New production genuine Girling floating brake disc combines light weight with smoother vibration-free braking. Suitable for fitment to front or rear 1972-1975 Norton Commando disc brake hubs with the 5 hole bolt pattern.
The stainless steel floating brake disc rotor is mounted to the lightweight anodized aluminum alloy center carrier using steel riveted bobbins. The drilling pattern and cooling slots are designed for fitment to either the left or right side of the hub, making it ideal for dual-disc front brake conversions. The weight savings is nearly 2 lbs. from the stock cast-iron brake disc rotor. Outside diameter of the rotor is 10-1/4″, width is 1/4″, distance between stud holes is 1-3/4″ (on centers), and the overall weight is 4.38 lbs.
The brake caliper may require slight realignment once the thicker stainless steel brake disc rotor is fitted, and bleeding the system is recommended to ensure the absence of any air in the hydraulic brake system. Brake pad replacement is also recommended when the new Girling brake disc rotor is fitted.
The brake disc rotor is retained to the hub with (5) plain nuts and locking washers threaded onto 5/16″ studs. Note: Due to minimal clearance on the stock MK3 front brake caliper, it may be necessary to remove some material from the lower edge of the caliper on MK3 models due to potential interference with the heads of the bobbins, which stand proud by .200″. The bobbins may also contact the inside of the fork leg, which may require shimming the caliper and axle spacer.