GFB's lightweight underdrive crank pulley is made from anodized aircraft-grade billet 6061-T6 aluminium and offers sharper throttle response and faster acceleration.

GFB pulleys are designed to improve acceleration by reducing the rotational mass (inertia) on the crankshaft as well as parasitic loads from the driven accessories. The effect is similar to a lighter flywheel, and the engine feels more lively and willing to rev.

The underdrive ratios have been optimised to ensure there are NO adverse effects on the performance of the accessories, and whilst it is true that some engine types do suffer harmonic issues from lightweight pulleys, the kits GFB release are thoroughly application tested and do NOT cause engine damage in the short or long term.

GFB products are manufactured in Australia and the company is accredited to ISO 9001, which ensures products meet stringent quality requirements at all stages of manufacture.