Bicycle derailleur

1. A bicycle derailleur comprising:

a base member configured to rotate together with a bicycle sprocket apparatus about a rotational axis of the bicycle sprocket apparatus, the base member being configured to be mounted a sprocket body of the bicycle sprocket apparatus;

a movable member movable relative to the base member to displace a bicycle chain; and

an electric actuator configured to electrically actuate the movable member.

2. The bicycle derailleur according to claim 1 , wherein

the movable member protrudes from the base member in a radially outward direction with respect to the rotational axis in a mounted state where the bicycle derailleur is mounted to the bicycle sprocket apparatus.

3. The bicycle derailleur according to claim 2 , wherein

the movable member is configured to be disposed radially outward from sprocket teeth of the bicycle sprocket apparatus in the mounted state.

4. The bicycle derailleur according; to claim 1 , wherein

the movable member is pivotally arranged about a pivot axis with respect to the base member.

5. The bicycle derailleur according to claim 4 , wherein

the pivot axis is perpendicular to the rotational axis.

6. The bicycle derailleur according to claim 5 , wherein

the pivot axis extends in a tangential direction with respect to a circle centered on the rotational axis in a mounted state where the bicycle derailleur is mounted to the bicycle sprocket apparatus.

7. The bicycle derailleur according to claim 1 , wherein

the movable member is movably arranged between a first position and a second position in an axial direction that is parallel to the rotational axis in a mounted state where the bicycle derailleur is mounted to the bicycle sprocket apparatus, the first position being different from the second position.

8. The bicycle derailleur according to claim 7 , wherein

the first position corresponding to an upshifting operation and a second position corresponding to a downshifting operation.

9. The bicycle derailleur according to claim 7 , further comprising

a controller configured to control the electric actuator to selectively move the movable member toward one of the first position and the second position in accordance with an input signal.

10. The bicycle derailleur according to claim 9 , wherein

the controller is configured to control the electric actuator to move the movable member toward the one of the first position and the second position only within a predetermined rotational angle of the bicycle sprocket apparatus about the rotational axis.

11. The bicycle derailleur according to claim 9 , wherein

the controller is configured to control the electric actuator to maintain the movable member in the one of the first position and the second position.

12. The bicycle derailleur according to claim 9 , wherein

the controller is configured to maintain the movable member in the one of the first position and the second position until the controller receives the input signal to move the movable member toward the other of the first position and the second position.

13. The bicycle derailleur according to claim 9 , further comprising

a wireless receiver to receive the input signal for the controller to control movement of the movable member.

14. The bicycle derailleur according to claim 7 , wherein

the bicycle sprocket apparatus includes a first sprocket including a first sprocket body and a plurality of first sprocket teeth extending radially outward from the first sprocket body, and a second sprocket having a second sprocket body and a plurality of second sprocket teeth extending radially outward from the second sprocket body, a diameter of the second sprocket body being larger than a diameter of the first sprocket body, and

the first position is closer to a first rotational plane defined by the first sprocket teeth of the first sprocket than the second position with respect to the axial direction in the mounted state.

15. The bicycle derailleur according to claim 14 , wherein

the movable member intersects with the first rotational plane in the first position.

16. The bicycle derailleur according to claim 14 , wherein

the second position is closer to a second rotational plane defined by a second sprocket teeth of a second sprocket than the first position with respect to the axial direction in the mounted state.

17. The bicycle derailleur according to claim 16 , wherein

the movable member intersects with the second rotational plane in the second position.

18. The bicycle derailleur according to claim 1 , wherein

the electric actuator is positioned radially inward of the movable member with respect to the rotational axis in a mounted state where the bicycle derailleur mounted to the bicycle sprocket apparatus.

19. The bicycle derailleur according to claim 18 , wherein

the bicycle sprocket apparatus includes a bicycle crank assembly including a first sprocket, a second sprocket, a crank arm and a crank axle, and

the electric actuator is disposed on one of the crank arm and the crank axle.

20. The bicycle derailleur according to claim 1 , further comprising

a transmitting member to transmit a driving force from the electric actuator to the movable member.

21. The bicycle derailleur according to claim 20 , wherein

the transmitting member includes a flexible member.

22. The bicycle derailleur according to claim 1 , further comprising

a power supply to supply electricity to the electric actuator.

23. The bicycle derailleur according to claim 22 , wherein

the bicycle sprocket apparatus includes a bicycle crank assembly including a first sprocket, a second sprocket, a crank arm and a crank axle,

the power supply is configured to be disposed into the crank axle.