These carbon fiber components were designed and fabricated for use on a 2-person human-powered vehicle to compete in NASA’s 2018 Human Rover Exploration Challenge.
This annual off-road race draws hundreds of teams from around the world. Weighing in at 99 pounds fully equipped, our vehicle was the lightest overall at the competition by a margin of over 50 pounds.
Final wheel design:
Our team sought to improve upon previous designs to achieve a lighter, stiffer wheel that minimized issues with impact steering, rolling resistance, and lack of stiffness in previous versions.
Starting with half-scale prototypes, we developed a form to minimize weight and maximize lateral stiffness (A notorious weakness of bicycle wheels). The design path was chosen from a variety of concept models considered by the team. The final design was reached through iterative prototyping.
Each 28" wheel weighs in at about 7lb (with tread), and supports over 200lb directly lateral to the hub, and far more axially.
Process models and fabrication:
Final seat design:
Full-scale foam fit models were developed to find a comfortable seating solution.
The fabrication of the seat posed a unique set of challenges. The seat is essentially a 12"+ lever which encounters immense force from the riders--especially when pedaling up inclines. As with the wheel, through several iterations of trial carbon layup schedules (this time at full scale), we arrived at an ideal layup schedule that was strong where it needed to be, and reduced as much as possible in other areas.

The final product weighs about 1 pound.
Forming the final mold pattern:
The 2018 Rover in testing:
At the competition:
The Rover performed well at the April 2018 competition, and was a strong contender for first place. Unfortunately, near the end of the first day's race, the vehicle experienced a rod-end fracture. Although the failed joint was quickly replaced with upgraded hardware, the second race day was cancelled due to inclement weather. 
Check back next year for updated results!
My primary responsibilities on this project included design and fabrication of wheel, tread, seat, fender and leaf spring components. Other contributions included design and fabrication of the center folding latch, crank "reaction lever" mounts for our internally geared cranksets, front and rear steering arms/handlebars, seat belt mounts, chassis brazing/welding, and more.
The chassis was designed by Ryan Smith and Adrian Roop with faculty advisers Jim Pelto and Michael Lye.

other work