Crank Arm Spacing

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.

 

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.

 

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"

 

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"

 

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