So on mine there is a smooth shaft with a smooth cam with a small spring. The considerable spring on the shaft, in theory, locks the cam in place. Given the strength of the spring, it must have been a chore to retract. Someone on the forum sent me an old magazine article saying that this design was the reason for the 'Pogo Stick' nickname, having caused numerous wrecks, and was improved after 200 units. Not hard to imagine why.
I have cut my side stand between the clamp and the pivot and am rewelding as an offset to get around the pipe. We'll see.