I'd like to hear from folks who haven't been able to use SPDs because of knee pain. I started with SPDs and, while I liked them, my knees didn't. I used to dance and have chondromalacia, and SPDs gave me anterior/medial knee pain. I switched to Speedplay Frogs and the knee pain disappeared, but I've been advised by a bike fitter/physical therapist that the unlimited float in Frogs makes for an inefficient pedaling path. He refit me for SPDs, and...the knee pain came back, so much as I'd like to make them work for me, apparently I can't.

So I am looking for a pedal system that provides 6-8 degrees of float, since I read in an article on cycling and knee pain that this is the optimal range of float for people with anterior/medial knee pain. So far I've found Speedplay Zeros and Crank Bros. Quattros to be in that ballpark. I would like to hear updates from those of you who use either system--how do you like them? And for those who use Frogs--do you find the unlimited float a problem in any way?

Thanks!