We are using a kinetic energy recovery system by designing the flywheel for recovering the moving bicycle energy under braking and also to convert the usual loss in kinetic energy into a gain. While riding a bicycle, a great amount of kinetic energy is lost while braking. To use this energy, we are using a flywheel to store the energy, which is normally lost during braking and reuses it to help propel the rider when starting. By designing the flywheel which is more suitable to the frame properties and rider compatibility, the efforts of the rider can be reduced. The rider can charge the flywheel during downward motion on a hilly road and boost the bicycle when accelerating. This project preliminary deal with one of the methods for recovering the kinetic energy from the Flywheel, which is implemented in a bicycle. In this regenerative braking system, we are concentrating on the mass of the flywheel and re-designing it. A flywheel is used which stores the energy when brakes are applied and then the saved energy is used to give push start to the bicycle.