A ten speed bicycle gear shift includes front and rear derailleurs actuated by a single continuous cable. Movement of the cable through a discrete given distance in one direction increases the gear ratio and movement of the cable through the same discrete given distance in an opposite direction decreases the gear ratio. First and second levers are mounted on the handlebar for easy manual stroking, operation of the first lever moving the cable through the discrete given distances in one direction and operation of the second lever moving the cable through the discrete given distances in an opposite direction. A marker on a portion of the cable can be visually observed relative to a fixed scale on the bicycle frame to indicate at all times the particular gear position. The gear shift is further characterized by cam arrangements for positively positioning the derailleurs in accordance with movement of the cable to selected positions.