Scrub wheels and tires using a stiff bristle brush, and a proprietary wheel-cleaning product if necessary, to remove dirt, grease and disc-brake powder.

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"We must have hit a rock because it smashed the wheel and we had to drive the final seven kilometres with the car running onto the brake disc, " said 30-year-old McRae.

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And that smooth drag comes from the graphite-impregnated cork disc, which acts like a brake pad, slowing it down without locking.

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Stanley invented a double-brake system using two brake shoes supported by springs that clamp down on a disc.

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