Bicycle seat cover, the main component of the seat cover is SBR composite nylon and spandex fabric, with polyurethane foam filling. The bottom is made of chemical fiber anti-slip fabric, and the edge fabric is PK fabric. The main function of the seat cover is to provide comfort. It enhances the comfort of the saddle during riding. The seat cover completely wraps around the saddle, and the bottom of the seat cover is equipped with anti-slip particles. During riding, it is less likely to deviate. The seat cover reduces the pain during long-term riding for us.

The bicycle axle is an important component of a bicycle, located between the wheels and the frame. Its main function is to transfer the force from the pedals to the wheels, enabling the bicycle to move. The axle is divided into the front axle, the middle axle and the rear axle, each of which performs different functions and roles.
Front axle
The front axle is located at the center of the front wheel and serves mainly as a supporting structure, not directly transmitting torque. The front axle is a pinion shaft because it only bears bending moments and does not transmit torque. 12
Axle
The axle is located in the middle of the bicycle, usually at the position where the pedals are. The axle is a rotational axis that bears both bending moments and torques, thus belonging to a rotating shaft (23). The main function of the axle is to transfer the force from the pedals to the rear wheel, driving the bicycle forward.
Rear axle
‌The rear axle‌ is located at the center of the rear wheels and mainly bears bending moments but does not transmit torque. Therefore, it is referred to as a heart shaft‌‌23. As a fulcrum, the rear axle supports the rear wheels and bears the reaction forces from the wheels and the ground.