I remember in the dominican republic we made scooters that were powered with rubber bands. You would wind up the rubber bands with a pully and gear and it would stretch them very very tight. We used at least four on the rear wheel ... to release the energy you used a trigger system and you used a brake handle to control the amount of force. It functioned almost like an e-bike but with rubber bands! Eventually we figured out how to wind the rubber bands with the pedals and you could wind the rubber bands and then go ... they became really popular and you would see tons of them on the road during that era .... it was always fun watching how people came up with inventions to harness the power of energy .