A simplified road bicycle frame mechanical design tool

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024)

Taking an engineering-based approach to bicycle frame design is a complex endeavour. While a bicycle frame may appear to be a simple structure to the uninformed, its mechanical design has proved to be complicated as an engineering structure, involving knowledge of a wide range of engineering disciplines and this remains an active field of engineering research. Bicycle designers not only need to account for static load conditions, but also for the fatigue life of the structure associated with the dynamic loads it is subject to. In addition, a working knowledge of relevant standards (e.g. ISO 4210-6 [1]) is a key requirement when designing bicycles. Numerical mechanical engineering design and analysis tools (e.g. CAD, FEA) are often required to support an engineering-based design process. They require a general mechanical engineering knowledge and also a specific knowledge in mechanics of materials to make intelligent usage of them and the results they generate. These tools can also be expensive and require suitable computer hardware to match. There is a wide array of options and technical settings available (e.g. different FEA solvers to chose from) and therefore such tools typically require a significant time investment in initial training to learn how to use them in addition to years of hands-on experience to understand how to second-guess them. According to a recent survey we distributed to professional frame designers/builders, this makes these tools fundamentally out of reach for those who may not have expertise, time, or money to make good use of them. Simpler, more accessible and user friendly design tools may prove helpful to introduce these tools to support bicycle frame designers/builders. The aim of this study therefore is to develop a simplified, open-access bicycle frame mechanical design approach to assess tube loads and guide frame designers/builders toward better designs by informing design decisions related to tube selection and frame geometry. This work was conceived as a work package in The Steel Bicycle Project to raise awareness of engineering principles that relate to steel bicycle frames and aims to support frame builders in designing and fabricating better and safer products.