The XK140 uses 5.5J" x 16" 72 spoke wire wheels. They were custom built by the Motor Wheel Service Workshop specifically for this application, using an aluminium rim and stainless steel centre and spokes. The aluminium rim is built around a vintage style hub, to remain true to the original style of the Jaguar XK series. The lacing pattern has been upgraded to include 72 stainless steel spokes. This differs from the original 60 spoke pattern, but gives valuable added strength to the wheel for the stresses of racing. With stainless steel the added weight of 12 spokes is not as drastic as a chromed carbon steel alternative, so the overall weight is reduced by 3kg per wheel, compared to the original chrome wheel.
The weight reduction is very important for racing as it not only reduces the overall weight of the car, therefore improving power to weight ratio, it has a very significant effect on the un-sprung weight of the vehicle which greatly improves the handling and braking performance of the car.
The wheels have certainly stood up to the stresses imposed on them during racing and halfway through each race season they are taken back to Dan Cooksley (The MWS Workshop Manager) to check them and they have always proved to be strong and durable.
The race regulations dictate the use of Dunlop L Section racing tyres for competition use. These tyres are suited to a slightly wider rim then a standard road tyre. Therefore the vehicle uses 5½" wide rims so that a 6.00 L section can be fitted, optimising the tyre's contact with the road.