Quote Originally Posted by Triskeliongirl
Do know that if you ever feel the need, its not a big deal to swap out that 48 for a 50. Also, be aware that sometimes knee problems can be fixed with saddle height adjustments, and cleat positioning and/or increasing float. I know since I did all of the above! I like speedplay pedals with lots of float, and even then my cleats have to be mounted just right, and my saddle has to be high enough or I get knee pain. My recommendation to use the 50 shouldn't effect anything, since you won't compromise on your low range, but you'd have another high gear to not spin out on descents or in a tail wind, which also shouldn't bother your knee.
Thanks but my knee problem is recovering from ACL surgery in Feb. It's getting stronger but still has not regained the strength of my uninjured leg. And yes, I know that I can go with a 50, I plan to do that when my knee regains its full strength. Dr. says it's a year until it's fully healed.