Development of a Spoke-Less Bicycle Wheel Housing the Entire Prime-Mover Assembly for an Electric Bicycle

Electric bicycles or E-bikes are the future of transportation and have the potential to change the daily commute scenario in urban areas. E-bikes can not only contribute towards an environmental-friendly commuting option but also promote a fitter community. One of the reasons limiting the use of E-bikes is their cost (both capital and operating). To reduce the cost of E-bikes, a system needs to be developed that would allow the easy conversion of any ordinary bicycle into an E-bike. This can be achieved by designing an external electric drivetrain or a prime-mover assembly that can be installed onto any bicycle without disrupting its mechanical transmission. This paper describes the development of a prototype which can be used for the conversion of any regular bicycle into an E-bike by replacing its front wheel. Since the front wheel is not an active member of the mechanical transmission and can be easily removed, it can house an entire prime-mover assembly. The front spoke-less wheel of the prototype houses a motor, a battery and two idler pulleys in a triangular formation. The rear transmission is left unchanged leaving the option of riding the bicycle with or without the electrical components. The power from the motor is directly transmitted to the inner rim of the front wheel using the friction-drive. The speed is controlled by a throttle integrated into the handlebar. The outcome of the development phase is the conversion of an ordinary bicycle into an E-bike that provides a stable riding experience with proper balancing of forces in the front wheel and optimum power availability for the rider.