Disk Caliper

The brake caliper is the assembly which houses the brake pads and pistons. The pistons are usually made of plastic, aluminium or chrome-plated steel. Calipers are of two types, floating or fixed. A fixed caliper does not move relative to the disc and is thus less tolerant of disc imperfections. It uses one or more pairs of opposing pistons to clamp from each side of the disc, and is more complex and expensive than a floating caliper.