Design and evaluation of a lightweight composite bicycle frame for enhanced performance

Thesis Abstract

The increasing demand for high-performance cycling equipment necessitates the development of lightweight, durable, and efficient bicycle frames that can enhance rider performance while maintaining structural integrity. Traditional steel and aluminum frames, though reliable, tend to be relatively heavy, limiting potential speed, agility, and energy efficiency, especially in competitive cycling contexts. This study aims to design and evaluate a novel composite bicycle frame fabricated from advanced fiber-reinforced polymer materials to achieve significant weight reduction without compromising strength and safety. The specific objectives include analyzing the mechanical properties of candidate composite materials, developing a detailed design model optimized for weight and structural performance, fabricating a prototype frame, and assessing its functional performance through quantitative testing. A mixed-method research design combining experimental and computational approaches was adopted to fulfill these objectives. The population consisted of composite material samples and bicycle frame prototypes manufactured during the study period. A total of 60 samples of carbon fiber-reinforced epoxy composites, obtained from three different manufacturing batches, were tested for tensile, compressive, and flexural strength using a universal testing machine, following ASTM standards. A prototype frame was fabricated using vacuum-assisted resin transfer molding (VARTM), with the design optimized via finite element analysis (FEA) to ensure load-bearing capacity and ergonomic considerations. The sample size for the prototype testing comprised five fully assembled frames subject to standardized static load tests, fatigue cycling, and real-world riding evaluations. Data collection involved mechanical testing, structural inspections, and rider performance assessments. The validity and reliability of the testing instruments were confirmed through calibration and repeated measurements, while analytical techniques such as ANOVA and regression analysis were employed to compare material performances and identify influencing factors. The anticipated findings indicate that the optimized composite frame will weigh at least 25% less than traditional aluminum equivalents, with compressive and tensile strengths exceeding 600 MPa and flexural strength surpassing 900 MPa, meeting or exceeding industry safety standards. Structural analysis is expected to reveal uniform load distribution and excellent fatigue resistance, thus confirming the suitability of composite materials for high-performance bicycle frames. Moreover, rider performance evaluations are projected to demonstrate improvements in maneuverability, acceleration, and overall riding efficiency, attributable to the frame’s reduced mass and tailored geometry. This study advances knowledge by providing a comprehensive framework for the integration of advanced composite materials into bicycle frame design, supported by empirical data demonstrating improved mechanical performance and functional advantages. It contributes to the existing body of sports engineering and materials science literature by linking material properties, structural design, and real-world application, thus offering a model for future lightweight vehicle structures. The research also incorporates relevant theories, including the materials selection theory for composite optimization and the principles of finite element structural analysis, to inform design decisions and performance evaluation. In conclusion, the study affirms that carefully engineered composite bicycle frames can significantly outperform traditional counterparts in weight, strength, and ride quality. The findings recommend adopting such materials and design methodologies in high-performance cycling and recreational applications. Further research should explore long-term durability under varied environmental conditions, cost-benefit analysis relative to traditional materials, and the potential for scalable manufacturing processes. Overall, this research offers a strategic pathway toward more efficient, lightweight cycling infrastructure that can have broader implications for transportation and sports industry innovations.