Patent ID: 7275624

Claim:
A disk brake unit for a motorcycle, having at least one piston built into a caliper body having a substantially U-shaped cross section with an outer section and an inner section connected by a bridge section, an outer pad attached to the outer section via an outer back plate, an inner pad attached to the inner section via an inner back plate, and an outer periphery of a brake disk inserted between the outer pad and the inner pad wherein on actuation of said piston, said outer pad and inner pad press said brake disk, wherein part of the piston projects beyond an outer peripheral edge of the brake disk to an outer side, the outer pad and the inner pad do not project out further than the outer peripheral edge of the brake disk, with the inner back plate and the outer back plate, that part corresponding to the piston is formed to have a portion which follows an outer peripheral edge of the piston, while the remaining part is formed to have a portion which follows the peripheral edge of the brake disk, and part of the bridge section projects further inwards than the outer peripheral edge of the piston by forming the bridge section to have a portion which follows the respective back plates.