Bicycle wheel rim capable of cooperating with brake shoes to bring about smooth and stable braking action

摘要

A bicycle wheel rim is composed of a friction surface extending along the rim. The friction surface is provided with a plurality of action units each having a primary action area and a secondary action area and a secondary action area. The primary action area has a flat surface capable of frictional engagement with the brake shoes of a bicycle brake system. The secondary action area has a concave surface capable of frictional engagement with the brake shoes of the bicycle brake system. The action units of the bicycle wheel rim are thus capable of cooperating with the brake shoes to bring about a smooth and stable braking action for slowing or stopping the bicycle wheel in motion.