Crank Arm Spacing

[Bob Devany]

I measured the distance between the chainstay and inside of the left and right crank arms at the
pedal threads and found that right arm (drive side) was about 2 mm further from the chainstay than
the left arm. This is on a Campy triple with both arms set at the same torque. My Shimano bike
showed a similar discrepancy. From a biomechanical perspective this seems flawed to me. Is there a
fix? I'm having problem with pain on the outside of my left knee so any ideas or fixes would be much
appreciated.

 

[One Of The Six]

The reason for it is the chainline. It is fairly common for the driveside crank to be a little
farther out. Especially with triples. Most likely nothing to worry about. Nothing about our anatomy
is symetrical. Your legs are probably different by a few millimeters, your foot size probably is
also. Does your left foot point dramatically outward (heels inward) during your normal walk? If not
I would tend to doubt the problem you are having with your left knee is caused by the right crank
being a few mm farther out. Usually narrower cranks are considered to be better for your knees.

"Bob Devany" <[email protected]> wrote in message
news:[email protected]...
> I measured the distance between the chainstay and inside of the left and right crank arms at the
> pedal threads and found that right arm (drive side) was about 2 mm further from the chainstay than
> the left arm. This is on a Campy triple with both arms set at the same torque. My Shimano bike
> showed a similar discrepancy. From a biomechanical perspective this seems flawed to me. Is there a
> fix? I'm having problem with pain on the outside of my left knee so any ideas or fixes would be
> much appreciated.

 

[Qui Si Parla Ca]

bob-<< was about 2 mm further from the chainstay than the left arm. This is on a Campy triple with
both arms set at the same torque. My Shimano bike showed a similar discrepancy.

Not uncommon but I don't think this 2mm is causing the knee pain or something that can't be
corrected with a pedal/cleat/bike fit.

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

 

[Paul Kopit]

You can install a 2 mm washer under the appropriate pedal before attachment to crank and see if that
makes any difference, which I doubt it will. If the washer does make a difference, leave it there or
adjust cleat on shoe.

On 23 Jan 2003 13:46:05 GMT, [email protected] (Qui si parla Campagnolo) wrote:

>Not uncommon but I don't think this 2mm is causing the knee pain or something that can't be
>corrected with a pedal/cleat/bike fit.
>
>
>Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
>(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[mtf125]

Check out this page, It might explain why you have knee pain.
http://www.rivbike.com/html/101_cranks.html