Hub unit for use in electrically movable wheels and vehicle comprising the hub unit

A hub unit wherein the axis is prevented from deflecting for use in electrically assisted bicycles. A single fixing support shaft (57) has opposite ends projecting outward respectively from opposite ends of a hub (7) enclosing a motor (9) and a planetary gear reduction mechanism (6) therein and having inner teeth (66a) in mesh with planetary gears (65). The rotor (4) of the motor (9) has a tubular rotating shaft (44) rotatably fitted around the support shaft (57) and is therefore rotatable free of deflection of its axis relative to the support shaft (57). The hub unit is more simplified in construction and easier to assemble than the conventional hub unit wherein the rotating shaft of the rotor (4) is separate from the support shaft (57).