Bicycle Trivia (3) - Flywheel

     The flywheel is the passive gear at the rear end of the bicycle chain, which has an internal thread inside in order to fix it at the right end of the rear axle, maintain the same plane with the sprocket, and connect with the sprocket through the chain to form the drive system of the bicycle.

     The number of gear sets is different, and the flywheel can be divided into two categories: single-stage flywheel and multi-stage flywheel. Single-stage flywheel, also known as single-chain wheel blade flywheel, is installed on ordinary bicycles, mainly composed of jackets, flat gears, cores, jacks, jack springs, gaskets and other parts.

     Single-stage flywheel working principle: When the foot pedal is stepped forward, the chain drives the flywheel to rotate forward, at this time the flywheel inner teeth and jack are contained, the flywheel's rotation power is transmitted to the core through the jack, and the core drives the rear axle and rear wheel rotation. When the pedal stops moving, neither the chain nor the flywheel rotates, but due to inertia, the rear axle and rear wheel will continue to rotate, at which point the teeth in the flywheel will slide relatively, thereby compressing the core into the groove of the core, and the jack spring is compressed.When the jack of the jack-of-a-million-pound tooth slides to the top of the inner tooth of the flywheel, the jack spring is compressed the most, and then slides forward slightly, and the jack-in-the-jack is bounced onto the root of the tooth by the jack-in-the-jack spring, making a "clicking" sound. When the pedal rotates in turn, the sheath rotates backwards, which will accelerate the sliding of the jack, making the "click" sound more urgent.

     Multi-stage flywheel is based on a single-stage flywheel, adding several pieces of flywheel pieces, each flywheel piece has a different number of teeth, they are combined with the sprocket on the central shaft, forming a variety of different transmission ratios, thereby changing the speed of the bicycle, so the multi-stage flywheel is an important part of the bicycle transmission device.