Originally Posted by
wheelreason
Ok, so I think I said something similar above, and I'm still firmly in the not a circle camp. But I had a couple of hours of riding time to think about it and yes, the pedal would track a circle if it was orthogonal to the crankarm at all times all the way around, but that is just a special case of keeping the stack from changing the overall distance from the center as the pedal spindle rotates (or rocks), as it travels around, which can be accomplished by locking the pedal from spinning in any position, no?
Seems like you are talking about this:
But you wouldn't be able to pedal on such a configuration.
My diagram shows the pedal in the same orientation to the ground throughout the stroke but it doesn't do that in reality.