After ACL replacement and meniscus grafts in both knees, I can say that BioPace chain rings have made it more comfortable to ride and have actually strengthened my knees! Of course, I've been using them since they were first introduced so I've always been sold on them. Oh, and BTW my cadence averages around 95-105 RPM.
frantik - I would keep the alignment marks right where they're designed to be. If you cannot get 'used' to them, then swap them out for round rings.
Just my insignificant opinion here, but rotating BioPace chain rings for 'better' efficiency... What, don't trust the original designers' R & D?
:I
Last edited by oldskoolwrench; 10-18-12 at 10:02 PM.