The mission of the beach bike gear is to ensure that the beach bike can operate efficiently and stably in various complex terrains. Specifically, their mission includes the following aspects:

1. Power transmission: The main function of a beach bike gear is to transmit the power generated by the engine to the driving wheels, thereby pushing the vehicle forward or backward.

2. Increase torque: When driving at low speeds, gear design can provide a larger torque to help the vehicle overcome resistance when climbing hills or on soft sandy terrain.

3. High speed driving: When driving at high speeds, the gear design can maintain the speed stability of the vehicle and adapt to the driving needs under different road conditions.

4. High reliability: As beach bikes are often used in harsh environments, gears need to be made of high-strength materials and processed with high precision to ensure their wear resistance and impact resistance, thereby improving the lifespan and reliability of the gears.

5. Strong adaptability: The gears of beach bikes can adapt to different usage conditions and scenarios, meeting the needs of various brands and models of beach bikes.

6. Maintenance: The structural design of gears should be easy to repair and maintain, in order to reduce maintenance costs and improve vehicle maintenance efficiency.

In short, the mission of beach bike gears is to provide stable and efficient power transmission for beach bikes, ensuring that the vehicle can perform well in various complex terrains.