As a Surplus Center degenerate browser I have been spending time looking at their selection of tiny hydraulic motors/pumps. I have a 750 watt, homebuilt e mini bike with a deep reduction Nuvinci 171 Developer's Kit (i.e. auto trans) and I day dream about making it a 2wd ride. I know that there are tech issues, but I can calc torques/pressures, chain pulls/chain speeds etc. ok, and think I could figure out a theoretical design that could work. But I don't wanna grow the bike just to make it 2wd. Has anyone else either thought or acted on a similar project?