Cooper E-Cycles
Designing frames for electric NYC commuter bikes
Company/ Client
Cooper Union Estuardo Rhodas
Role
Frame Lead
Skills
2D & 3D Design Subtractive Manufacturing Finite Element Analysis Material Selection
Tools
Band Saw Water Jet Cutter Metal Laser Cutter
Duration
2022-2023
Overview
This project aims to design and manufacture a durable and accessible electric commuter bike for NYC, focusing on the frame, saddle, and wheels. The final design incorporates design specifications for comfort, weight, cost, stability, and aesthetics.
How could I design a bike without knowing how to ride one? 🫣
Embark on my journey of designing and learning to love bikes through a design project!
Motivations
The motivation for the bike frame is to build an aesthetic and structurally strong base that can seamlessly house driver controls and power train components. The frame consists of the head tube, down tube, top tube, seat tube, seat stay, chain stay, and drop outs. The goal is to design and build an electric bike that can carry a 300 lb payload and sustain the new york city road conditions while maintaining rider comfort and ease of riding while remaining under 40lbs.
The frame design optimizes weight, rigidity, and aesthetics to cater to New York City commuters as an alternative for bulky, heavy, and uncomfortable rental options.
To address the function requirements challenges, I took the following approach:
BikeCAD 2D sketching: using open-source bike design software to analyze angles, lengths, and standard dimensions on existing bikes. I used these models to generate 2D bike designs
Literature Review: reading on the methods by which bike designers and manufacturers use to ensure comfortable riding design
3D Design: designing in Fusion360 and Solidworks collaborative to ensure cohesion to final product assembly.
ANSYS Simulation: validating functional requirements on design iterations to ensure that the designs can withstand varying NYC road loading conditions including curbs, pedaling, accidents, and more.
Manufacturing: consulting shop techs to understand what is feasible design for welding and notching. I used the water jet cutter to cut thicker sheets for dropouts and converted 3D sketches to manufacturing plans for welders
Reflections
This final design is an iteration of the previous design as it includes efforts to simplify manufacturing and reduce costs. The first version of this design included more aggressive angles, lengths that were not contiguous with other sub-system components, and unique tube shapes that required more difficult manufacturing processes. The Cooper E-Cycle is built on reusing bike tubes that were abandoned in 41 Cooper Square.
The bike design was built over two semesters. The first semester was dedicated to design justifications and the second semester was dedicated to manufacturing and validation.
The frame team delivered a robust frame for the battery team and Cooper Union End of Year show. The parts were assembled with minor adjustments for fittings.
