Bicycle hub transmission

A bicycle hub transmission comprising:

• a hub axle;
• a driver rotatably supported relative to the hub axle;
• a hub shell rotatably supported relative to the driver,
• a power transmission mechanism including a downstream planetary gear unit and an upstream planetary gear unit, which are operatively disposed between the driver and the hub shell to selectively transmit rotational power from the driver to the hub shell through one a plurality of power transmission paths;
• and
• a shift mechanism operatively coupled to the power transmission mechanism to selecting one of the power transmission paths,
• the downstream planetary gear unit including a planetary gear carrier that meshes with planetary gears of the upstream planetary gear unit or with a linking member which is coupled to the planetary gears of the upstream planetary gear unit, and the planetary gear carrier of the downstream planetary gear unit being coupled with a brake unit to transmit a reverse rotational power from the driver to the brake unit.