Patent ID: 7318784

Claim:
A bicycle rear derailleur, which is mounted on a bicycle frame so as to selectively derail the chain resting upon any of a multiple number of sprockets mounted on a rear hub axis, which is equipped with a base component, which is mounted onto the aforementioned frame; a link mechanism, one end of which is mounted on the aforementioned base component; a movable component, which is mounted on an other end of the aforementioned link mechanism, and which can be relatively displaced from the aforementioned base component; an outer plate, which is pivotally mounted on the aforementioned movable component; an inner plate, which is installed so as to face the aforementioned outer plate; a guide pulley, which is mounted onto a portion on one edge of the aforementioned plates, between the aforementioned plates, so as to freely rotate and move in the axial direction, and which can be engaged by means of the aforementioned chain; a tension pulley, which can be engaged with the aforementioned chain, and which is mounted onto a portion on another edge of the aforementioned plates between the aforementioned plates so as to freely rotate; wherein the inner plate includes a chain return section and a portion away from the chain return section, wherein the aforementioned chain return section is structured by a protrusion which is formed thicker than the portion of the inner plate away from the chain return section.