greased, it could
>>> not transmit pedaling torque. �A press fit can only be accurately
>>> specified with all parts lubricated, bolt, washer, and spindle because
>>> contact pressure is what transmits torque, not friction. �However,
>>> friction of a dry press fit will cause metal shear and friction
>>> welding if the parts are truly clean.
>>> When the square taper was still king, we read about failed cranks
>>> often. �The square taper in the hands of a skilled mechanic is
>>> foolproof
>> foolproof? �like this kind of foolproof?
>>
>> http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>
> Not a good example, as the Viscount spindle differed from 'standard'
> square taper design and was notoroious for it's failure rate.
>
>> http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>
> Not really a failure of the square taper interface, is it?
>
>> http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
>> http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
>> http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>
> And, let's remember that square taper had, and still has, a huge
> installed base. I wonder what the failure rate is v. Octalink and/or
> ISIS.
>

two things:

1. don't get bamboozled by jobstian bull**** about the benefits of
"square taper" when it's married to a fundamentally inferior [small
diameter] spindle.

2. square taper is itself an unreliable interface - in that it is highly
intolerant of typical "bike shop" fitting variance.

on that last point, jobst's torque spec of "about 26.5ft-lb" is
ridiculous. any idea how much it costs to get three digit torque
resolution? [hint: more then the value of the bike.]

[Ozark Bicycle]

On Jan 12, 9:54*pm, landotter <landot...@gmail.com> wrote:
> On Jan 12, 9:37 pm, Ozark Bicycle
>
>
>
> <bicycleatel...@ozarkbicycleservice.com> wrote:
> > On Jan 12, 8:43 pm, jim beam <spamvor...@bad.example.net> wrote:
>
> > > jobst.bra...@stanfordalumni.org wrote:
> > > > The square taper went out of style because many riders who maintained
> > > > their own bicycles did not understand that torque for a proper press
> > > > fit needed to be about 26.5ft-lb, and therefore, often under-tightened
> > > > them using the 6" long Campagnolo peanut butter wrench (bikies made
> > > > peanut butter sandwiches using the handle). *That means 53lb force on
> > > > a six inch lever, more than most people believe is required.
>
> > > > Subsequently, cranks were damaged by backlash in the taper and loss of
> > > > the retaining bolt, because the lock nut (aka dust cover) was not used
> > > > being unnecessary rotating mass. *Once operated loose a crank is
> > > > ruined and no amount of bolt tension can fix that.
>
> > > > In response, someone unclear on the subject of press fits came out
> > > > with advice to not use grease on the taper because greased, it could
> > > > not transmit pedaling torque. *A press fit can only be accurately
> > > > specified with all parts lubricated, bolt, washer, and spindle because
> > > > contact pressure is what transmits torque, not friction. *However,
> > > > friction of a dry press fit will cause metal shear and friction
> > > > welding if the parts are truly clean.
>
> > > > When the square taper was still king, we read about failed cranks
> > > > often. *The square taper in the hands of a skilled mechanic is
> > > > foolproof
>
> > > foolproof? *like this kind of foolproof?
>
> > >http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>
> > Not a good example, as the Viscount spindle differed from 'standard'
> > square taper design and was notoroious for it's failure rate.
>
> Mine was replaced with a sturdy Campy one when I bought it, looked
> like ti? Who knows. problem with the original Viscount spindles was
> the circlip groove, AFAIK.

Correct, and that is where the Viscount spindle in the linked pic
failed.
>
>
>
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>
> > Not really a failure of the square taper interface, is it?
>
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>
> > And, let's remember that square taper had, and still has, a huge
> > installed base. I wonder what the failure rate is v. Octalink and/or
> > ISIS.
>
> One can google image search and find failures of anything.

Especially a component that has such a large installed base and one
that was virtually "the only game in town" on high quality bikes for
many years.


> That said,
> I'm a square taper fan because for most riders it's trouble free when
> torqued down well, and you're not trying to use a stupid light hollow
> spindle. Outboard splined BBs may be worth a shot with heavier or
> harder riders. Spindle failure certainly is more dire than crummy
> bearings.

[Tim McNamara]

In article
<eaebdd7c-cfb5-4874-9285-74e32804e3d4@f3g2000hsg.googlegroups.com>,
landotter <landotter@gmail.com> wrote:

> On Jan 12, 9:37 pm, Ozark Bicycle
> <bicycleatel...@ozarkbicycleservice.com> wrote:
> > On Jan 12, 8:43 pm, jim beam <spamvor...@bad.example.net> wrote:
> >
> >
> >
> > > jobst.bra...@stanfordalumni.org wrote:
> > > > The square taper went out of style because many riders who
> > > > maintained their own bicycles did not understand that torque
> > > > for a proper press fit needed to be about 26.5ft-lb, and
> > > > therefore, often under-tightened them using the 6" long
> > > > Campagnolo peanut butter wrench (bikies made peanut butter
> > > > sandwiches using the handle). That means 53lb force on a six
> > > > inch lever, more than most people believe is required.
> >
> > > > Subsequently, cranks were damaged by backlash in the taper and
> > > > loss of the retaining bolt, because the lock nut (aka dust
> > > > cover) was not used being unnecessary rotating mass. Once
> > > > operated loose a crank is ruined and no amount of bolt tension
> > > > can fix that.
> >
> > > > In response, someone unclear on the subject of press fits came
> > > > out with advice to not use grease on the taper because greased,
> > > > it could not transmit pedaling torque. A press fit can only be
> > > > accurately specified with all parts lubricated, bolt, washer,
> > > > and spindle because contact pressure is what transmits torque,
> > > > not friction. However, friction of a dry press fit will cause
> > > > metal shear and friction welding if the parts are truly clean.
> >
> > > > When the square taper was still king, we read about failed
> > > > cranks often. The square taper in the hands of a skilled
> > > > mechanic is foolproof
> >
> > > foolproof? like this kind of foolproof?
> >
> > >http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
> >
> > Not a good example, as the Viscount spindle differed from
> > 'standard' square taper design and was notoroious for it's failure
> > rate.
>
> Mine was replaced with a sturdy Campy one when I bought it, looked
> like ti? Who knows. problem with the original Viscount spindles was
> the circlip groove, AFAIK.

Right. The circlip groove was the source of the fracture of a Viscount
BB axle in my own experience, and there are multiple examples of that
failure. Between that and the cast aluminum fork separating from the
steel steerer tube, the Viscount was a seriously flawed bike.

> > >http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
> >
> > Not really a failure of the square taper interface, is it?
> >
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
> > >http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
> >
> > And, let's remember that square taper had, and still has, a huge
> > installed base. I wonder what the failure rate is v. Octalink
> > and/or ISIS.
>
> One can google image search and find failures of anything. That said,
> I'm a square taper fan because for most riders it's trouble free when
> torqued down well, and you're not trying to use a stupid light hollow
> spindle. Outboard splined BBs may be worth a shot with heavier or
> harder riders. Spindle failure certainly is more dire than crummy
> bearings.

From personal experience I would agree. Bearing failures have never
dumped me into the street into the line of traffic, but breaking a BB
axle has. Cracking the crank at the square taper hole is less likely to
be dangerous than breaking the BB axle, since the crank is likely to be
retained by the bolt.

[Tom Sherman]

David L. Johnson wrote:
> Morten Reippuert Knudsen wrote:
>> tbaskin@mbplaw.com wrote:
>>> Am contemplating a build for a custom frame. UT has been around now
>>> since '06. What is the collective experience as to whether this
>>> solves a problem that exists with square taper
>>
>> witch problems?
>
> We haven't had problems with them around here in a long time.
>
Because you burned them all?

"If... she... weighs... the same as a duck,... she's made of wood." -
Villager

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[Morten Reippuert Knudsen]

David L. Johnson <david.johnson@lehigh.edu> wrote:
> Morten Reippuert Knudsen wrote:
>> tbaskin@mbplaw.com wrote:
>>> Am contemplating a build for a custom frame. UT has been around now
>>> since '06. What is the collective experience as to whether this
>>> solves a problem that exists with square taper
>>
>> witch problems?
>
> We haven't had problems with them around here in a long time.

just my point: there are no problems with tapper square.

