Abstract: A drum brake for bicycles including a cylindrical hub having a flange at both sides and a circular recess at an end thereof, a screw rod extending through the hub and supported by a bearing arranged within the hub, brake means including a rotor and three brake blocks fitted on the screw rod and installed with the circular recess, a positioning plate provided with three guide rods adapted to be slidably engaged with respective hole of the brake blocks, an arm having a square opening receiving the square portion, a torsion spring bearing against the arm, and a cover fixedly mounted on the positioning plate, whereby the bicycle can be effectively reduced in speed or stopped in motion.

Abstract: A hub brake for bicycles including a cylindrical hub in which is fitted a screw rod extending therethrough, a driving device including a driving screw, a bearing, an adjusting nut, a bearing and an arm, a recovering device including a torsion spring, a helical spring and a nut, and a braking device including a brake block and a positioning plate, and a cover fixedly mounted on the positioning plate, whereby the hub brake for bicycles can effectively reduce speed or stopping motion of a bicycle.