Freewheel adjustable wheel and fitness bike therewith

A fitness bike comprising:

• a frame unit supporting a saddle and a handle;
• a pedal unit provided in a rotating disc disposed on a lateral surface of the frame unit;
• a rotating gear rotated by a power transmitted from the pedal unit, and rotatably coupled to an outer surface of a shaft and having a spline gear disposed on an outer surface;
• a fixing case rotatably supporting the rotating gear, the fixing case of which rotation is restricted
• a inner case mounted inside the fixing case;
• a clutch bearing disposed between the rotating gear and the inner case and transmitting power when the rotating gear is rotated in a forward direction;
• a first gear having a shape having one side fixed to the inner case and the other side surrounding an outer surface of the clutch bearing, and receiving power through the clutch bearing;
• a drive unit fixed to the fixing case and supplying rotation power;
• a moving gear moved by power of the drive unit and operated in a non-freewheel mode of being engaged with the first gear and a freewheel mode of being spaced apart from the first gear;
• a gear position adjusting unit disposed in each of the first gear and the moving gear, and adjusting a position at which the first gear and the moving gear are engaged with each other by a magnetic force;
• and
• a protrusion detecting sensor disposed in the fixing case and detecting movement of the moving gear.