E-Bike Engagement and Accessibility [article]

Jonah Shifrin, Julia Stuart, Jake Horcher, Jorge Alfaro, University, My, Steven Skerlos
2021
There is currently a large barrier of entry to the design space surrounding a DIY E-bike retrofit build. The combination of necessary knowledge regarding gearing and transmission, mechatronics and motor control, battery charge and capacity, and force analyses, all in addition to general bike-related knowledge can be completely overwhelming to a novice user. Our team approached this project through a Socially-Engaged Design strategy to provide access, regardless of mechanical ability and budget,
more » ... to a low-cost and easily accessible E-bike. We defined requirements for our solution design to incentivize the use, purchase or build of E-bikes, to be usable without much background knowledge, to be safe, to be attractive and accessible to the user, and to be inexpensive. We began our design process by conducting research on existing designs solutions. From here, we conveyed every step that a user would go through to access an E-bike themselves and how they could optimize an E-bike or E-bike retrofit of their own. Our theoretical stakeholder persona for this project is a University of Michigan student looking to commute across campus daily. This persona helped us build specifications such as hill climb ability, battery life and a target max flat ground speed. Primary subsystems were identified as system controls like throttling or pedal assist, motor and transmission, power supply, and the mounting interface. Our final CAD model of this design and its subsystems includes the motor, power supply, transmission, housing, and interfaces for any other subsystem. We also developed a model for a sustainable modular battery prototype design. This accomplishes our aim to make each battery cell replaceable while achieving a high cycle life compared to other batteries of similar size and cost. The transmission design solution provides a smooth ride up the steepest Ann Arbor hills and its mounting design provides easy access for maintenance and diagnosability. After completing the design, we evaluated it against our set specification [...]
doi:10.7302/1179 fatcat:mmeikbs5lngmdb2utvjlxglfb4