Anti-brake system for bicycles

A brake system adapted to be connected to a front fork or seat stays and activated by a brake cable so as to clamp a disk, the brake system comprising:

• a frame located on a side of the disk and a rack arranged on a side of the frame;
• a positioning member including a main part which is adapted to be fixed to the front fork or the seat stays;
• a clamping assembly adapted to be movably connected onto the disk, and operatively connected to the frame and the positioning member, the clamping assembly including a clamp member which has a slot so as to be adapted to receive the disk therein, a passage defined in the clamp member and two blocks located below the passage;
• an activation member slidably received in the passage of the clamp member and connected to the frame, a groove is defined in each of two sides of the activation member and two springs received in the two grooves, one of two ends of each of the springs engaged with protrusions extending from the insides of each of the grooves, the other end of each of the springs contacting the blocks;
• a pawl located in the clamp member and including teeth engaged with the rack, a plurality of beads installed at a side of the pawl;
• a main shaft located in the clamp member and between a side of the disk and the pawl, a plurality of tear-shaped recesses defined in a side of the disk portion and each recess including a shallow portion and a deep portion;
• an adjusting cover located in the clamp member and on the other side of the disk, and
• two linings located on the two sides of the disk and between the main shaft and the adjusting cover, the linings adapted to clamp the disk when the brake cable is pulled.