Are carbon cranks rhyming slang?

[Andrew Price]

Have now had 2 pairs of carbon cranks fail in my club - one Shimano, one
Campy but both at the point where an aluminium nut has the pedal spindle
screwed in (nut rotates uselessly in the shank).

Both were also less than 3 months old. Look nice, pity they don't work.

I question the technical wisdom of glueing an aluminium nut into a carbon
shank and then throwing some reasonable repetitive stress into that
equation.

Latest victim is being told the warranty claim will be satisfied by giving
him another carbon crank, rather than the "lesser" plain aluminium crank in
the same groupset he asked for - would have thought going the old reliable
alternative would have been a better/cheaper solution for everyone - or is
that seen as a manufacture's admission that they ain't got this one quite
right yet Orville?

Is there a wider experience of this problem out there?

rgds Andrew

 

[bfd]

"Andrew Price" <[email protected]> wrote in message
news:[email protected]...
> Have now had 2 pairs of carbon cranks fail in my club - one Shimano, one
> Campy but both at the point where an aluminium nut has the pedal spindle
> screwed in (nut rotates uselessly in the shank).
>
> Both were also less than 3 months old. Look nice, pity they don't work.
>
> I question the technical wisdom of glueing an aluminium nut into a carbon
> shank and then throwing some reasonable repetitive stress into that
> equation.
>
> Latest victim is being told the warranty claim will be satisfied by giving
> him another carbon crank, rather than the "lesser" plain aluminium crank
in
> the same groupset he asked for - would have thought going the old reliable
> alternative would have been a better/cheaper solution for everyone - or is
> that seen as a manufacture's admission that they ain't got this one quite
> right yet Orville?
>
> Is there a wider experience of this problem out there?
>
Does Shimano make a "carbon" crank? If so, what model is it? Thanks!

 

[[email protected]]

Shimano does not make a carbon crank. I personaly do not advise gluing
anything on a bicycle togeather, but you just can't weld, braze, or
silver solder plastic. I would say that these are just a coincidence
that two people in your club have hade the same thing happen to them.
The Italians use the same material for the underbody of the Ferrari
Endzo One, and that too is glued to the metal around it, that has far
more powerful forces at work then the pedal boss in a crankarm.
However they did warranty it, so it could be worse. In stress tests
carbon cranks last much longer then alu cranks, and all the recorded
failures have been in the alu pieces that get glued into the arm. I
have many bikes out there with camp carbon cranks on there and haven't
seen any problems, but only time will tell.
-Tim

 

[Andrew Price]

bfd wrote-

> Does Shimano make a "carbon" crank? If so, what model is it? Thanks!

I may have been unfair to Shimano - the bike is a Cannondale Synapse and on
their web site they specify the crank as Dura Ace but on looking at the
picture more carefully it seems to be a new type of Cannondale carbon crank
as pictured with Dura Ace being the alternative - see image at

http://www.cannondale.com/bikes/06/CUSA/model-6SC1X.html

Still have the same problem with the concept though.

best, Andrew

 

[Qui si parla Campagnolo]

Andrew Price wrote:
> Have now had 2 pairs of carbon cranks fail in my club - one Shimano, one
> Campy but both at the point where an aluminium nut has the pedal spindle
> screwed in (nut rotates uselessly in the shank).

shimano doesn't make carbon cranks-shimano compatible??
Aluminum nut has the pedal spindle screwed in-you mean the threads in
the crank? Helicoil or warranty. Use grease with the pedal?
>
> Both were also less than 3 months old. Look nice, pity they don't work.
>
> I question the technical wisdom of glueing an aluminium nut into a carbon
> shank and then throwing some reasonable repetitive stress into that
> equation.
>
> Latest victim is being told the warranty claim will be satisfied by giving
> him another carbon crank, rather than the "lesser" plain aluminium crank in
> the same groupset he asked for - would have thought going the old reliable
> alternative would have been a better/cheaper solution for everyone - or is
> that seen as a manufacture's admission that they ain't got this one quite
> right yet Orville?
>
> Is there a wider experience of this problem out there?

Seen this with aluminum cranks as well.
>
> rgds Andrew

 

[[email protected]]

Yea, aluminium cranks stripout as well. In fact if you don't use
grease when installing pedals you almost sure to have problems.
Shimano dosn't make any carbon parts, but many shimano compatible
carbon cranks do exist (mostly FSA).
-Tim

 

[Alex Rodriguez]

In article <[email protected]>,
[email protected].x1 says...
>
>
>Have now had 2 pairs of carbon cranks fail in my club - one Shimano, one
>Campy but both at the point where an aluminium nut has the pedal spindle
>screwed in (nut rotates uselessly in the shank).

I didn't know Shimano made carbon cranks. What model?

-------------------
Alex