I actually was told that I had to get rid of my Speedplays and go to a no float pedal... this was after having severe knee pain (lateral collateral ligament) and getting a fit by John Howard (if you don't know who he is google him and be amazed!)... anyway, amongst other things he specifically told me I had to go to a no float pedal because it was allowing me to turn my knee outward, which can happen especially during climbing when you're tired!!! This was not the only issue, but a definite contributing factor... I now ride Zero's as they can be set for no float...