If I go for an easy ride my knees don't hurt at all for the most part. It seems like I warm up enough ( 15 to 20 minutes), but when I try and put to much preasure on the knee, I have my problem. Maybe I should do some work outs on my right knee only. I though after riding as much as I have that my knee would be ready for more of a work out. I think the pedals have 5 or 6 degrees and I do leave my shoes a little lose. Besides my shoe being lose and the pedals set at hardly any pressure at all, I don't think that's it. I tried that out this morning and I got all kinds of play. I know the Shimano M424 aren't a real road pedal, but I've had the best results from them so far. They did help with the knee pain. Maybe your on to something, but I wonder why on one side only. It sure would be worth a try though, thanks again.