Spring loaded bicycle braking system , Does double duty as a Propulsion aid through gears . Feasible??
Basic Idea: When used to help slow(not primary brakes) a strong coil or spring is tightened to aid slowing. When maximum amount of tightness is reached the coil disengages somehow, The coil could be kept in the tight state until released for use for a burst of propulsion through reverse gears . Totally non-electric and light. It would be ideal for stop-and -go bike commuters , up and down hilly areas ,etc. Same idea could used for smaller cars, motorcycles,etc. Has this been used before ? Feasible ? Any critiquing of the concept is welcomed .