An idea about cranks for unicycling

I would love to have cranks for unicycling, that I could change in length without getting off the unicycle. My thinking so far is, with some thread-and-cylinder-like construction, combined with a small motor and a control unit somewhere around the saddle or handle, this would be a great improvement for riding. Maybe 40 mm to move from shortest to longest, so position could go from 100 to 140 mm, using that to swith between road and off-road mode.
Thinking along this line, it would be useful or neccesary to have a vario-seatpost like MTB’s have, to adapt seat height to crank position.
Has there been any thinking or discussion in this direction? Since I’m not from the engineering side, what do you think about this?

I have been thinking about this about this since I was proficient enough to ride a few miles. Cranks have to withstand a lot of force and making parts small enough to allow for this mowing of pedals within a body that won’t hit the ankles or any other part of the foot would not be very strong or reliable. I have come to the conclusion that multi hole cranks are the only feasible answer.

1 Like

Martin Charrier have had a prototype. But this didn’t seem convincing.
BTW, vario-seatposts seem to be too fragile for unis… We put more force than bicyclists so they twist and they may finally break.