I was reading the which "clipless and why" thread and I got to thinking..... After years of riding clipless pretty much all the time I'm now running platforms on my bikes. I went out for a ride yesterday running my Time pedals and about 6 miles in my knee starts giving me problems again.When I got home I ditched the clipless and went with a set of platforms. Now when I ride with my old Vans/flats setup,no problems. I am finding that I am just more comfortable riding on flats now days.