GimpyDavid

I am a 70 y/o male with a history of 5 left
Total Knee Replacements and would like to return to recreational bike riding.
However, I have only 95 degrees of left knee flexion which prevents me from completing a full crank revolution.
I would like some recommendations for acquiring asymmetric crank arms which will accommodate my left knee ROM
limitations. Thank you-GimpyDavid

groth

Not sure about asymmetric, but you could try short cranks or crank shorteners. I suppose if you did that only on the left, it would be asymmetric! In any case, crank shorteners are what I used before my total (right) knee replacement (and I only had 1, how did you ever do 5???).

Good luck,
Ed

OldTryGuy

5 ???? What happened, wearing out of joint, failure, improper installation, build up of scar tissue causing problems**********

I am years over-due for a right replacement that also requires an upper tibial osteotomy, actually left needs it also but not quite yet so curious as to what caused so many replacements.

Thank you.

+1 on the crank shortener

JoeKahno

Throwing a shorter crank arm on the left side shouldn't be a problem. The only possible issue I can see is that if you adjust the seat height to get minimum flex on the left, your other foot may want to lift off the pedal at the bottom of the stroke. It's worth a try. Worst case you may have to go to a matched set of shorter arms This will reduce your leverage slightly but shouldn't be anything you can't compensate for with the available gear ranges.

Doug64

This is a bike I gave to a freind. We shortened the left hand crank by drilling a new hole in the appropiate place to accommodate his left knee's limited range of motion. A local machinest driiled the hole, and our lbs tapped the 9/16" left hand threads for us. It worked well, but he did not do long rides with it.