UCI Bike Frame


UCI Bike Frame is a senior engineering project devoted to the design and manufacturing of bicycle frames. In the past, the project has functioned as a UROP grant-funded club and later a mechanical engineering senior project "UCI Bike Builders" (MAE 189). The club sought to develop a traditional steel lugged bike, so a modular welding jig was designed and machined in-house. The club is currently brazing this traditional steel bike using oxy-acetylene. The senior project is focused on developing an additively manufactured weldless bike that will utilize multiple materials. This bike is experimental in nature and allows for greater customization while also reducing assembly time. The bike will utilize off-the-shelf carbon tubes which will be connected using custom additively manufactured titanium lugs. The carbon tubes will be fixed to the lugs using a two-part epoxy and fishing wire will be wrapped around the ends of each tube to ensure concentricity at the mating surface. Tolerancing will be extremely important in determining the strength of the joint. The 3D-printed lugs will have to be post-processed in the machine shop to ensure accurate tolerancing.

UCI Bike Frame continues the work started in the original MAE 189 team and provides engineering students an opportunity to develop a system of mass-producing custom bikes that is cost-effective, sustainable, and time-efficient. Testing on completed frames will be conducted using industry-standard methods for bicycle frames. This involves fixturing the bike vertically and exerting a load on the front axle.


  • Manufacture and test a custom weldless bike frame by Winter 2022
  • Adhere to industry standards for frame tolerances and structural limits
  • Design a system of manufacturing with costs below industry averages
  • Organize documentation for future teams seamlessly expand off of previous work
  • Finish welding/brazing on the traditional steel frame


The team currently has a nearly completed, parametric front triangle design in CAD.  So far, the team has presented plans for an adaptive yoke and ran simulations for the chainstays needed to complete the rear triangle.

High Definition Photos

Full Sideview
Welding/Assembly Jig

Looking Forward

The team will balance precision/ testing with manufacturing progress by:

  • 3D print a section of the bottom bracket for testing
  • CNC mill out the prototype bottom bracket lug
  • Design, CNC, and test an adaptive yoke to fit chainstay tubes
  • Glue all pre-cut tubes and post-processed lugs together using the welding jig as a fixture for alignment
  • Fillet braze a rear triangle using an in-house, custom dropout design

Team Contacts

Trevor Tuck e. tuckt@uci.edu

Jacob Rider e. riderj@uci.edu

Catherine Zhang e. catheryz@uci.edu

Caden Ziegler e. cdziegle@uci.edu

Shivam Shah e. shivamns@uci.edu



Prof. Lorenzo Valdevit

Benjamin Dolan

Tyler Schuldt


Past MAE 189 Team Members

Felix Slothower e. fslothow@uci.edu

Tony Drabeck e. adrabeck@uci.edu

Trevor Tuck e. tuckt@uci.edu

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