Victoria Rojas
Sheet 5 of 5
USC Recumbent Vehicle Design Team Vice President and Drivetrain Lead Jan 2025 – present ASME Human Powered Vehicle Challenge

Recumbent vehicle drivetrain

Drivetrain design for USC’s entry in the ASME Human Powered Vehicle Challenge: aluminum idlers modeled in CAD, checked with FEA on the key load cases, and built in-house by machining, MIG/TIG welding and composite layup.

1stDesign, ASME eHPVC, 2025 and 2026
2ndOverall, 2026
Best InnovationAward, 2025
20Engineers coordinated across three subsystems

Take it apart

Spin the idler on its axle or pull the assembly apart to see the bracket, bearings and axle.

Simplified stand-in geometry. The exported CAD assembly replaces it once it’s ready.

My role

I lead drivetrain design and, as vice president, coordinate 20 engineers across the drivetrain, mechanical and electrical subsystems through to national competition. In my first year I also designed the vehicle’s telemetry PCB in KiCad.

Victoria: the drivetrain layout (gear range, chain path, why idlers), and the decisions you made versus the team.

Design and analysis

I modeled the aluminum idlers in CAD and ran FEA on the key load cases before committing to manufacture.

Victoria: which load cases, the resulting stress and safety factor, and any mass you saved.

FEA: idler under peak chain load
Stress under the governing load case.
CAD: drivetrain layout
Chain path from crank to rear wheel.

Manufacturing

We built the drivetrain in-house: machined idlers, MIG and TIG welded mounts, and composite parts laid up by the team.

Victoria: photos from the shop and the competition, and what you would change next year.

Photo: machined idlers
Finished idlers before assembly.
The USC recumbent vehicle team with their vehicle at ASME eHPVC
The team and vehicle at ASME eHPVC.