Abstract: A transmission device is provided for bodybuilding devices or bicycles, including an axle that is operatively coupled to a sprocket assembly for collaborative operation. Two cranks are provided, having contact surfaces including one way bearing mounted thereto for fitting to two ends of the axle. Two clutch control assemblies are controllable through a wire control assembly such that the clutch control assemblies are selectively engageable with or disengageable from two cranks respectively to set the cranks in an operation mode of regular bicycle pedaling or an operation mode of one side pedaling alone or two side parallel pedaling. An important feature is that the wire control assembly is of an arrangement involving a mateable combination of two halves of which the parts are made of plastics, where assembly for centering is achieved with recess-projection engagement for better assembly accuracy.

Abstract: A transmission device is provided for bodybuilding devices or bicycles, including an axle that is operatively coupled to a sprocket assembly for collaborative operation. Two cranks are provided, having contact surfaces including one way bearing mounted thereto for fitting to two ends of the axle. Two clutch control assemblies are controllable through a wire control assembly such that the clutch control assemblies are selectively engageable with or disengageable from two cranks respectively to set the cranks in an operation mode of regular bicycle pedaling or an operation mode of one side pedaling alone or two side parallel pedaling. An important feature is that the wire control assembly is of an arrangement involving a mateable combination of two halves of which the parts are made of plastics, where assembly for centering is achieved with recess-projection engagement for better assembly accuracy.