Abstract: An apparatus for achieving the return of a chain to a rear derailleur tension pulley more easily by means of pedaling action when the chain falls off from the tension pulley is provided. The rear derailleur is equipped with a base component, a link mechanism, a movable component, Outer Plate 20, Inner Plate 21, Guide Pulley 22, Tension Pulley 23, and Chain Return Section 32. The base component is a component which is mounted on the frame. The link mechanism is a mechanism of which one end is mounted on the base component. The movable component is a component which is mounted on the other end of the link mechanism, and which can be relatively displaced from the base component. The outer plate is a component which is mounted on the movable component so as to undulate like a see-saw. The inner plate is a component which is installed so as to face the outer plate.

Abstract: An apparatus for achieving the return of a chain to a rear derailleur tension pulley more easily by means of pedaling action when the chain falls off from the tension pulley is provided. The rear derailleur is equipped with a base component, a link mechanism, a movable component, Outer Plate 20, Inner Plate 21, Guide Pulley 22, Tension Pulley 23, and Chain Return Section 32. The base component is a component which is mounted on the frame. The link mechanism is a mechanism of which one end is mounted on the base component. The movable component is a component which is mounted on the other end of the link mechanism, and which can be relatively displaced from the base component. The outer plate is a component which is mounted on the movable component so as to undulate like a see-saw. The inner plate is a component which is installed so as to face the outer plate.