--
Morten Reippuert Knudsen :-) <http://blog.reippuert.dk>

Merlin Works CR-3/2.5 & Campagnolo Chorus 2007.

[carlfogel@comcast.net]

On Sat, 12 Jan 2008 20:04:32 -0800, jim beam
<spamvortex@bad.example.net> wrote:

>on that last point, jobst's torque spec of "about 26.5ft-lb" is
>ridiculous. any idea how much it costs to get three digit torque
>resolution? [hint: more then the value of the bike.]

Dear Jim,

Fortunately, getting ~36 newton-meters is much less expensive:
http://www.onlineconversion.com/torque.htm

Cheers,

Carl Fogel

[Ozark Bicycle]

On Jan 12, 10:04Â*pm, jim beam <spamvor...@bad.example.net> wrote:
> Ozark Bicycle wrote:
> > On Jan 12, 8:43�pm, jim beam <spamvor...@bad.example.net> wrote:
> >> jobst.bra...@stanfordalumni.org wrote:
> >>> The square taper went out of style because many riders who maintained
> >>> their own bicycles did not understand that torque for a proper press
> >>> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
> >>> them using the 6" long Campagnolo peanut butter wrench (bikies made
> >>> peanut butter sandwiches using the handle). �That means 53lb force on
> >>> a six inch lever, more than most people believe is required.
> >>> Subsequently, cranks were damaged by backlash in the taper and loss of
> >>> the retaining bolt, because the lock nut (aka dust cover) was not used
> >>> being unnecessary rotating mass. �Once operated loose a crank is
> >>> ruined and no amount of bolt tension can fix that.
> >>> In response, someone unclear on the subject of press fits came out
> >>> with advice to not use grease on the taper because greased, it could
> >>> not transmit pedaling torque. �A press fit can only be accurately
> >>> specified with all parts lubricated, bolt, washer, and spindle because
> >>> contact pressure is what transmits torque, not friction. �However,
> >>> friction of a dry press fit will cause metal shear and friction
> >>> welding if the parts are truly clean.
> >>> When the square taper was still king, we read about failed cranks
> >>> often. �The square taper in the hands of a skilled mechanic is
> >>> foolproof
> >> foolproof? �like this kind of foolproof?
>
> >>http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>
> > Not a good example, as the Viscount spindle differed from 'standard'
> > square taper design and was notoroious for it's failure rate.
>
> >>http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>
> > Not really a failure of the square taper interface, is it?
>
> >>http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
> >>http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
> >>http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>
> > And, let's remember that square taper had, and still has, a huge
> > installed base. I wonder what the failure rate is v. Octalink and/or
> > ISIS.
>
> two things:
>
> 1. don't get bamboozled by jobstian bull**** about the benefits of
> "square taper" when it's married to a fundamentally inferior [small
> diameter] spindle.

My favorable opinion of square taper is the result of experience, not
a blast of bluster coming out of Palo Alto. :-)

Seriously, IME, decent quality square taper spindles have a very low
failure rate. I remain of the opinion that, for recreational riders,
"new" designs such as Octalink, ISIS and the now various "external
bearing" designs offer no discernable advantage and are, in fact,
purely marketing driven. YMMV.

>
> 2. square taper is itself an unreliable interface - in that it is highly
> intolerant of typical "bike shop" fitting variance.

Sure, there is no accounting for ham-fisted bozos using the "brute
strength and ignorance" method. Of course, the new "external bearing"
designs are much more sensitive to BB shell prep than any cartridge BB
(square taper, Octalink or ISIS). How many shops prep BB shells these
days?


>
> on that last point, jobst's torque spec of "about 26.5ft-lb" is
> ridiculous. Â*any idea how much it costs to get three digit torque
> resolution? Â*[hint: more then the value of the bike.]

But it's so typically Brandt, isn't it? ("baffle 'em with bull****")

[jim beam]

Ozark Bicycle wrote:
> On Jan 12, 9:54�pm, landotter <landot...@gmail.com> wrote:
>> On Jan 12, 9:37 pm, Ozark Bicycle
>>
>>
>>
>> <bicycleatel...@ozarkbicycleservice.com> wrote:
>>> On Jan 12, 8:43 pm, jim beam <spamvor...@bad.example.net> wrote:
>>>> jobst.bra...@stanfordalumni.org wrote:
>>>>> The square taper went out of style because many riders who maintained
>>>>> their own bicycles did not understand that torque for a proper press
>>>>> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
>>>>> them using the 6" long Campagnolo peanut butter wrench (bikies made
>>>>> peanut butter sandwiches using the handle). �That means 53lb force on
>>>>> a six inch lever, more than most people believe is required.
>>>>> Subsequently, cranks were damaged by backlash in the taper and loss of
>>>>> the retaining bolt, because the lock nut (aka dust cover) was not used
>>>>> being unnecessary rotating mass. �Once operated loose a crank is
>>>>> ruined and no amount of bolt tension can fix that.
>>>>> In response, someone unclear on the subject of press fits came out
>>>>> with advice to not use grease on the taper because greased, it could
>>>>> not transmit pedaling torque. �A press fit can only be accurately
>>>>> specified with all parts lubricated, bolt, washer, and spindle because
>>>>> contact pressure is what transmits torque, not friction. �However,
>>>>> friction of a dry press fit will cause metal shear and friction
>>>>> welding if the parts are truly clean.
>>>>> When the square taper was still king, we read about failed cranks
>>>>> often. �The square taper in the hands of a skilled mechanic is
>>>>> foolproof
>>>> foolproof? �like this kind of foolproof?
>>>> http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>>> Not a good example, as the Viscount spindle differed from 'standard'
>>> square taper design and was notoroious for it's failure rate.
>> Mine was replaced with a sturdy Campy one when I bought it, looked
>> like ti? Who knows. problem with the original Viscount spindles was
>> the circlip groove, AFAIK.
>
> Correct, and that is where the Viscount spindle in the linked pic
> failed.
>>
>>
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>>> Not really a failure of the square taper interface, is it?
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>>> And, let's remember that square taper had, and still has, a huge
>>> installed base. I wonder what the failure rate is v. Octalink and/or
>>> ISIS.
>> One can google image search and find failures of anything.
>
> Especially a component that has such a large installed base and one
> that was virtually "the only game in town" on high quality bikes for
> many years.

where are all the octalink failures?


>
>
>> That said,
>> I'm a square taper fan because for most riders it's trouble free when
>> torqued down well, and you're not trying to use a stupid light hollow
>> spindle. Outboard splined BBs may be worth a shot with heavier or
>> harder riders. Spindle failure certainly is more dire than crummy
>> bearings.
>

[Rex Kerr]

jim beam wrote:
> where are all the octalink failures?

I've had one (the only BB/crank interface failure that I've ever had),
while on tour. I had to basically pedal with one foot and walk up hills
for a good 30 miles to get to the nearest LBS.

[Chalo]

Ozark Bicycle wrote:
>
> Seriously, IME, decent quality square taper spindles have a very low
> failure rate. I remain of the opinion that, for recreational riders,
> "new" designs such as Octalink, ISIS and the now various "external
> bearing" designs offer no discernable advantage and are, in fact,
> purely marketing driven. YMMV.

By "recreational riders", might you mean people who don't ride hard,
far, or often? Because such riders seem to do well with the square
taper-- they don't overstress it and they don't have to remove and
replace it much more often than they "upgrade" to new bikes.

Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
marketing-driven standards, but those are not the only games in town.
OPC is a fine and reliable standard, as are the various 48-spline
interference fitted interfaces, and the various 8- to 12-spline pinch-
bolted interfaces, and the non-tapered square and hex pinch-bolted
interfaces used in high quality BMX cranks. All of them display
superior serviceability, longevity, and safety compared to the square
taper.

