The free stroke of the brake pedal of the service brake system shall comply with the relevant technical conditions of the vehicle.

1. The pedal force when the service brake produces the maximum braking effect shall be less than or equal to 500 N for passenger cars; 700 N or less for other motor vehicles. The pedal force producing the maximum braking effect of the service braking system of motorcycles (except regular tricycles) shall be less than or equal to 400 N, and the grip force shall be less than or equal to 250 N.

2. When the hydraulic service brake reaches the specified braking efficiency, the pedal travel (including idle travel, the same below) shall not be greater than three fourths of the full pedal travel; The pedal travel of motor vehicles equipped with automatic clearance adjustment devices for brakes shall not exceed four fifths of the total pedal travel, and shall not exceed 120 mm for passenger cars, and 150 mm for other motor vehicles.

The first electric tricycle in the world was born in 1881. Its inventor was Gustav Truff, a French engineer. It was a tricycle powered by a lead-acid battery. In 1873, the electric vehicle, which was invented by Robert Davidson, an Englishman, powered by a primary battery, was not included in the scope of international confirmation. Later, lead-acid, nickel cadmium, nickel hydrogen batteries, lithium-ion batteries, and fuel cells emerged as electric vehicles

If an internal combustion engine is used, its cylinder displacement is greater than 50mL, or regardless of the driving mode, its maximum design speed is greater than 50km/h. Including two wheeled motorcycles, side three wheeled motorcycles and regular three wheeled motorcycles (side three wheeled motorcycles and regular three wheeled motorcycles can be collectively referred to as three wheeled motorcycles)