Design and Construction of an Electric Motorcycle

Abstract

Engineering students at James Madison University are creating an all-electric motorcycle as part of a two-year capstone design project. The final product will be an educational system that promotes access to the electric powertrain (consisting of tractive battery pack, battery management system (BMS), motor controller, and motor). This paper focuses on development of system performance parameters, design of major components including chassis and battery pack/BMS enclosure, and signal interactions between powertrain components. Previous iterations of electric motorcycle conversions developed at JMU were constrained by the donor chassis which were designed for support of internal combustion engines. Although teams worked to optimize the fitment of powertrain components within existing frame members, compromises were necessary. Other limitations of previous iterations include battery pack discharge rates and delicate battery management systems. Although electric motorcycles are commercially available, their powertrain components are generally proprietary and inaccessible (not available for hacking or other educationally appropriate activities). The current iteration was developed to address these limitations. Results include benchmarking results, estimation of performance, and physical iterations of design choices. The final iteration of the modular battery pack, designed for student interaction, consists of seven sub-pack modules with visible and intuitive wire routing. The completed powertrain is designed to favor accessibility of components as well as optimize available space within the frame while closely matching the center of gravity and suspension as well as steering capabilities of the donor motorcycle.