Bicycle transmission system

A bicycle comprising:

• a frame;
• a first wheel and a second wheel attached to the frame;
• a first planetary member rotatably mounted to the frame;
• a ratchet integral with the first planetary member;
• a second planetary member rotatably mounted to the frame;
• a compound pawl movably disposed between the first planetary member and the second planetary member, the compound pawl having a base pawl member and a blocker pawl member, the blocker pawl member adapted to engage the ratchet to prevent a driven relative rotation of the first and second planetary members, and the base pawl member movably mounted to the second planetary member at a base joint and the blocker pawl member movably positioned with respect to the base pawl member at an articulation juncture, wherein the compound pawl stably provides blocking forces to oppose a load tending to cause the driven relative rotation when the blocker pawl member engages the ratchet and the relative configuration of the blocker pawl member and base pawl member at the articulation juncture is stable, thereby preventing the driven relative rotation;
• and a planetary shift actuator adapted to apply a force to the compound pawl to cause the relative configuration of the blocker pawl member and base pawl member to articulate into an unstable condition at the articulation juncture, thereby substantially releasing the blocking forces and allowing the driven relative rotation.