Abstract: The invention relates to a freewheel hub for a bicycle including an axle and housing rotatably mounted thereon. A sprocket arrangement is mounted on the hub axle and a freewheel is arranged between the hub and the sprocket arrangement. The freewheel has a first coupling ring which couples to the hub and a second coupling ring which couples to the sprocket arrangement. The first and second coupling rings have respective tooth systems facing one another which are arrangeable into and out of mutual torque-transmitting engagement.

Abstract: A dual electric driving device, comprising: a main driving motor including a driving rotary shaft, with a shifting transmission gear being mounted on the front end of the driving rotary shaft; an outputting module being correspondingly mounted on the shifting transmission gear, the outputting module including a shifting driving shaft being rotatable by a driving force of the shifting transmission gear; a clutching and speed reducing driving device being correspondingly sleeved onto the back end of the driving rotary shaft of the main driving motor and coaxially rotatable by being engaged with the driving rotary shaft in one single direction; and an accessory driving motor including a driving shaft, the driving shaft being correspondingly mounted through the clutching and speed reducing driving device, and further being able to push the driving rotary shaft in one single direction to rotate by driving the clutching and speed reducing driving device.