Duratec's Lightweight, Composite Carbon Fiber Street Racing Bicycle Frame Development

• Functional Applications - Manufacturing Execution Systems (MES)
• Networks & Connectivity - Ethernet

• Life Sciences
• Plastics

• Procurement
• Product Research & Development

• Additive Manufacturing
• Manufacturing Process Simulation

Duratec, a Czech company known for its innovative handmade bike frames, was faced with the challenge of developing and optimizing a lightweight composite racing bike frame. The main objective was to create a world-class performance bike frame by minimizing mass while maintaining or increasing stiffness and strength. The bike frame, being the backbone of a reliable bike, had to be made with high-strength, high-modularity fibers laminated with the best resin. The challenge was further complicated by the need to comply with European standard EN 14781, which specifies performance and safety measures requirements. The Computer Aided Engineering (CAE) department at Advanced Engineering, Altair’s channel partner in the Czech Republic, had to optimize layer stacking and the number of plies necessary to meet all structural targets.

Duratec Ltd., founded in 1992 by Milan Duchek, is a Czech company known for its innovative handmade bike frames. The company was established as a result of Duchek's enthusiasm for handmade bike parts. Duratec develops bike frames using both aluminium and composite materials, with a focus on individualized approach to their customers by providing unique bike parameters for rider satisfaction. The company's objective is to develop the best possible bike suited to customer expectations, with detailed attention provided to obtaining correct size, frame geometry and optimized seat positioning. Duratec also participates in collaborative efforts such as sponsorship of Czech Paralympic racer Jiri Jezek, a multiple gold-medal winner of four Paralympic Games.

To address the challenge, Duratec utilized the Altair HyperWorks suite for a three-stage optimization process. The model was created in Altair HyperMesh, optimized using Altair OptiStruct, and the results evaluated using Altair HyperView. The first stage involved Free-Size Optimization, where the optimum shape and location of each composite material layer were defined. The second stage was Size Optimization, where the optimum thickness of the ply-patches were determined. The final stage was Shuffle Optimization, which evaluated the possible stacking sequence of the composite layers and suggested the ideal order to meet the desired design characteristics. Duratec also used a unique manufacturing technology, OnePiece Technology - 100% monocoque, which allowed the entire frame to be produced as a whole, including tube connections, in one thermal process. This technology ensured the highest manufacturing precision and maximum processing quality.

• The optimized bike frame developed by Duratec not only met the structural targets but also achieved world-class performance. The use of Altair HyperWorks suite for the three-stage optimization process ensured that the frame was optimized to minimize mass while improving stiffness and strength. The unique manufacturing technology, OnePiece Technology - 100% monocoque, ensured the highest manufacturing precision and maximum processing quality. The frame was not assembled and glued from multiple parts, which allowed the use of AFCF technology (Accurately Fitted Continuous Fiber) for fiber lay-up. This technology aimed to keep the fiber uninterrupted in the areas of highest stresses to maximize its mechanical properties, thereby achieving the limit parameters of stiffness and strength together with very low weight.

• A lightweight frame exhibiting all necessary strength requirements
• Mass reduction of 28% from the original weight
• The new bike frame without painting, stickers, metal joints etc., weighs 590g