Chalo

[jim beam]

Ozark Bicycle wrote:
> On Jan 12, 10:04 pm, jim beam <spamvor...@bad.example.net> wrote:
>> Ozark Bicycle wrote:
>>> On Jan 12, 8:43�pm, jim beam <spamvor...@bad.example.net> wrote:
>>>> jobst.bra...@stanfordalumni.org wrote:
>>>>> The square taper went out of style because many riders who maintained
>>>>> their own bicycles did not understand that torque for a proper press
>>>>> fit needed to be about 26.5ft-lb, and therefore, often under-tightened
>>>>> them using the 6" long Campagnolo peanut butter wrench (bikies made
>>>>> peanut butter sandwiches using the handle). �That means 53lb force on
>>>>> a six inch lever, more than most people believe is required.
>>>>> Subsequently, cranks were damaged by backlash in the taper and loss of
>>>>> the retaining bolt, because the lock nut (aka dust cover) was not used
>>>>> being unnecessary rotating mass. �Once operated loose a crank is
>>>>> ruined and no amount of bolt tension can fix that.
>>>>> In response, someone unclear on the subject of press fits came out
>>>>> with advice to not use grease on the taper because greased, it could
>>>>> not transmit pedaling torque. �A press fit can only be accurately
>>>>> specified with all parts lubricated, bolt, washer, and spindle because
>>>>> contact pressure is what transmits torque, not friction. �However,
>>>>> friction of a dry press fit will cause metal shear and friction
>>>>> welding if the parts are truly clean.
>>>>> When the square taper was still king, we read about failed cranks
>>>>> often. �The square taper in the hands of a skilled mechanic is
>>>>> foolproof
>>>> foolproof? �like this kind of foolproof?
>>>> http://pardo.net/bike/pic/fail-001/bbViscountAx2.JPG
>>> Not a good example, as the Viscount spindle differed from 'standard'
>>> square taper design and was notoroious for it's failure rate.
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-001.jpg
>>> Not really a failure of the square taper interface, is it?
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-002.jpg
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-003.jpg
>>>> http://pardo.net/bike/pic/fail-001/spindle-fail-004.jpg
>>> And, let's remember that square taper had, and still has, a huge
>>> installed base. I wonder what the failure rate is v. Octalink and/or
>>> ISIS.
>> two things:
>>
>> 1. don't get bamboozled by jobstian bull**** about the benefits of
>> "square taper" when it's married to a fundamentally inferior [small
>> diameter] spindle.
>
> My favorable opinion of square taper is the result of experience, not
> a blast of bluster coming out of Palo Alto. :-)
>
> Seriously, IME, decent quality square taper spindles have a very low
> failure rate.

indeed. but they are still subject to higher stress just due to their
physical dimensions. failure can be mitigated with high quality
materials and attention to detail, but that costs more. it's like
spokes where the traditional j-bend design is fundamentally problematic,
so again, the "solution" is more expensive materials.



> I remain of the opinion that, for recreational riders,
> "new" designs such as Octalink, ISIS and the now various "external
> bearing" designs offer no discernable advantage and are, in fact,
> purely marketing driven. YMMV.

my mileage varies. as a big guy, the difference between traditional
crank and octalink when standing on the hills is most definitely
noticeable - the big pipe is stiffer. if you look at the math, you'll
see it's no marketing gimmick. stiffness for stiffness, big hollow pipe
is lighter too.


>
>> 2. square taper is itself an unreliable interface - in that it is highly
>> intolerant of typical "bike shop" fitting variance.
>
> Sure, there is no accounting for ham-fisted bozos using the "brute
> strength and ignorance" method. Of course, the new "external bearing"
> designs are much more sensitive to BB shell prep than any cartridge BB
> (square taper, Octalink or ISIS). How many shops prep BB shells these
> days?

how many did before?

personally, i like the cartridge designs for this reason. shimano
square taper bb's are [generally] very high quality and very reliable,
but octalink is better. some of the external bearing designs are
problematic in that the bearing interface is not interference, and the
axle tube wall is thin enough to have elastic distortion problems, so
i'm sitting back and watching those designs continue to evolve while i
continue to enjoy octalink reliability.


>
>
>> on that last point, jobst's torque spec of "about 26.5ft-lb" is
>> ridiculous. any idea how much it costs to get three digit torque
>> resolution? [hint: more then the value of the bike.]
>
> But it's so typically Brandt, isn't it? ("baffle 'em with bull****")
>

[John Forrest Tomlinson]

On Sat, 12 Jan 2008 20:42:18 -0800 (PST), Chalo
<chalo.colina@gmail.com> wrote:

>On Jan 12, 7:42 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
>wrote:
>> On Sat, 12 Jan 2008 16:46:05 -0800 (PST), Chalo
>>
>> <chalo.col...@gmail.com> wrote:
>> >The fact that lightweight
>> >riders who don't ride many miles get by with them is not an indication
>> >of their virtue; it's how they hold up when put to a real challenge.
>>
>> You mean, average riders who put average to high mileage don't have
>> any problem with them....
>
>--Other then chronic loosening, with permanent damage to the left
>crankarm as a result. And cumulative wear and chainline drift from
>repeated removal and reinstallation. And the necessity of having a
>whole special set of tools to deal with them.
>
>Yeah, other than those things, average riders have very few problems
>with them. But big, strong, or very high mileage riders break them.
>
>By any chance, do you like English cars?

I don't know anything about cars - have owned an American car and a
couple Japenese ones.

[Tom Sherman]

Chalo Colina wrote:
> ...
> By any chance, do you like English cars?

All the parts that fell off my MG were of the finest English quality!

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[Tim McNamara]

In article
<9d9c7150-30fb-47c8-bd0c-9a83b508b73d@e4g2000hsg.googlegroups.com>,
Chalo <chalo.colina@gmail.com> wrote:

> On Jan 12, 7:42 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
> wrote:
> > On Sat, 12 Jan 2008 16:46:05 -0800 (PST), Chalo
> >
> > <chalo.col...@gmail.com> wrote:
> > >The fact that lightweight riders who don't ride many miles get by
> > >with them is not an indication of their virtue; it's how they hold
> > >up when put to a real challenge.
> >
> > You mean, average riders who put average to high mileage don't have
> > any problem with them....
>
> --Other then chronic loosening, with permanent damage to the left
> crankarm as a result. And cumulative wear and chainline drift from
> repeated removal and reinstallation. And the necessity of having a
> whole special set of tools to deal with them.
>
> Yeah, other than those things, average riders have very few problems
> with them. But big, strong, or very high mileage riders break them.

While not quite in your category (I am 6'4" 210 lbs and ride 6,000 or so
miles a year) I think I qualify as a "big, strong and/or high mileage"
rider. I've never had one of these failures. The only square taper
failure I have had was on my old Viscount, on which the BB axle snapped
at the circlip groove after 8 years of service. I rode fewer miles in
those days but on much hillier roads that are usually available to me
now.

The crank on the bike I ride most was purchased in 1994 (old Ritchey
cold forged 110/74 square taper). I have a couple of these on different
bvikes and use them with two rings and a Campy Veloce 116 mm BB to
obtain a "Q factor" of 140 mm. Properly installed I have found this to
be a very durable design. While I am not creating the kinds of loading
you are, given that you are much taller and heavier than I am, I do load
the equipment more than the "average" person (5'10" and 175 lbs or so).

[A Muzi]

>> Chalo <chalo.col...@gmail.com> wrote:
>>> The fact that lightweight
>>> riders who don't ride many miles get by with them is not an indication
>>> of their virtue; it's how they hold up when put to a real challenge.

> John Forrest Tomlinson <usenetrem...@jt10000.com>wrote:
>> You mean, average riders who put average to high mileage don't have
>> any problem with them....

