Excellent braking performance thanks to their stainless steel & alloy 3 layer design, the Shimano XT RT81 Disc Brakes manage heat while riding to ensure you dont suffer from brake fade, even on the longest descents. With the unique alloy sandwich, the outer surface of the disc brakes are reduced by around 50°C & when used in combination with Ice-Tec pads, the SM-RT91 Rotors are even cooler for the ultimate performance. The added advantage of reduced heat is increased life, less noise & minimal fade. A proven Shimano Centre-Lock mounting system offers superb rigidity & security combined with an easy set-up while the large forged spider supports the rotor surface for increased power & minimal weight.