It depends on what causes your knee pain. I have this thing where my thigh bone jabs down into the cartilage under my knee cap. I guess this is somewhat common. I think fixies helped me because they work my thigh muslces more effectively, which inturn stops this process of wearing down that cartilage. This is a wonderful thing. Now if I can figure out a way of teaching five classes a day without standing, the universe will return to a state of balance.