PURPOSE: To improve durability by absorbing vibration or abnormal sound as well as to eliminate blinking of a lamp in the low speed traveling of a hub generator for a bicycle.

CONSTITUTION: In a hub housed generator, rings 20, 21 divided into right and left parts are provided on the inner periphery of a fixed cylinder body 7 fixed to an axle 2 so as to be rotated together with the fixed cylinder body 7. A planetary roller 24 to be joined on the inner peripheral surfaces of these rings 20, 21 and also to be joined to a sun roller 15 integrally formed together with a rotor 16 is pivotally supported to a carrier 5 integrated with a hub body 4. A ring-like damper 27 made of elastic material is interposed between the pivotal supporting shaft 25 of this planetary roller 24 and the planetary roller 24.