Bicycle derailleur, bicycle gear structure, bicycle motor unit, and front derailleur

A bicycle gear structure comprising:

• a torque diode comprising:
• an outer casing;
• a first shaft rotatably mounted to the outer casing about a first rotational axis;
• and
• a second shaft rotatably mounted to the outer casing about a second rotational axis;
• a first transmitting gear attached to the first shaft;
• and
• a first additional transmitting gear meshed with the first transmitting gear and rotatably mounted to the outer casing about a third rotational axis offset from the first rotational axis and the second rotational axis.

A front derailleur comprising:

• a base member;
• a chain guide movable relative to the base member;
• a linkage structure configured to movably couple the chain guide to the base member;
• and
• a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:
• a motor configured to generate the rotational force;
• and
• a gear structure including a plurality of spur gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure, the motor unit being free of gears other than the plurality of spur gears on a rotational-force transmission path provided from the motor to the at least one of the chain guide and the linkage structure.

A bicycle derailleur comprising:

• a base member;
• a chain guide movable relative to the base member;
• a linkage structure configured to movably couple the chain guide to the base member;
• and
• a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:
• a motor;
• and
• a gear structure including a plurality of spur gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure, the gear structure having a reduction ratio equal to or lower than 1400.

A front derailleur comprising:

• a base member;
• a chain guide movable relative to the base member;
• a linkage structure configured to movably couple the chain guide to the base member;
• and
• a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:
• a motor configured to generate the rotational force;
• a gear structure including a plurality of gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure;
• and
• a gear support structure configured to rotatably support the plurality of gears,
• the plurality of gears comprising:
• a first gear rotatable relative to the gear support structure about a first gear axis;
• a second gear rotatable relative to the gear support structure about a second gear axis;
• a third gear rotatable relative to the gear support structure about a third gear axis;
• a first pin configured to rotatably support the first gear about the first gear axis, the first pin including a first pin end and a first opposite pin end;
• a second pin configured to rotatably support the second gear about the second gear axis, the second pin including a second pin end and a second opposite pin end;
• a third pin configured to rotatably support the third gear about the third gear axis, the third pin including a third pin end and a third opposite pin end, and
• the gear support structure comprising:
• a first support configured to support the first pin end and the second pin end;
• a second support configured to support the second opposite pin end and the third pin end, the second support being a separate member from the first support;
• a third support configured to support the third opposite pin end;
• and
• a fourth support configured to support the first opposite pin end.