Abstract: An arrangement for supporting a reflector on a bicycle includes a special washer and a reflector attaching bracket, the washer and bracket are held between a brake unit and a front fork crown or a seat stay bridge by a center bolt. The special washer is provided with a hole for allowing the center bolt to penetrate therethrough and, on one face thereof, a concave surface is formed complementary to a curved surface on the front fork crown or a seat stay bridge. A lapping portion of the reflector attaching bracket which is brought into contact with the special washer is provided with a cut-out space for allowing the center bolt to penetrate therethrough and the lower end of the same is formed into a folded end adapted to catch the lower edge of the special washer. This makes it possible to assemble the reflector attaching bracket without making any changes in a conventional brake unit, front fork and frame.