BMW has won an innovation award for a prototype carbon-fibre swingarm that could pave the way for mass-produced and cheap carbon bike parts.
The firm took the 2018 JEC Innovation Award in the Leisure and Sports category for developing the swingarm. Although the firm hasn’t revealed details, it appears to fit the G310 series of bikes. The JEC Group is the world’s leading specialist organisation for the development and manufacture of composites.
While BMW has already revealed its first carbon-fibre production bike, the HP4 Race, it’s a very expensive, track-only machine. The new prototype carbon-fibre swingarm shows a very different approach. It uses carbon-reinforced plastic, with short strands of carbon instead of the usual sheets of the material. That means a high-speed, automated production facility can injection-mould the part for mass production. Carbon-fibre tape provides extra reinforcement.
What BMW says the carbon-fibre swingarm:
Project manager Elmar Jäger said: “We opted for chassis components under continuous load since the requirements involved are especially demanding. While car chassis parts are concealed, the visible motorcycle rear swinging arm was ideal for our project since the forces at work are immediately evident. Our production technique uses CFP in the form of high-strength endless fibres where this is required by the stress pattern, while an injection mould part with short CFP recycling fibres is used where the stress levels are not as high. In this way, we developed a cost-efficient design that can be scaled according to requirements by inserting endless fibres with varying levels of strength in the same tool. These were the points that impressed the international jury. The insights we gained from this motorcycle component are equally valuable from the point of view of car development and can be applied accordingly.”
Dr Joachim Starke accepted the award for BMW, saying: “In addition to achieving weight benefits and cutting costs significantly, we also managed to develop a technology that allows precise configuration of component properties by using a variety of composite and metal inserts.”
BMW already leads the way in carbon-fibre car manufacturing, with the mass-made i3 electric car. The new carbon-fibre swingarm is a ‘scaleable’ design that allows a single manufacturing tool to make a range of different components, with each taking less than a minute to create.
Starke added: “All this impacts significantly on cost efficiency (component costs) as well as part properties (strength and stiffness).
“With this example of the rear swinging arm, the project has allowed BMW Motorrad to take on a pioneering role within the motor vehicle industry. The insights gained consistently build on the BMW i3 as the basis for the use of CFP in serial production and include interesting aspects in terms of the future development of new BMW motorcycles and automobiles.”