Abstract: A brake system for a motor-driven vehicle includes a brake device driven by a brake cable to stop the motor-driven vehicle from moving, two electrically conductive friction means respectively fastened to the brake device and driven by the brake device to press on two opposite sides of a metal part of wheel means of the motor-driven vehicle in stopping the motor-driven vehicle from moving, a main processor, which controls the operation of the motor of the motor-driven vehicle, and two electric wires respectively connected between the electrically conductive friction means and two opposite terminals of the main processor; wherein when the electrically conductive friction means are forced by the brake device to press on the two opposite sides of the metal part of the wheel means of the motor-driven vehicle, the main processing unit is induced to cut off power supply from the motor of the motor-driven vehicle.

Abstract: A vehicle pedal power saving mechanism mounted on the axle of the pedal cranks of a vehicle to facilitate pedaling of the pedal cranks, the vehicle pedal power saving mechanism including a side board mounted on the frame structure of the vehicle, a big gear coupled to the axle of the pedal cranks by an one-way ratchet wheel assembly, a small gear meshed with the big gear, a piston moved in a cylindrical shell at the side board and supported on a spring member inside the cylindrical shell, and a link coupled between the piston and a pivot at the small gear to reciprocate the piston upon rotary motion of the big gear and the small gear.