Crank square taper...?



K

Kenneth

Guest
Howdy,

I know (barely) that the familiar square taper for mounting cranks on
BBs has been supplanted by something else.

Might you point me to a link that would show me the "something else?"

Sincere thanks,

--
Kenneth

If you email... Please remove the "SPAMLESS."
 
On Sun, 19 Sep 2004 17:59:05 -0400, Kenneth
<[email protected]> wrote:

>
>Howdy,
>
>I know (barely) that the familiar square taper for mounting cranks on
>BBs has been supplanted by something else.
>
>Might you point me to a link that would show me the "something else?"


Not "supplanted", at least not yet; the square taper remains the
design most often used for low-end, midrange and even some high-end
bikes. There are some competing types, though. The ISIS splined
design is popular with some users and manufacturers; it looks like
this:

http://tinyurl.com/4pn5j

The similar Shimano Octalink design has been reported to have problems
with cranks loosening in service, and seems to be falling out of favor
to some extent, though it's still widely available:

http://tinyurl.com/5qegf
http://tinyurl.com/6bm9s

Shimano has come out with a radically different (and very proprietary)
design for their high-end Dura Ace line. It features a right crank
and bottom bracket shaft that is integrated together into one unit,
making installation somewhat different.

Eventually, there probably will be a design that supplants the
venerable square taper, but despite its shortcomings, for the moment
it is still the type used on the majority of bikes sold.
--
Typoes are a feature, not a bug.
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On Mon, 20 Sep 2004 02:43:59 GMT, Werehatrack
<[email protected]> wrote:

>On Sun, 19 Sep 2004 17:59:05 -0400, Kenneth
><[email protected]> wrote:
>
>>
>>Howdy,
>>
>>I know (barely) that the familiar square taper for mounting cranks on
>>BBs has been supplanted by something else.
>>
>>Might you point me to a link that would show me the "something else?"

>
>Not "supplanted", at least not yet; the square taper remains the
>design most often used for low-end, midrange and even some high-end
>bikes. There are some competing types, though. The ISIS splined
>design is popular with some users and manufacturers; it looks like
>this:
>
>http://tinyurl.com/4pn5j
>
>The similar Shimano Octalink design has been reported to have problems
>with cranks loosening in service, and seems to be falling out of favor
>to some extent, though it's still widely available:
>
>http://tinyurl.com/5qegf
>http://tinyurl.com/6bm9s
>
>Shimano has come out with a radically different (and very proprietary)
>design for their high-end Dura Ace line. It features a right crank
>and bottom bracket shaft that is integrated together into one unit,
>making installation somewhat different.
>
>Eventually, there probably will be a design that supplants the
>venerable square taper, but despite its shortcomings, for the moment
>it is still the type used on the majority of bikes sold.


Howdy,

I sincerely appreciate your help...!

All the best,

--
Kenneth

If you email... Please remove the "SPAMLESS."
 
Kenneth-<< I know (barely) that the familiar square taper for mounting cranks
on
BBs has been supplanted by something else.

Might you point me to a link that would show me the "something else?"
>><BR><BR>


There are different designs, specifically spline type BBs from
shimano(Octalink) and others(ISIS) but square taper hasn't been 'supplanted'.
Square taper is alive and well on many cranks from many manufacturers.

There is no advantage of splined over a properly installed square taper.
Some disadvantages, most importantly teeny bearings that don't last very
long(ISIS).

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
rault-<< Shimano has come out with a radically different (and very proprietary)
design for their high-end Dura Ace line. It features a right crank
and bottom bracket shaft that is integrated together into one unit,
making installation somewhat different. >><BR><BR>

Actually not propriatary at all. FSA and others have designed this 'ala a
headset' type of external bearings.

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

> Not "supplanted", at least not yet; the square taper remains the
> design most often used for low-end, midrange and even some high-end
> bikes.


<pedant> But it's an octagonal taper really; have a close look. A real
square taper would crack the crank ;-)
 
In article <[email protected]>,
[email protected] says...
>Howdy,
>I know (barely) that the familiar square taper for mounting cranks on
>BBs has been supplanted by something else.
>Might you point me to a link that would show me the "something else?"


That was pretty much a Shimano idea. Do a google search on Octalink to
see the shimano way of doing it. The other new method is called ISIS.
A better Octalink type method. keep in mind that Campy still uses that
'old' square taper method. There is nothing wrong with it once you
understand how to use it properly.
----------
Alex
 
In article <[email protected]>,
[email protected] says...