Chalo wrote:
> --Other then chronic loosening, with permanent damage to the left
> crankarm as a result. And cumulative wear and chainline drift from
> repeated removal and reinstallation. And the necessity of having a
> whole special set of tools to deal with them.
> Yeah, other than those things, average riders have very few problems
> with them. But big, strong, or very high mileage riders break them.
> By any chance, do you like English cars?

How could one _not_ love classic British cars?? so cute and, well, lovable!

[flip side: 'lovable'. Sure, it always ends badly but, hey, love is
blind. enjoy the ride!]
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[Luke]

In article
<9d9c7150-30fb-47c8-bd0c-9a83b508b73d@e4g2000hsg.googlegroups.com>,
Chalo <chalo.colina@gmail.com> wrote:

> On Jan 12, 7:42 pm, John Forrest Tomlinson <usenetrem...@jt10000.com>
> wrote:
> > On Sat, 12 Jan 2008 16:46:05 -0800 (PST), Chalo
> >
> > <chalo.col...@gmail.com> wrote:
> > >The fact that lightweight
> > >riders who don't ride many miles get by with them is not an indication
> > >of their virtue; it's how they hold up when put to a real challenge.
> >
> > You mean, average riders who put average to high mileage don't have
> > any problem with them....
>
> --Other then chronic loosening, with permanent damage to the left
> crankarm as a result. And cumulative wear and chainline drift from
> repeated removal and reinstallation. And the necessity of having a
> whole special set of tools to deal with them.

At 75 KG, 178cm, I log about 10 - 15 thousand KM/year on square taper
BBs I acknowledge the limitations/deficiencies of the design but I've
never encountered the catalog of problems and complications you profess
the likes of me to suffer from.

The only BB failure I've ever experienced was when a right side bearing
cup of a cheapo cup and cone BB snapped, spilling ball-bearings onto
the street.

A couple of my cranks, having outlived them, have been installed on
several incarnations of cartridge BBs without 'chainline drift' or harm
to their tapers.

I do my own wrenching and though am of average mechanical aptitude
regard the removal and installation of square taper cranks to be a
straight forward proposition -- it has never been problematic.

The issue of the small diameter square taper spindle's (long term)
durability, if it ever was a legitimate concern, has largely been
rendered moot with the advent of disposable cartridge bearing BBs.

>
> Yeah, other than those things, average riders have very few problems
> with them. But big, strong, or very high mileage riders break them.
>
> By any chance, do you like English cars?
>
> Chalo

I understand the equipment and design considerations attendant to your
extraordinary heft, but it must be acknowledged that less optimal
alternatives perform just as well for the rest. That's what a 100+
thousand KMs worth of experience has told me.

Luke

[jobst.brandt@stanfordalumni.org]

Chalo Colina writes:

>> Seriously, IME, decent quality square taper spindles have a very
>> low failure rate. I remain of the opinion that, for recreational
>> riders, "new" designs such as Octalink, ISIS and the now various
>> "external bearing" designs offer no discernible advantage and are,
>> in fact, purely marketing driven.

> By "recreational riders", might you mean people who don't ride hard,
> far, or often? Because such riders seem to do well with the square
> taper-- they don't over stress it and they don't have to remove and
> replace it much more often than they "upgrade" to new bikes.

> Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
> marketing-driven standards, but those are not the only games in
> town. OPC is a fine and reliable standard, as are the various
> 48-spline interference fitted interfaces, and the various 8- to
> 12-spline pinch- bolted interfaces, and the non-tapered square and
> hex pinch-bolted interfaces used in high quality BMX cranks. All of
> them display superior serviceability, longevity, and safety compared
> to the square taper.

Square taper spindle failures we so often see are from Wheelsmith
store in Palo Alto from the late 1960's and early1970's. One of the
failures broken through the square was mine and I never had another
after switching to Shimano spindles for my Campagnolo cranks. Since
then, I haven't seen another failure in the local bicycle shops.

I don't have a torque spec for these from either Shimano or Campagnolo
and rely on:

http://www.duke.edu/web/intramural/sportclubs/cycling/resources/torquespecs.htm

here the average torque specification for a square taper spindle lies
in the middle of the range given.

Jobst Brandt

[jim beam]

jobst.brandt@stanfordalumni.org wrote:
> Chalo Colina writes:
>
>>> Seriously, IME, decent quality square taper spindles have a very
>>> low failure rate. I remain of the opinion that, for recreational
>>> riders, "new" designs such as Octalink, ISIS and the now various
>>> "external bearing" designs offer no discernible advantage and are,
>>> in fact, purely marketing driven.
>
>> By "recreational riders", might you mean people who don't ride hard,
>> far, or often? Because such riders seem to do well with the square
>> taper-- they don't over stress it and they don't have to remove and
>> replace it much more often than they "upgrade" to new bikes.
>
>> Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
>> marketing-driven standards, but those are not the only games in
>> town. OPC is a fine and reliable standard, as are the various
>> 48-spline interference fitted interfaces, and the various 8- to
>> 12-spline pinch- bolted interfaces, and the non-tapered square and
>> hex pinch-bolted interfaces used in high quality BMX cranks. All of
>> them display superior serviceability, longevity, and safety compared
>> to the square taper.
>
> Square taper spindle failures we so often see are from Wheelsmith
> store in Palo Alto from the late 1960's and early1970's. One of the
> failures broken through the square was mine and I never had another
> after switching to Shimano spindles for my Campagnolo cranks. Since
> then, I haven't seen another failure in the local bicycle shops.
>
> I don't have a torque spec for these from either Shimano or Campagnolo
> and rely on:
>
> http://www.duke.edu/web/intramural/sportclubs/cycling/resources/torquespecs.htm
>
> here the average torque specification for a square taper spindle lies
> in the middle of the range given.
>

so where do all those 3-digit torque specs come from? campy don't
publish them. shimano don't publish them. do you have 3-digit torque
equipment? or are you simply posing for effect? [rhetorical]

[A Muzi]

>>>> Seriously, IME, decent quality square taper spindles have a very
>>>> low failure rate. I remain of the opinion that, for recreational
>>>> riders, "new" designs such as Octalink, ISIS and the now various
>>>> "external bearing" designs offer no discernible advantage and are,
>>>> in fact, purely marketing driven.

>> Chalo Colina writes:
>>> By "recreational riders", might you mean people who don't ride hard,
>>> far, or often? Because such riders seem to do well with the square
>>> taper-- they don't over stress it and they don't have to remove and
>>> replace it much more often than they "upgrade" to new bikes.
>>> Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
>>> marketing-driven standards, but those are not the only games in
>>> town. OPC is a fine and reliable standard, as are the various
>>> 48-spline interference fitted interfaces, and the various 8- to
>>> 12-spline pinch- bolted interfaces, and the non-tapered square and
>>> hex pinch-bolted interfaces used in high quality BMX cranks. All of
>>> them display superior serviceability, longevity, and safety compared
>>> to the square taper.

> jobst.brandt@stanfordalumni.org wrote:
>> Square taper spindle failures we so often see are from Wheelsmith
>> store in Palo Alto from the late 1960's and early1970's. One of the
>> failures broken through the square was mine and I never had another
>> after switching to Shimano spindles for my Campagnolo cranks. Since
>> then, I haven't seen another failure in the local bicycle shops.
>> I don't have a torque spec for these from either Shimano or Campagnolo
>> and rely on:
>> http://www.duke.edu/web/intramural/sportclubs/cycling/resources/torquespecs.htm
>> here the average torque specification for a square taper spindle lies
>> in the middle of the range given.

jim beam wrote:
> so where do all those 3-digit torque specs come from? campy don't
> publish them. shimano don't publish them. do you have 3-digit torque
> equipment? or are you simply posing for effect? [rhetorical]

Since none are produced in inchland they're likely Nm conversions as
Carl noted.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[jobst.brandt@stanfordalumni.org]

Michael Baldwin writes:

>> When the square taper was still king, we read about
>> failed cranks often. The square taper in the hands of
>> a skilled mechanic is foolproof and durable but the market
>> is not made of such bicyclists.

