How about adding a derailleur to the axle end, making it like a five speed or so? Get started in low gear, gain some speed and start shifting up, and as we find ourselves motoring down the lake or trail, pretty much up on a plane, get some reasonable speed out of the machine, hopefully without expending too much energy. Get really crazy, and add a sprocket derailleur as well. How about disc brakes on the rear wheels? My goodness, man, the possibilities are endless.
