Improvement proposal in the structural system of a15” R29 rigid mountain bike frame, with fea and geometric optimization

Currently, cycling has increased significantly, along with the implementation of mountain bikes (MTB) with rigid frames, which are employed both as a means of transportation and for competitions due to their affordable cost. Since these bikes serve various purposes, they present varying stresses on their frames, surpassing design requirements and leading to failures in the upper chainstays. This study analyzes this type of failure, for which information regarding the frame material, acting loads, and 3D modeling is collected. Subsequently, a failure homologation analysis is conducted, and a proposal for improvement is generated by applying geometric optimization, determining a thickness of 3.50 mm in the upper chainstays and guaranteeing the resistance of the bike frame under the study conditions; that is, a drop of 60 cm and a load of 74 kg. This modification ensures that the stress in the upper chainstays does not exceed the ultimate stress of the material of 890,94 MPa.