>Shimano has come out with a radically different (and very proprietary)
>design for their high-end Dura Ace line. It features a right crank
>and bottom bracket shaft that is integrated together into one unit,
>making installation somewhat different.


pinch bolt onto a spline end is proprietary? it's been done before.
I think bullseye was (is?), doing that for some time.
-------------
Alex
 
On Mon, 20 Sep 2004 18:10:43 +0100, Zog The Undeniable
<[email protected]> wrote:

>Werehatrack wrote:
>
>> Not "supplanted", at least not yet; the square taper remains the
>> design most often used for low-end, midrange and even some high-end
>> bikes.

>
><pedant> But it's an octagonal taper really; have a close look. A real
>square taper would crack the crank ;-)


Howdy,

Are the other (very small) faces mating surfaces?

If not, then it would certainly seem appropriate to call it a square
taper...

All the best,

--
Kenneth

If you email... Please remove the "SPAMLESS."
 
On Mon, 20 Sep 2004 14:35:25 -0400, Alex Rodriguez <[email protected]>
wrote:

>In article <[email protected]>,
>[email protected] says...
>
>>Shimano has come out with a radically different (and very proprietary)
>>design for their high-end Dura Ace line. It features a right crank
>>and bottom bracket shaft that is integrated together into one unit,
>>making installation somewhat different.

>
>pinch bolt onto a spline end is proprietary? it's been done before.
>I think bullseye was (is?), doing that for some time.


Their precise choice of a spline size and shaping is certain to have
been made the subject of a design patent to prevent others from
supplying a compatible product. Not that it matters, since the DA
crank design is probably going to remain pricey enough to guarantee
that the square taper will have a long life ahead of it unless
something better comes along that's not restricted. The key is that
the square taper works *well enough* for the majority of riders that
there's not sufficient interest in coming up with an inexpensive
improved replacement.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
On Mon, 20 Sep 2004 14:35:25 -0400, Alex Rodriguez <[email protected]>
wrote:

>In article <[email protected]>,
>[email protected] says...
>
>>Shimano has come out with a radically different (and very proprietary)
>>design for their high-end Dura Ace line. It features a right crank
>>and bottom bracket shaft that is integrated together into one unit,
>>making installation somewhat different.

>
>pinch bolt onto a spline end is proprietary? it's been done before.
>I think bullseye was (is?), doing that for some time.


Their precise choice of a spline size and shaping is certain to have
been made the subject of a design patent to prevent others from
supplying a compatible product. Not that it matters, since the DA
crank design is probably going to remain pricey enough to guarantee
that the square taper will have a long life ahead of it unless
something better comes along that's not restricted. The key is that
the square taper works *well enough* for the majority of riders that
there's not sufficient interest in coming up with an inexpensive
improved replacement.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
What I'd like to know is, "why"? The ST crank/spindle has worked fine
for over a century.

Besides forcing everyone to shell out more money than necessary in order
to keep their bike running, is there any real reason to abandon a design
that has worked so well for so long?

- -

"May you have the wind at your back.
And a really low gear for the hills!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner
http://www.geocities.com/czcorner
 
On Mon, 20 Sep 2004 21:10:15 -0400, [email protected] (Chris
Zacho "The Wheelman") wrote:

>What I'd like to know is, "why"? The ST crank/spindle has worked fine
>for over a century.
>
>Besides forcing everyone to shell out more money than necessary in order
>to keep their bike running, is there any real reason to abandon a design
>that has worked so well for so long?


The urge to reinvent the wheel will always be with us. The urge to
try to make a profit by producing a different wheel that does the same
job as the old one will always be with us as well.

That said, even though it works very well, there is room for
improvement in certain areas. A system that flexes less under the
loads of elephants like me, and that has a more predictable chainring
position independent of installation torque on the retaining bolt,
would be my top two issues to address. On the other hand, something
that made strides in both areas but doubled the price of the bike
would be rejected out of hand by the majority of buyers; the
"ultimate" BB/crank design would not only correct the few faults of
the square taper, but would do so at approximately the same cost.

The fact that there isn't a credible candidate for "successor to the
square taper" at this point is a testament to the square taper's
principal virtue; a good blend of economy and performance.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
Alex Rodriguez writes:

> Keep in mind that Campy still uses that 'old' square taper method.
> There is nothing wrong with it once you understand how to use it
> properly.


That is an over statement considering the crank spindle failure being
discussed in this newsgroup now. The square taper fails now and then
usually causes serious injury as in the case under discussion. I have
had the experience and it isn't predictable.

Just consider that the square that supports the rider plus the force
of the other leg pulling up, on a piece of steel no larger than the
tip of an average little finger. Just hold yours up in front of you
and imagine the load that small element supports, millions of times.

Shimano is trying and I am not sure their solution is the right one.
At least it shouldn't break the spindle but it may have other flaws.

Jobst Brandt
[email protected]
 
Jobst-<< The square taper fails now and then
usually causes serious injury as in the case under discussion. I have
had the experience and it isn't predictable. >><BR><BR>

As does ISIS as does Octalink. It is a infrequent occurance(I have seen two in
nearly 20 years, a steel square taper fail).