> I've reviewed Mr. Beam's attached photos of failures... my own
> experience says 3 of the 4 failures are related to over tightened
> crank bolts... there are other variables involved as well
> (stack-ups)...

That's not practically possible because crank bolts fail just beyond
the proper working torque. I've seen enough of such failures to know
it is not what can cause a spindle fracture. If you can explain how
an over tight bolt can cause spindle failure, I want to hear about it.

Jobst Brandt

[jim beam]

Michael Baldwin wrote:
>> When the square taper was still king, we read about
>> failed cranks often. The square taper in the hands of
>> a skilled mechanic is foolproof and durable but the market
>> is not made of such bicyclists.
>> --
>> Jobst Brandt
>
> ..I've reviewed Mr. Beam's attached photos of failures...my own
> experience says 3 of the 4 failures are related to over tightened crank
> bolts

your hypothesis needs to account for an important omission - bolts only
load on the first 3 threads. all those spindles are broken well outside
that zone.



>...there are other variables involved as well (stack-ups)...

that's over-load, not fatigue.

[Tim McNamara]

In article <1893-478A10AF-292@storefull-3112.bay.webtv.net>,
MLB5611@webtv.net (Michael Baldwin) wrote:

> >When the square taper was still king, we read about failed cranks
> >often. The square taper in the hands of a skilled mechanic is
> >foolproof and durable but the market is not made of such bicyclists.
> >-- Jobst Brandt
>
> ..I've reviewed Mr. Beam's attached photos of failures...my own
> experience says 3 of the 4 failures are related to over tightened
> crank bolts...there are other variables involved as well
> (stack-ups)...

Those usually weren't from single over-tightenings. What would happen
is that the bolt would be under-tightened, allowing the crank to squirm
up the square taper and the bolt becoming noticeably loose. It would he
inadequately re-tightened and the same thing would happen again. Repeat
the cycle a few times and voila! Serial under-tightening was the
problem.

I learned this at my first bike shop job in 1978. With the standard PB
wrench, you had to tightened down the bolt about as hard as you could.
With a wrench that short, it is difficult to over-tighten the bolt. I
use a torque wrench for convenience and have not had a crank loosen up
in many years, nor have I ever had a crank crack at the square taper
hole.

[Tosspot]

Tom Sherman wrote:
> Chalo Colina wrote:
>> ...
>> By any chance, do you like English cars?
>
> All the parts that fell off my MG were of the finest English quality!

I had a British car and went to the garage to get a spark pkug for it.
Garage owner said it was a fair swap.

I'll get me coat right now.

[Michael Baldwin]

>If you can explain how an over tight bolt can
>cause spindle failure, I want to hear about it.
>Jobst Brandt

...I've seen tolerance stack-ups, that when "variables collide", this
condition can occur...in the 80's I worked in Experiential Engineering
for GM's Oldsmobile Division...we were experiencing failures similar in
appearance to Mr. Beam's examples of spindle failure, at the bell
housing...long story short, it was a combination of threaded hole depth
(engine block) spot face depth (transmission case) combined with
excessive fastener clamp load, that would cause the mounting boss to
fail...NOT the fastener (in this particular case)...we wrote new
machining specifications to eliminate the stack-up interference and
strongly encouraged the Tonawanda assembly plant to keep their
multi-spindle assembly wrench back in process control...we were not
experiencing failures in our Lansing or Arlington facilities...

Best Regards - Mike Baldwin

[jobst.brandt@stanfordalumni.org]

Tim McNamara writes:

>>>> The fact that lightweight riders who don't ride many miles get by
>>>> with them is not an indication of their virtue; it's how they
>>>> hold up when put to a real challenge.

>>> You mean, average riders who put average to high mileage don't
>>> have any problem with them...

>> Other then chronic loosening, with permanent damage to the left
>> crankarm as a result. And cumulative wear and chainline drift from
>> repeated removal and reinstallation. And the necessity of having a
>> whole special set of tools to deal with them.

>> Yeah, other than those things, average riders have very few
>> problems with them. But big, strong, or very high mileage riders
>> break them.

> While not quite in your category (I am 6'4" 210 lbs and ride 6,000
> or so miles a year) I think I qualify as a "big, strong and/or high
> mileage" rider. I've never had one of these failures. The only
> square taper failure I have had was on my old Viscount, on which the
> BB axle snapped at the circlip groove after 8 years of service. I
> rode fewer miles in those days but on much hillier roads that are
> usually available to me now.

> The crank on the bike I ride most was purchased in 1994 (old Ritchey
> cold forged 110/74 square taper). I have a couple of these on
> different bvikes and use them with two rings and a Campy Veloce 116
> mm BB to obtain a "Q factor" of 140 mm. Properly installed I have
> found this to be a very durable design. While I am not creating the
> kinds of loading you are, given that you are much taller and heavier
> than I am, I do load the equipment more than the "average" person
> (5'10" and 175 lbs or so).

http://www.sheldonbrown.com/brandt/installing-cranks.html

Jobst Brandt

[jim beam]

A Muzi wrote:
>>>>> Seriously, IME, decent quality square taper spindles have a very
>>>>> low failure rate. I remain of the opinion that, for recreational
>>>>> riders, "new" designs such as Octalink, ISIS and the now various
>>>>> "external bearing" designs offer no discernible advantage and are,
>>>>> in fact, purely marketing driven.
>
>>> Chalo Colina writes:
>>>> By "recreational riders", might you mean people who don't ride hard,
>>>> far, or often? Because such riders seem to do well with the square
>>>> taper-- they don't over stress it and they don't have to remove and
>>>> replace it much more often than they "upgrade" to new bikes.
>>>> Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
>>>> marketing-driven standards, but those are not the only games in
>>>> town. OPC is a fine and reliable standard, as are the various
>>>> 48-spline interference fitted interfaces, and the various 8- to
>>>> 12-spline pinch- bolted interfaces, and the non-tapered square and
>>>> hex pinch-bolted interfaces used in high quality BMX cranks. All of
>>>> them display superior serviceability, longevity, and safety compared
>>>> to the square taper.
>
>> jobst.brandt@stanfordalumni.org wrote:
>>> Square taper spindle failures we so often see are from Wheelsmith
>>> store in Palo Alto from the late 1960's and early1970's. One of the
>>> failures broken through the square was mine and I never had another
>>> after switching to Shimano spindles for my Campagnolo cranks. Since
>>> then, I haven't seen another failure in the local bicycle shops.
>>> I don't have a torque spec for these from either Shimano or Campagnolo
>>> and rely on:
>>> http://www.duke.edu/web/intramural/sportclubs/cycling/resources/torquespecs.htm
>>> here the average torque specification for a square taper spindle lies
>>> in the middle of the range given.
>
> jim beam wrote:
>> so where do all those 3-digit torque specs come from? campy don't
>> publish them. shimano don't publish them. do you have 3-digit torque
>> equipment? or are you simply posing for effect? [rhetorical]
>
> Since none are produced in inchland they're likely Nm conversions as
> Carl noted.

so as an "engineer" he can't round the numbers? besides, shimano and
campy spec in Nm, so "converting" from Nm to ft-lbs and then back is
asinine.

