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 configured to be 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 of a rotation body of the rotating gear;
• a fixing case rotatably supporting the rotating gear while rotation of the rotating gear is restricted;
• an inner case mounted inside the fixing case;
• a clutch bearing disposed between the rotating gear and the inner case and configured to transmit power when the rotating gear is rotated in a forward direction;
• a first gear having a shape including a first side fixed to the inner case and a second side surrounding an outer surface of the clutch bearing, and configured to receive power through the clutch bearing;
• a drive unit fixed to the fixing case and configured to supply rotation power;
• a moving gear configured to be moved by the rotation 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 configured to adjust a position at which the first gear and the moving gear are engaged with each other by at least one magnetic force;
• and
• a protrusion detecting sensor disposed in the fixing case and configured to detect movement of the moving gear.