Mulliner, Bentley’s now in-house coach build specialists, have come up with the world’s largest full carbon fibre alloy wheel, at 22 inches in diameter. Developed for the Bentley Bentayga SUV, the wheel cuts six kilogrammes of unsprung weight from each corner of the car for overall huge weight savings (relative to the SUV’s 2.4-tonne kerb weight) and handling/agility advantages, over the standard alloy wheels available for the Bentayga. But more impressively, the carbon fibre wheel is the first of its kind to fully pass all the stringent tests of the German TÜV (Technischer Überwachungsverei – Technical Inspection Association), including impact tests.
In conditions that would otherwise shatter an aluminium alloy wheel and cause an explosive tyre burst, the Mulliner-developed carbon fibre wheel allowed for a slow deflation thanks to the carbon fibre weaves splintering off. In contrast, the wheel still retained its structure.
The wheel has been in development for five years in association with specialists Bucci Composites. Apart from the weight savings of carbon fibre, any decrease in any unsprung mass (including the wheels, tyres, braking system) supported by the suspension leads to bigger advantages in increased steering agility. Carbonfibre wheels also bring less wheel flex, lower tyre wear and increased stability to the table.
The wheels are created through a patented process that involves Resin Transfer Moulding, which involves stacking prescribed carbon fibre strips upon each other, placing them in moulds to create 3D preforms, before resin and hardeners are injected into the mould and cured for the final product, which is then polished to the finish you see.