Abstract: A regenerative braking system provides braking by transmitting the spring force of a deforming elastic medium as a torque tending to oppose the forward rotation of a wheel being braked. A brake pad assembly, mounted concentrically with the hub of a ground-engaging wheel, is actuated upon braking to provide frictional engagement between the hub and a wrapping mechanism which reels in a cable attached to an elastic medium, thereby deforming the elastic medium and storing energy, while applying a decelerating torque to the wheel. The wrapping mechanism is engaged only upon braking, and does not interfere with wheel rotation during other vehicle operating modes. Energy is accumulated until the deforming elastic reaches a limit stop, at which point continued braking is provided by frictional slippage between the brake pad and the rotating hub.