That was an interesting read John.

It sort of goes against my own simplistic understanding of what goes on in pedaling. I'm getting twinges in my left knee at the moment when riding my 54" geared Strida copy. It comes on when I'm going up hill as the force increases to maintain speed. I HAD thought that shorter cranks would require that more force be applied to maintain a specific power at the rear wheel, since the leverage would be shorter and hence more pressure would be needed. However, I had not thought about the amount of angle the knee joint needs to operate through, and to be honest, I can't just visualise that at this moment. I'm going to have to sit down with a pencil and do some drawings to work out how it affects the knee.