Time for a change of guard in the bicycle sector!


PHOTO: A new continuous fibre-reinforced thermoplastic composite (CFRTP) from Covestro is pushing boundaries. It can easily be manufactured in large quantities and is not brittle – unlike conventional synthetic resin composites

RESTRICTIONS on synthetic resin composites, such as the mass production capability and intrinsic brittleness of the material, could soon be a thing of the past thanks to Covestro’s new lightweight CFRTP composites (continuous fibre-reinforced thermoplastic). The impact-resistant matrix material polycarbonate further increases safety – and the popular carbon look is also included. CFRTP composites also increase the cost-effectiveness of production.

Experienced developer, Dr Niccolo Pini, founder and managing director of Next Composites GmbH in Otelfingen, Switzerland (a company of Ensinger GmbH), has kept up with the latest materials that the market offers. His latest highlight is a pedal crank made of CFRTP, the new high-performance composites in Covestro's portfolio. The part is not only extremely light and robust, but also looks great due to the carbon fibre optic. Thanks to the new manufacturing possibilities of Next Composites, it can be reproducibly and automatically produced – with all the advantages for component quality.

Covestro CFRTPs – continuous carbon fibres impregnated with the high-performance plastic polycarbonate - offer enormous strengths thanks to the fibre reinforcement, but thanks to its thermoplastic matrix, it can also be processed mechanically and significantly faster than epoxy-based systems

There are also considerable economic advantages in terms of post-treatment: traditionally manufactured composites made of synthetic resin and carbon fibre usually has to be laboriously treated with fillers, reground and polished in order to satisfy the aesthetic demands of the customers.

According to Pini, a ‘classic’ carbon frame passes through up to 70 pairs of hands in the course of its manufacture. Approximately 120 working hours are required to bring the component to the retailer – and half of this time is needed for rework. With Covestro CFRTP, the component has a high-quality surface finish and comes out of the machine practically ready for sale. And with a weight of 150 grams, the new crank is still incredibly light despite its load-bearing capacity.

The matrix material polycarbonate also offers clear advantages. Thermoset materials like those often used in the manufacture of carbon fibre composites tend are brittle and break easily, whereas polycarbonate is also able to withstand violent blows.

Another advantage is that the toughness of the plastic material means that metal inlays, which are commonplace with synthetic resin composites, can be largely dispensed with when processing Covestro's CFRTP tapes. Dr Pini and his colleagues simply cut their threads into the moulded crank – ready. At present, they only need a single inlay and that too should soon be a thing of the past.