Colloquia

Summary

In recent years, the e-bike has become indispensable and the demand has increased. However, the development of e-bike frames is lacking and facing some challenges. First, aluminium, which is widely used in the bicycle industry, is not particularly sustainable. Second, the increased demand for e-bikes requires scaling up production, but the current labour-intensive production process makes this hard to achieve. Finally, the production process results in unpredictable quality and limits the design possibilities. Innovations in material and manufacturing technologies are required to facilitate further growth.

For these reasons, Royal Dutch Gazelle is looking for alternatives to its current bicycle frame technology. The aim of the research is to investigate which alternative technologies and materials can improve the current frame design on the three innovation metrics. The main research question is: ‘’Taking into account the three drivers of innovation, how to develop an e-bike frame that improves on the current situation?’’. The three drivers of innovation are sustainability, supply chain flexibility, and product quality & design freedom.

To answer this question first a literature study on material and manufacturing processes has been conducted. From the material study, it was concluded that thermoplastic composites show the most potential with regard to the drivers. Thermoplastic composites boast outstanding structural characteristics and are increasingly valuable in sectors as a substitute for metal. They have the ability to melt, enabling high recyclability. The short cure times make them suitable for mass consumption. After a more extensive literature study on thermoplastic composites and their manufacturing processes, several bicycle frame concepts using different materials and production processes were composed. A decision model has been developed to score the different concepts. The decision model shows that a glass fibre thermoplastic composite combined with a water-assisted injection moulded production process is a promising combination. Water-Assisted Injection Moulding (WAIM) is a relatively new production process. It is a variation on conventional IM technology which provides a new way to fabricate hollow or other complicated products, making them suitable for the bicycle industry. Some advantages are the low cycle time, enabling further scaling up of the production process, and the automation of the production process resulting in more stable quality and more design freedom.