Originally Posted by
genejockey
*sigh*
If the pedal spindle travels in a circle, another point at a fixed distance in a fixed direction from the pedal spindle can only travel in a circle. It's path is DEFINED BY the path of the pedal spindle.
Ok good, you are starting to make my point. The pedal top IS a fixed distance away from the spindle, but, as it spins (or rocks) the magnitude of the contribution to the effective length of the crank changes, try it. lock the crank in one spot, and spin the pedal. Baby steps...