Patent ID: 8544616

Claim:
A brake disk for bicycles comprising: an inner disk having multiple inner fastening holes formed through and annularly arranged separately on the inner disk; two outer disks respectively mounted on two sides of the inner disk, clamping the inner disk, and each outer disk having multiple outer fastening holes formed through and annularly arranged separately on the outer disk; and multiple brake units mounted in the inner disk and the outer disks, clamped between the outer disks, and each brake unit having a flange segment mounted in one of the inner fastening holes of the inner disk, and two opposite surfaces of the flange segment respectively abutting the outer disks; and two protrusions respectively formed on the two opposite surfaces of the flange segment, respectively mounted in one of the outer fastening holes of the outer disks, and protruding out of the outer disks; wherein an area of the flange segment is larger than an area of each protrusion; and the brake units are made of materials with high abrasion resistance, high temperature resistance, and low heat conduction.