I wish I had the bmx style motorbike my grandfather built. He spread the front fork, installed a rear free spinning sprocketed wheel, and installed a small electric motor on the handlebars. There was a small motorcycle battery on a tray over the rear wheel under the seat. You would manually pedal the bike to speed, then turn a key and the electric motor would get you up to a nice cruising speed, turn the key back off and coast. I'd imagine with a small solar panel it would be the ideal commuter bike for the lazyh: The thing booked, I believe my cousin clocked it over 40mph along side a car. My grandfather use to build all kinds of crazy contraptions, solely responsible for my ability to turn a wrench and fix things