In general, considering installation ease, strength, size of bearing balls,
cost, square taper is still a good system.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
Chris-<< What I'd like to know is, "why"? The ST crank/spindle has worked fine
for over a century. >><BR><BR>

Cuz they can. Change for change sake, not improving anything. More of an
attempt to take somebody out of the marketplace, making parts more expensive,
less people riding. The 'bike biz' needs to get it's collective head outta
their **** and figure out how to grow the cycling public numbers, not make
things unique, expensive and hard to find.

The bike biz, on the eve of Interbike, is awash in gadgets and gizmos and these
things do nothing to put a person that is new to cycling onna bicycle and keep
them there.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
On 21 Sep 2004 13:25:30 GMT, [email protected] (Qui si parla
Campagnolo ) wrote:

>Chris-<< What I'd like to know is, "why"? The ST crank/spindle has worked fine
>for over a century. >><BR><BR>
>
>Cuz they can. Change for change sake, not improving anything. More of an
>attempt to take somebody out of the marketplace, making parts more expensive,
>less people riding. The 'bike biz' needs to get it's collective head outta
>their **** and figure out how to grow the cycling public numbers, not make
>things unique, expensive and hard to find.
>
>The bike biz, on the eve of Interbike, is awash in gadgets and gizmos and these
>things do nothing to put a person that is new to cycling onna bicycle and keep
>them there.


Actually, it can work both ways. There are accessible gadgets and
then there is esoterica. Boutique stuff that is overpriced and
unattactive to the non-potential-cyclist doesn't help anything, but
affordable gadgets that might pique the interest of someone from the
general public can be beneficial. I'm fresh out of specific examples
of the latter for bikes, but for demonstrations of the phenomenon in
action, I will cite the early Ford Mustangs and the US marketing of
the VW Beetle in the late '60s and early '70s. In both cases, the
basic car could be dressed up with an almost endless variety of
accessories and/or options. With bikes, the most common types of
options historically were lights, silly kid-oriented decorations,
frame pumps, saddle bags, mechanical speedometers, front baskets, rear
baskets and/or racks, horns, bells, sirens, and the infamous banana
seats. Today, we can also add bar ends, bottle clips and bottles (if
the bike didn't come with them), digital speed/distance/time/BP/etc
comps, GPS units, tie-the-bike-to-your-feet devices that scare the
bejeesus out of a newbie, helmets, cycling wear that only the fit
should be seen in, hydration packs, and nifty tool kits. Now, out of
that whole list, what's going to grab the eye of the non-cyclist? If
you answer "Well, not much", you've got a handle on the bike accessory
problem from the *bike marketing* end. From the *cyclist marketing*
standpoint, most of those are good things to have available...but for
most of them, the potential buyer has to pretty much already be a
rider before they are interesting. (Except, perhaps, the nifty tool
kits and the GPS units, which are both a Guy Kind Of Thing...but not
cool enough to make somebody buy a bike just to have an excuse to
carry the Swiss Army Topeak Tool.)

So, what do *I* think the answer looks like? Simple. $5 a gallon for
gas. It may be closer than you think.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
Werehatrack <[email protected]> writes:

>The fact that there isn't a credible candidate for "successor to the
>square taper" at this point is a testament to the square taper's
>principal virtue; a good blend of economy and performance.


I have been impressed that Shimano can make a durable Octalink Bottom
Bracket with steel / chromoly that is only 222 grams. By comparison,
Campagnolo AC-H is 288 grams. If Shimano/FSA/Ritchey/etc. can solve
the crank : axle interface problems, then in the long run I think that
some sort of ISIS / Octalink bottom bracket will win. a 1-2 oz weight
savings in this area is compelling.

- Don Gillies
San Diego, CA
 
gillies-<< I have been impressed that Shimano can make a durable Octalink
Bottom
Bracket with steel / chromoly that is only 222 grams. By comparison,
Campagnolo AC-H is 288 grams. >><BR><BR>

Apples and oranges-Chorus is 220g, Record is 190g.

New Centaur is 230g.

gillies<< I think that
some sort of ISIS / Octalink bottom bracket will win. a 1-2 oz weight
savings in this area is compelling. >><BR><BR>

1-2 ounces is compelling?
You must be kidding. Why pay for propritary stuff that is less reliable and
saves 1-2 ounces??

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
rault-<< Boutique stuff that is overpriced and
unattactive to the non-potential-cyclist doesn't help anything, but
affordable gadgets that might pique the interest of someone from the
general public can be beneficial. I'm fresh out of specific examples
of the latter for bikes, >><BR><BR>

Me too. Rehash of old ideas. I haven't seen anything that makes people want to
ride more since index shifting and clipless pedals. Not for 2 decades.

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