The working principle of its single-stage flywheel: when the pedal is stepped forward, the chain drives the flywheel to rotate forward. At this time, the inner teeth of the flywheel are combined with the kilo. The rotating force of the flywheel is transmitted to the core through the kilo. The core drives the rear axle and rear wheel to rotate, and the bicycle moves forward.

Sprocket is a kind of wheel with cogged sprocket, which is used to mesh with the block with accurate pitch on the chain link or cable. Sprockets are widely used in chemical industry, textile machinery, escalators, wood processing, three-dimensional parking garages, agricultural machinery, food processing, instrumentation, oil and other industries. The bicycle sprocket is made of high-strength steel to ensure that it reaches the required tension.