To provide a small and lightweight antilock brake device generating a less sound or a less vibration by forming a unit with a solenoid valve, a reservoir, an auxiliary electronic control device and a liquid-operated pump operable on the rotation of a wheel, all as one group, and mounting the unit on a knuckle as an axle support member.

An antilock brake unit 30 is formed out of solenoid valves 21 and 22, a liquid-operated pump 23, a reservoir 24, and an auxiliary electronic control device 30, and this antilock brake unit 30 is mounted on a knuckle to support an axle 4. Also, the liquid-operated pump 23 contained in an antilock unit is formed so as to be driven with the cam 26 of the axle 4.