A micro-adjusting device of the bicycle brake holder is composed of a cap, an adjusting seat, a ferrule, an elastic body, and an adjustment bolt. The cap is mounted on the adjusting seat which is engaged with the ferrule fastened with the bicycle brake holder. The elastic body has a horizontal end which is fastened with the cap, and a vertical end which is received in a through hole of the head of the adjustment bolt. The adjustment bolt has a threaded body which is adjustably located in an adjustment slot of the bicycle brake holder. The adjustment bolt is securely located at a position in the adjustment slot of the bicycle brake holder by a fastening nut which is engaged with the threaded body of the adjustment bolt.
An improved structure of a brake-tuning device for a bicycle, and in particular, relates to a tuning device for the brake of a bicycle by having an adjusting bolt to regulate the distance between the brake arm and the wheel frame so that the braking operation is effective. The brake-tuning device comprises a brake arm, a holding seat urging the lateral edge of the brake arm, an adjusting bolt being mounted onto the holding seat, an adjusting rim mounted on the holding seat, a cable having one end mounted to the brake arm and the other end mounted to the holding seat, and an annular insert mounted on the fork of the bicycle and being used to secure the brake-tuning device thereto.
A bike cantilever brake arm having a sleeve fixed to the brake arm through an axle bore provided at the bottom of the brake arm; a scroll section of the rod spring being inserted to a ring provided on one side of the sleeve and covered with a cap; a locking ring is provided on one side of the sleeve to receive insertion of a rubber ring from the opposite side of the adjustment base; a slot and a hooking section being provided on one end of the rubber ring to merely engage the locking ring of the sleeve; another end of the rubber ring extending a retaining edge to retain the adjustment base; and the brake arm, the cap, the rod spring and the adjustment base all being ex-factory made in one piece to keep them integral during transition and the subsequent assembly.
