Challenge

The client needed an ultralight road bike frame (< 850 g) that maintained lateral stiffness above 120 N/mm and met ISO 4210 fatigue standards. The design had to be suitable for series production using TIG welding processes and subsequent heat treatments.

Approach

A parametric analysis was performed using finite element analysis (FEA) varying wall thicknesses in 6061-T6 and 7075-T6 alloy tubes. 12 geometric configurations were evaluated, prioritizing material distribution in the highest stress areas (head tube junction, bottom bracket, and stays).

Implementation

Parametric CAD models were generated in SolidWorks and exported to Abaqus for nonlinear simulation. The profile of the top tube and seat tube was optimized, reducing thickness in low-stress areas and adding internal reinforcements at the bottom bracket. Validation was performed with 3D printed prototypes (PLA) to verify tolerance fits.

Result

The final frame weighed 832 g, with a lateral stiffness of 128 N/mm and a torsional stiffness of 68 Nm/degree. It exceeded fatigue tests by 15% above the standard. Manufacturing cost was reduced by 12% compared to the client's initial solution, thanks to material and welding process optimization.