A bicycle front derailleur is basically provided with a base member, a chain guide and a chain restricting abutment. The base member is configured to be mounted on a bicycle frame. The chain guide is configured to be movably coupled to the base member between a retracted position and an extended position to move a bicycle chain. The chain restricting abutment is configured to restrict the bicycle chain from moving in a radially outward direction of a rotational center axis of a bicycle front sprocket when the base member is mounted on the bicycle frame and the chain guide moves from the extended position toward the retracted position.

A bicycle front derailleur is basically provided with a base member, a chain guide and a chain restricting abutment. The base member is configured to be mounted on a bicycle frame. The chain guide is configured to be movably coupled to the base member between a retracted position and an extended position to move a bicycle chain. The chain restricting abutment is configured to restrict the bicycle chain from moving in a radially outward direction of a rotational center axis of a bicycle front sprocket when the base member is mounted on the bicycle frame and the chain guide moves from the extended position toward the retracted position.

An electric front derailleur includes a base member, a chain guide, a first link member, a second link member and an electric driving unit. The base member includes a mounting portion to be operatively mounted to a bicycle frame. The chain guide is movable with respect to the base member. The first link member movably connects the chain guide to the base member. The first link member is at least partially aligned with the chain guide in a lateral direction with the electric front derailleur in an installed position. The second link member movably connects the chain guide to the base member. The second link member is at least partially aligned with the chain guide in the lateral direction with the electric front derailleur in the installed position. The electric driving unit is operatively coupled to the chain guide to move the chain guide with respect to the base member.

A bicycle derailleur comprises a base member, a linkage structure, and a motor unit. The linkage structure includes a first link pin rotatably mounted to the base member about a first pivot axis. The motor unit is configured to apply rotational force to the first link pin to rotate the first link pin relative to the base member about the first pivot axis.

A bicycle derailleur comprises a base member, a linkage structure, and a motor unit. The linkage structure includes a first link pin rotatably mounted to the base member about a first pivot axis. The motor unit is configured to apply rotational force to the first link pin to rotate the first link pin relative to the base member about the first pivot axis.

A front derailleur comprises a base member, a chain guide, and a linkage structure. The base member includes a mounting hole. The mounting hole has a center axis. The linkage structure comprises a first link member and a second link member. The first link member is pivotally coupled to the base member about a first pivot axis. The second link member is pivotally coupled to the base member about a second pivot axis. The first link member is pivotally coupled to the chain guide about a third pivot axis. The second link member is pivotally coupled to the chain guide about a fourth pivot axis. At least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis are non-parallel to and non-perpendicular to the center axis of the mounting hole.

A front derailleur comprises a base member, a chain guide, and a linkage structure. The base member includes a mounting hole. The mounting hole has a center axis. The linkage structure comprises a first link member and a second link member. The first link member is pivotally coupled to the base member about a first pivot axis. The second link member is pivotally coupled to the base member about a second pivot axis. The first link member is pivotally coupled to the chain guide about a third pivot axis. The second link member is pivotally coupled to the chain guide about a fourth pivot axis. At least three of the first pivot axis, the second pivot axis, the third pivot axis, and the fourth pivot axis are non-parallel to and non-perpendicular to the center axis of the mounting hole.

An electric front derailleur is basically provided with a base, a chain guide, a linkage and an electric motor unit. The base is configured to be mounted to a bicycle. The chain guide is configured to guide a chain. The linkage movably couples the chain guide to the base in a forward-rearward direction to move the chain guide between a retracted position and an extended position in a mounted state where the base is mounted to the bicycle. The electric motor unit is supported on the base and operatively coupled to the linkage to move the chain guide between the retracted position and the extended position. The electric motor unit is arranged at least partly closer to the bicycle than the chain guide.

An electric front derailleur is basically provided with a base, a chain guide, a linkage and an electric motor unit. The base is configured to be mounted to a bicycle. The chain guide is configured to guide a chain. The linkage movably couples the chain guide to the base in a forward-rearward direction to move the chain guide between a retracted position and an extended position in a mounted state where the base is mounted to the bicycle. The electric motor unit is supported on the base and operatively coupled to the linkage to move the chain guide between the retracted position and the extended position. The electric motor unit is arranged at least partly closer to the bicycle than the chain guide.

A drive train comprises a sprocket arrangement and a force-transmission coefficient. The sprocket arrangement includes a plurality of rear sprockets and a plurality of gear ratios respectively corresponding to the plurality of rear sprockets. The plurality of gear ratios includes a largest gear ratio and a smallest gear ratio. The sprocket arrangement includes at least one individual sprocket-space provided between two adjacent rear sprockets among the plurality of rear sprockets. The force-transmission coefficient is obtained by dividing a total gear range quotient by a total number of the at least one individual sprocket-space. The force-transmission coefficient is equal to or larger than 0.97 and is equal to or smaller than 1.36. The total gear range quotient is obtained by dividing the largest gear ratio by the smallest gear ratio.