Shimano XT RT86 Ice Tec 6 Bolt Disc Rotors for 2012 have a clad steel and alloy construction that allows heat generated from braking to radiate quickly through the aluminum core achieving surface temperature drops of around 50 deg C. When used with Ice Tec brake pads surface temperatures can drop from around 400 to 300 deg C, this provides great improvements in performance all round. As for example mens mountain bikes that continue to become more diverse, bike components must evolve. Deore XT addresses the needs of today's riders just like it did when it was first introduced back in 1982 as the world's first MTB group. Revolutionary new designs like the Shimano XT RT86 Ice Tec 6 Bolt Disc Rotors complement the the latest evolution of traditional designs to give you the right choice for your riding style These RT86 Ice Tec bike disc rotors from Shimano give excellent performance with a rotor surface that hes been developed for excellent pad clearing and cooling. This innovation increase the life and performance of the brake pad. In addition, the Shimano XT 6 bolt disc bike rotor benefits from a large forged alloy spider that supports the rotor surface. This increases the rigidity of the disc rotor and reduces the weight. Shimano XT RT86 Ice Tec 6-Bolt Disc Rotor Features Large forged alloy spider supports rotor surface, increasing rigidity and reducing weight Ice-Tec rotors achieve long pad life, less noise and less fade due to improved heat dispersion 6-bolt mounting system Rotor contact surface has been developed for excellent pad clearing and cooling which increases pad performance and life