Kinetic energy recovery system (KERS) is a method used in automobiles for recovering the energy lost in braking of the automobiles and thus providing speed to the vehicle motion. In that same concept for braking regenerative can be applied in bicycle. When riding a bicycle, a great amount of kinetic energy is lost while braking, making start up fairly strenuous. Which method uses a flywheel? Flywheel will be mounted between the frames of the bicycle, in that flywheel can store the braking energy by rotating and this energy can be required time given to the system in that term engagement and disengagement mechanism used to reduce the pedaling power required to drive the bicycle. This Flywheel Energy Storage system uses flywheel with suitable clutch mechanism along with sprocket and chains. The flywheel increases maximum acceleration and nets 10% pedal energy savings during a ride where speeds are between 13 and 15 mph. Further this concludes about efficiency and pedaling power in flywheel bicycle.