The function of the clutch is very simple. The function of the clutch is equivalent to transmitting the power of the engine to the resistance box as a bridge, but there will be different speeds and torques in the transmission process. The faster the speed is, the higher the gear ratio is. Therefore, the function of the clutch is needed in this process, that is, to switch gears and match the speed of the gearbox at different times. With the clutch, we can directly match the different speeds with the different gears of the gearbox. It plays a transitional role. We didn't step on the clutch, that is, we separated the engine speed from the gear of the gearbox.