[carlfogel@comcast.net]

On Sun, 13 Jan 2008 12:33:06 -0600, A Muzi <am@yellowjersey.org>
wrote:

>>>>> Seriously, IME, decent quality square taper spindles have a very
>>>>> low failure rate. I remain of the opinion that, for recreational
>>>>> riders, "new" designs such as Octalink, ISIS and the now various
>>>>> "external bearing" designs offer no discernible advantage and are,
>>>>> in fact, purely marketing driven.
>
>>> Chalo Colina writes:
>>>> By "recreational riders", might you mean people who don't ride hard,
>>>> far, or often? Because such riders seem to do well with the square
>>>> taper-- they don't over stress it and they don't have to remove and
>>>> replace it much more often than they "upgrade" to new bikes.
>>>> Yes-- Octalink, ISIS, Octalink II, Mega Exo, and Ultra Torque are
>>>> marketing-driven standards, but those are not the only games in
>>>> town. OPC is a fine and reliable standard, as are the various
>>>> 48-spline interference fitted interfaces, and the various 8- to
>>>> 12-spline pinch- bolted interfaces, and the non-tapered square and
>>>> hex pinch-bolted interfaces used in high quality BMX cranks. All of
>>>> them display superior serviceability, longevity, and safety compared
>>>> to the square taper.
>
>> jobst.brandt@stanfordalumni.org wrote:
>>> Square taper spindle failures we so often see are from Wheelsmith
>>> store in Palo Alto from the late 1960's and early1970's. One of the
>>> failures broken through the square was mine and I never had another
>>> after switching to Shimano spindles for my Campagnolo cranks. Since
>>> then, I haven't seen another failure in the local bicycle shops.
>>> I don't have a torque spec for these from either Shimano or Campagnolo
>>> and rely on:
>>> http://www.duke.edu/web/intramural/sportclubs/cycling/resources/torquespecs.htm
>>> here the average torque specification for a square taper spindle lies
>>> in the middle of the range given.
>
>jim beam wrote:
>> so where do all those 3-digit torque specs come from? campy don't
>> publish them. shimano don't publish them. do you have 3-digit torque
>> equipment? or are you simply posing for effect? [rhetorical]
>
>Since none are produced in inchland they're likely Nm conversions as
>Carl noted.

Dear Andrew,

The Park tool site gives similar torque values in inch-pounds for
square spindles, 305 to 391 for Shimano (main column) and details for
others, including Campagnolo at 312~324
http://www.parktool.com/repair/readhowto.asp?id=88

Shimano
inch-pounds 305~391
foot-pounds 25.4~32.6
newton-meters 34.4~44.2

So Shimano and Campagnolo are right around what Jobst suggested.

Some brands go as low as 240 inch-pounds and others as high as 521
inch-pounds.

Any $20 beam or clicker torque wrench will handle such ranges

Cheers,

Carl Fogel

[A Muzi]

-snip cranks-

Latest Campagnolo Record Pista manual says "32 to 38 Nm" FWIW.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[jim beam]

A Muzi wrote:
> -snip cranks-
>
> Latest Campagnolo Record Pista manual says "32 to 38 Nm" FWIW.

which gives a roughly +/-8% tolerance range from the mean - typical
engineering practice and somewhat different from less than 1% implied by
3-digit precision. most certified mechanical torque wrenches are +/-4%.
most certified off the shelf electronic are +/- 2%. better than that
requires serious coin and often special fastener surface interface
management.

[jobst.brandt@stanfordalumni.org]

Michael Baldwin writes:

>> If you can explain how an over tight bolt can cause spindle
>> failure, I want to hear about it.

> I've seen tolerance stack-ups, that when "variables collide", this
> condition can occur. In the 80's I worked in Experiential
> Engineering for GM's Oldsmobile Division. We were experiencing
> failures similar in appearance to Mr. Beam's examples of spindle
> failure, at the bell housing. Long story short, it was a
> combination of threaded hole depth (engine block) spot face depth
> (transmission case) combined with excessive fastener clamp load,
> that would cause the mounting boss to fail. NOT the fastener (in
> this particular case). We wrote new machining specifications to
> eliminate the stack-up interference and strongly encouraged the
> Tonawanda assembly plant to keep their multi-spindle assembly wrench
> back in process control. We were not experiencing failures in our
> Lansing or Arlington facilities.

Please excuse my editing your three-dot-periods. I did that to be
able to decipher what you wrote. Just the same, although I worked in
automobile design engineering, I cannot make head or tail of what it
means. I see no parallel in the parts described and BB spindles and
cannot guess what you mean.

Rather than relate what occurred at GM, can you explain the mechanical
effect that would cause a crank spindle to get a torsion failure from
excessive retaining bolt engagement?

You mention "we" and "our facilities". Who is "we" of whom you write?

Jobst Brandt

[jim beam]

jobst.brandt@stanfordalumni.org wrote:
> Michael Baldwin writes:
>
>>> If you can explain how an over tight bolt can cause spindle
>>> failure, I want to hear about it.
>
>> I've seen tolerance stack-ups, that when "variables collide", this
>> condition can occur. In the 80's I worked in Experiential
>> Engineering for GM's Oldsmobile Division. We were experiencing
>> failures similar in appearance to Mr. Beam's examples of spindle
>> failure, at the bell housing. Long story short, it was a
>> combination of threaded hole depth (engine block) spot face depth
>> (transmission case) combined with excessive fastener clamp load,
>> that would cause the mounting boss to fail. NOT the fastener (in
>> this particular case). We wrote new machining specifications to
>> eliminate the stack-up interference and strongly encouraged the
>> Tonawanda assembly plant to keep their multi-spindle assembly wrench
>> back in process control. We were not experiencing failures in our
>> Lansing or Arlington facilities.
>
> Please excuse my editing your three-dot-periods. I did that to be
> able to decipher what you wrote. Just the same, although I worked in
> automobile design engineering,

for how long?


> I cannot make head or tail of what it
> means. I see no parallel in the parts described and BB spindles and
> cannot guess what you mean.
>
> Rather than relate what occurred at GM, can you explain the mechanical
> effect that would cause a crank spindle to get a torsion failure from
> excessive retaining bolt engagement?
>
> You mention "we" and "our facilities". Who is "we" of whom you write?
>
> Jobst Brandt

[John Forrest Tomlinson]

On 14 Jan 2008 01:20:44 GMT, jobst.brandt@stanfordalumni.org wrote:

>Michael Baldwin writes:
>
>>> If you can explain how an over tight bolt can cause spindle
>>> failure, I want to hear about it.
>
>> I've seen tolerance stack-ups, that when "variables collide", this
>> condition can occur. In the 80's I worked in Experiential
>> Engineering for GM's Oldsmobile Division. We were experiencing
>> failures similar in appearance to Mr. Beam's examples of spindle
>> failure, at the bell housing. Long story short, it was a
>> combination of threaded hole depth (engine block) spot face depth
>> (transmission case) combined with excessive fastener clamp load,
>> that would cause the mounting boss to fail. NOT the fastener (in
>> this particular case). We wrote new machining specifications to
>> eliminate the stack-up interference and strongly encouraged the
>> Tonawanda assembly plant to keep their multi-spindle assembly wrench
>> back in process control. We were not experiencing failures in our
>> Lansing or Arlington facilities.
>
>Please excuse my editing your three-dot-periods. I did that to be
>able to decipher what you wrote. Just the same, although I worked in
>automobile design engineering, I cannot make head or tail of what it
>means. I see no parallel in the parts described and BB spindles and
>cannot guess what you mean.
>
>Rather than relate what occurred at GM, can you explain the mechanical
>effect that would cause a crank spindle to get a torsion failure from
>excessive retaining bolt engagement?
>
>You mention "we" and "our facilities". Who is "we" of whom you write?

Sounds like GM's Oldsmobile Division to me....

[Michael Baldwin]

>Mr. Brandt asks
>
>can you explain the mechanical effect that would cause a
>crank spindle to get a torsion failure from excessive retaining
>bolt engagement?

First let me state that I"m a "obsessive compulsive team player". Any
success that I've enjoyed in my many endeavors has always began by
checking my ego at the door. That's how I explain the "we and ours".

Next, as you are well aware of, the concept of variation is, no two
things are alike. I will not pretend to know all of the variables that
play a role in square taper spindle failures. I believe, as you some
what suggested in a previous reply, that the installer may very well be
the single largest contributing variable of square taper spindle
failure.

