After years of collaboration with one of the world’s leading composite suppliers, Bentley has unveiled a new carbon fibre wheel for Bentayga luxury SUV.
Designed in partnership with renowned specialists Bucci Composites, the 22-inch carbon wheel will be the largest carbon wheel ever produced.It will offer a wide range of benefits beyond the initial 6 kg reduction in unsprung mass per wheel. It is the first carbon wheel ever created that has been subjected to the extremely rigorous testing standards.
It passed the most stringent testing for non-metallic wheels according to the TÜV (Technischer Überwachungsverei – Technical Inspection Association) standard, including biaxial stress testing, radial and lateral impact testing for simulating potholes and cobblestones, tyre overpressure, and a torque test that exceeded the permitted limits.
The impact test – one of the most severe tests of the TUV requirements – has demonstrated how the carbon rims are extremely safe as well as proving the benefits of performance. Thanks to layers of fibre weaves a carbon fibre wheel will generate a slow tyre deflation after a serious impact, as opposed to a wheel made of aluminium, which would cause an explosive tyre collapse. This allows the vehicle to stop safely after an impact.
In the final sign-off stage, the wheel was put to the test on one of the most famous tracks in the world – the Nürburgring Nordschleife.
The Technological Benefits of Composite Wheels
Carbon fibre not only provides a significant weight saving, but also offers the additional benefits of increased strength and stiffness. This leads to a number of fundamental benefits:
- Increased safety – when the rim receives a high impact, the weave pulls apart leaving openings to allow gradual air loss rather than instant deflation like an aluminium rim.
- Increased steering agility – the 6 kg weight saving and the high stiffness afforded by the properties of carbon fibre mean a more stable and consistent steering platform. In comparison, a forged aluminium rim can lose up to a degree of camber due to wheel flex, reducing grip and agility.
- Improved and more responsive braking thanks to the decrease in unsprung mass.
- Reduced tyre wear – Since the stiffer carbon rim does not suffer from the same amount of bending, it allows for greater tyre stability and a more consistent contact patch thanks to a larger tyre support surface.
Innovative Production Processes
One of the main innovations lies in the rim manufacturing process, which involves the application of innovative concepts (covered by patents) combined with the use of high pressure RTM (Resin Transfer Moulding). The materials and production parameters have been carefully studied to ensure the repeatability of the product without affecting its quality.
The process involves the cutting of carbon fibre cloth into prescribed shapes. The weave segments are then stacked, heated and draped into a mould to create three-dimensional preforms. The preforms are collated and arranged into a larger mould before resin and hardner is injected throughout. After curing time at temperature, the component assembly is removed from the mould, and the final surfaces are machined to the correct finish, before polishing.
New Mulliner Products for the Future
This collaboration with a world leading composites supplier underlines Mulliner’s key principle in offering Bentley’s customers new and unique features. The new 22” carbon wheel is the perfect complement to Bentley’s existing carbon fibre products, including the highly sought-after Styling Specification which adds a carbon front splitter, sill extensions and rear diffuser to the Bentayga, and the opton of high gloss carbon fibre veneer to the interior.
The new wheel will be available to order late 2021.
Bentley Mulliner 22-inch Carbon Fibre Wheel Images:
Source: Bentley Motors