What if after several attempts to correct a chronically loose crankarm,
the installer fails to note that the spindle/crankarm interface has lost
considerable integrity. So much so that now, the end of the spindle and
the crankarm spotface are nearly flush. The crankarm bolt is
inserted,and the installer mistakes "good and tight" for what is
actually a bolt that is bottomed out in the threaded hole of the
spindle. The bolt, in a reasonably elastic state unable to transfer
it's energy into clamp load (elongation) expands instead in the area of
the first 3 threads. Normally this expansion should result in thread
fatigue (stripping). However this time (the concept of variation) the
bolt nor the threaded hole fail. This pressure eventually stresses
(cracks) the unsupported (diminished interface integrity) portion of the
square taper.

As I stated before, "when variables collied".

Best Regards - Mike Baldwin

[jobst.brandt@stanfordalumni.org]

Michael Baldwin writes:

>> can you explain the mechanical effect that would cause a crank
>> spindle to get a torsion failure from excessive retaining bolt
>> engagement?

> First let me state that I"m a "obsessive compulsive team player".
> Any success that I've enjoyed in my many endeavors has always began
> by checking my ego at the door. That's how I explain the "we and
> ours".

Your assurances suggest another aspect to your assessment of the
problem. What does that have to do with failure mode of crank
spindles?

> Next, as you are well aware of, the concept of variation is, no two
> things are alike. I will not pretend to know all of the variables
> that play a role in square taper spindle failures. I believe, as
> you some what suggested in a previous reply, that the installer may
> very well be the single largest contributing variable of square
> taper spindle failure.

From this I can only take it that you were working in the public
relations department where the cause of failure that you mentioned is
not revealed.

> What if after several attempts to correct a chronically loose
> crankarm, the installer fails to note that the spindle/crankarm
> interface has lost considerable integrity. So much so that now, the
> end of the spindle and the crankarm spotface are nearly flush. The
> crankarm bolt is inserted,and the installer mistakes "good and
> tight" for what is actually a bolt that is bottomed out in the
> threaded hole of the spindle.

I take it you don't have one of these spindles or you would know that
the internal threads are longer than the insertion length of the
retaining bolt, and that the retaining bolt is not capable of
lengthening under tension as much as one thread pitch if tightened to
failure, something that I have witnessed and was able to extract the
broken threaded end with the tip of my fingers.

> The bolt, in a reasonably elastic state unable to transfer it's
> energy into clamp load (elongation) expands instead in the area of
> the first 3 threads. Normally this expansion should result in
> thread fatigue (stripping). However this time (the concept of
> variation) the bolt nor the threaded hole fail. This pressure
> eventually stresses (cracks) the unsupported (diminished interface
> integrity) portion of the square taper.

Where do you get this stuff? First you say it was like an automotive
experience you had at GM and when asked about that you relate an
impossible elasticity scenario.

> As I stated before, "when variables collied".

I haven't seen that alibi before.

Jobst Brandt

[Ozark Bicycle]

On Jan 14, 1:07*am, jobst.bra...@stanfordalumni.org wrote:
> Michael Baldwin writes:
> >> can you explain the mechanical effect that would cause a crank
> >> spindle to get a torsion failure from excessive retaining bolt
> >> engagement?
> > First let me state that I"m a "obsessive compulsive team player".
> > Any success that I've enjoyed in my many endeavors has always began
> > by checking my ego at the door. *That's how I explain the "we and
> > ours".
>
> Your assurances suggest another aspect to your assessment of the
> problem. *What does that have to do with failure mode of crank
> spindles?
>
> > Next, as you are well aware of, the concept of variation is, no two
> > things are alike. *I will not pretend to know all of the variables
> > that play a role in square taper spindle failures. *I believe, as
> > you some what suggested in a previous reply, that the installer may
> > very well be the single largest contributing variable of square
> > taper spindle failure.
>
> From this I can only take it that you were working in the public
> relations department where the cause of failure that you mentioned is
> not revealed.
>
> > What if after several attempts to correct a chronically loose
> > crankarm, the installer fails to note that the spindle/crankarm
> > interface has lost considerable integrity. *So much so that now, the
> > end of the spindle and the crankarm spotface are nearly flush. *The
> > crankarm bolt is inserted,and the installer mistakes "good and
> > tight" for what is actually a bolt that is bottomed out in the
> > threaded hole of the spindle.
>
> I take it you don't have one of these spindles or you would know that
> the internal threads are longer than the insertion length of the
> retaining bolt, and that the retaining bolt is not capable of
> lengthening under tension as much as one thread pitch if tightened to
> failure, something that I have witnessed and was able to extract the
> broken threaded end with the tip of my fingers.
>
> > The bolt, in a reasonably elastic state unable to transfer it's
> > energy into clamp load (elongation) expands instead in the area of
> > the first 3 threads. *Normally this expansion should result in
> > thread fatigue (stripping). *However this time (the concept of
> > variation) the bolt nor the threaded hole fail. *This pressure
> > eventually stresses (cracks) the unsupported (diminished interface
> > integrity) portion of the square taper.
>
> Where do you get this stuff? *First you say it was like an automotive
> experience you had at GM and when asked about that you relate an
> impossible elasticity scenario.
>
> > As I stated before, "when variables collied".
>
> I haven't seen that alibi before.
>
> Jobst Brandt

Are you the same Jobst Brandt who wrote: "I hope people respond
without being rude and accept that people have different perspectives
[...] on bicycle components." on January 6, 2007 (a scant 8 days ago)?

http://preview.tinyurl.com/2hdtpd

or

http://tinyurl.com/2hdtpd

Physician, heal thyself!

[Michael Baldwin]

>As I stated before, "when variables collied". - Mike Baldwin
>
>I haven't seen that alibi before.
>Jobst Brandt

...in the spirit of being an "obsessive compulsive team player", I'm
choosing NOT to drag this discussion group through the mud...

Best Regards - Mike Baldwin

[Tom Sherman]

Ozark Bicycle wrote:
> On Jan 14, 1:07 am, jobst.bra...@stanfordalumni.org wrote:
>> Michael Baldwin writes:
>>>> can you explain the mechanical effect that would cause a crank
>>>> spindle to get a torsion failure from excessive retaining bolt
>>>> engagement?
>>> First let me state that I"m a "obsessive compulsive team player".
>>> Any success that I've enjoyed in my many endeavors has always began
>>> by checking my ego at the door. That's how I explain the "we and
>>> ours".
>> Your assurances suggest another aspect to your assessment of the
>> problem. What does that have to do with failure mode of crank
>> spindles?
>>
>>> Next, as you are well aware of, the concept of variation is, no two
>>> things are alike. I will not pretend to know all of the variables
>>> that play a role in square taper spindle failures. I believe, as
>>> you some what suggested in a previous reply, that the installer may
>>> very well be the single largest contributing variable of square
>>> taper spindle failure.
>> From this I can only take it that you were working in the public
>> relations department where the cause of failure that you mentioned is
>> not revealed.
>>
>>> What if after several attempts to correct a chronically loose
>>> crankarm, the installer fails to note that the spindle/crankarm
>>> interface has lost considerable integrity. So much so that now, the
>>> end of the spindle and the crankarm spotface are nearly flush. The
>>> crankarm bolt is inserted,and the installer mistakes "good and
>>> tight" for what is actually a bolt that is bottomed out in the
>>> threaded hole of the spindle.
>> I take it you don't have one of these spindles or you would know that
>> the internal threads are longer than the insertion length of the
>> retaining bolt, and that the retaining bolt is not capable of
>> lengthening under tension as much as one thread pitch if tightened to
>> failure, something that I have witnessed and was able to extract the
>> broken threaded end with the tip of my fingers.
>>
>>> The bolt, in a reasonably elastic state unable to transfer it's
>>> energy into clamp load (elongation) expands instead in the area of
>>> the first 3 threads. Normally this expansion should result in
>>> thread fatigue (stripping). However this time (the concept of
>>> variation) the bolt nor the threaded hole fail. This pressure
>>> eventually stresses (cracks) the unsupported (diminished interface
>>> integrity) portion of the square taper.
>> Where do you get this stuff? First you say it was like an automotive
>> experience you had at GM and when asked about that you relate an
>> impossible elasticity scenario.
>>
>>> As I stated before, "when variables collied".
>> I haven't seen that alibi before.
>>
>> Jobst Brandt
>
> Are you the same Jobst Brandt who wrote: "I hope people respond
> without being rude and accept that people have different perspectives
> [...] on bicycle components." on January 6, 2007 (a scant 8 days ago)?
>
> http://preview.tinyurl.com/2hdtpd
>
> or
>
> http://tinyurl.com/2hdtpd
>
> Physician, heal thyself!
>
I fail to see where J. Brandt was being rude.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[Tom Sherman]

Michael Baldwin wrote:
>> As I stated before, "when variables collied". - Mike Baldwin
>>
>> I haven't seen that alibi before.
>> Jobst Brandt
>
> ..in the spirit of being an "obsessive compulsive team player", I'm
> choosing NOT to drag this discussion group through the mud...
>
butbutbut, heated discussions on Usenet are FUN!!!

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

[jobst.brandt@stanfordalumni.org]

Michael Baldwin writes:

>> As I stated before, "when variables collied".

The above reference is a mystery to me. I don't know what variables
are involved nor what a collision of variables is. That I don't
understand this has nothing to do with mud. What does "obsessive
compulsive team player" have to do with the unanswered technical
questions at hand?

>> I haven't seen that alibi before.

> ..in the spirit of being an "obsessive compulsive team player", I'm
> choosing NOT to drag this discussion group through the mud...

As I said before, you speak in parables and I cannot decipher your
explanation for the crank spindles failures in question. That is, I
see no explanation for the helical torsional failures. The suggestion
that the retaining bolt caused the split gives no causal mechanism.

Jobst Brandt

[Ozark Bicycle]

On Jan 14, 6:10*pm, Tom Sherman <sunsetss0...@REMOVETHISyahoo.com>
wrote:
> Ozark Bicycle wrote:
> > On Jan 14, 1:07 am, jobst.bra...@stanfordalumni.org wrote:
> >> Michael Baldwin writes:
> >>>> can you explain the mechanical effect that would cause a crank
> >>>> spindle to get a torsion failure from excessive retaining bolt
> >>>> engagement?
> >>> First let me state that I"m a "obsessive compulsive team player".
> >>> Any success that I've enjoyed in my many endeavors has always began
> >>> by checking my ego at the door. *That's how I explain the "we and
> >>> ours".
> >> Your assurances suggest another aspect to your assessment of the
> >> problem. *What does that have to do with failure mode of crank
> >> spindles?
>
> >>> Next, as you are well aware of, the concept of variation is, no two
> >>> things are alike. *I will not pretend to know all of the variables
> >>> that play a role in square taper spindle failures. *I believe, as
> >>> you some what suggested in a previous reply, that the installer may
> >>> very well be the single largest contributing variable of square
> >>> taper spindle failure.
> >> From this I can only take it that you were working in the public
> >> relations department where the cause of failure that you mentioned is
> >> not revealed.
>
> >>> What if after several attempts to correct a chronically loose
> >>> crankarm, the installer fails to note that the spindle/crankarm
> >>> interface has lost considerable integrity. *So much so that now, the
> >>> end of the spindle and the crankarm spotface are nearly flush. *The
> >>> crankarm bolt is inserted,and the installer mistakes "good and
> >>> tight" for what is actually a bolt that is bottomed out in the
> >>> threaded hole of the spindle.
> >> I take it you don't have one of these spindles or you would know that
> >> the internal threads are longer than the insertion length of the
> >> retaining bolt, and that the retaining bolt is not capable of
> >> lengthening under tension as much as one thread pitch if tightened to
> >> failure, something that I have witnessed and was able to extract the
> >> broken threaded end with the tip of my fingers.
>
> >>> The bolt, in a reasonably elastic state unable to transfer it's
> >>> energy into clamp load (elongation) expands instead in the area of
> >>> the first 3 threads. *Normally this expansion should result in
> >>> thread fatigue (stripping). *However this time (the concept of
> >>> variation) the bolt nor the threaded hole fail. *This pressure
> >>> eventually stresses (cracks) the unsupported (diminished interface
> >>> integrity) portion of the square taper.
> >> Where do you get this stuff? *First you say it was like an automotive
> >> experience you had at GM and when asked about that you relate an
> >> impossible elasticity scenario.
>
> >>> As I stated before, "when variables collied".
> >> I haven't seen that alibi before.
>
> >> Jobst Brandt
>
> > Are you the same Jobst Brandt who wrote: "I hope people respond
> > without being rude and accept that people have different perspectives
> > [...] on bicycle components." on January 6, 2007 (a scant 8 days ago)?
>
> >http://preview.tinyurl.com/2hdtpd
>
> > or
>
> >http://tinyurl.com/2hdtpd
>
> > Physician, heal thyself!
>
> I fail to see where J. Brandt was being rude.
>

That is sad, but not at all surprising.

[Tim McNamara]

In article <fmgtk7$ivf$4@registered.motzarella.org>,
Tom Sherman <sunsetss0003@REMOVETHISyahoo.com> wrote:

> Ozark Bicycle wrote:
> > On Jan 14, 1:07 am, jobst.bra...@stanfordalumni.org wrote:
> >> Michael Baldwin writes:
> >>>> can you explain the mechanical effect that would cause a crank
> >>>> spindle to get a torsion failure from excessive retaining bolt
> >>>> engagement?
> >>> First let me state that I"m a "obsessive compulsive team player".
> >>> Any success that I've enjoyed in my many endeavors has always
> >>> began by checking my ego at the door. That's how I explain the
> >>> "we and ours".
> >> Your assurances suggest another aspect to your assessment of the
> >> problem. What does that have to do with failure mode of crank
> >> spindles?
> >>
> >>> Next, as you are well aware of, the concept of variation is, no
> >>> two things are alike. I will not pretend to know all of the
> >>> variables that play a role in square taper spindle failures. I
> >>> believe, as you some what suggested in a previous reply, that the
> >>> installer may very well be the single largest contributing
> >>> variable of square taper spindle failure.
> >> From this I can only take it that you were working in the public
> >> relations department where the cause of failure that you mentioned
> >> is not revealed.
> >>
> >>> What if after several attempts to correct a chronically loose
> >>> crankarm, the installer fails to note that the spindle/crankarm
> >>> interface has lost considerable integrity. So much so that now,
> >>> the end of the spindle and the crankarm spotface are nearly
> >>> flush. The crankarm bolt is inserted,and the installer mistakes
> >>> "good and tight" for what is actually a bolt that is bottomed out
> >>> in the threaded hole of the spindle.
> >> I take it you don't have one of these spindles or you would know
> >> that the internal threads are longer than the insertion length of
> >> the retaining bolt, and that the retaining bolt is not capable of
> >> lengthening under tension as much as one thread pitch if tightened
> >> to failure, something that I have witnessed and was able to
> >> extract the broken threaded end with the tip of my fingers.
> >>
> >>> The bolt, in a reasonably elastic state unable to transfer it's
> >>> energy into clamp load (elongation) expands instead in the area
> >>> of the first 3 threads. Normally this expansion should result in
> >>> thread fatigue (stripping). However this time (the concept of
> >>> variation) the bolt nor the threaded hole fail. This pressure
> >>> eventually stresses (cracks) the unsupported (diminished
> >>> interface integrity) portion of the square taper.
> >> Where do you get this stuff? First you say it was like an
> >> automotive experience you had at GM and when asked about that you
> >> relate an impossible elasticity scenario.
> >>
> >>> As I stated before, "when variables collied".
> >> I haven't seen that alibi before.
> >>
> >> Jobst Brandt
> >
> > Are you the same Jobst Brandt who wrote: "I hope people respond
> > without being rude and accept that people have different
> > perspectives [...] on bicycle components." on January 6, 2007 (a
> > scant 8 days ago)?
> >
> > http://preview.tinyurl