Shimano Ice-Tec FREEZA Centre Lock Rotor SM-RT99 180mm. Ice Tech Freeza: The Shimano Saint SM-RT99 disc brake rotor uses the proven Centre-Lock spline fitment system which combines excellent rigidity and security with an easy set-up. This brake disc is designed specifically for use with the Shimano Saint disc brake systems, but provides a worthwhile upgrade for other Shimano brakes where brake fade becomes an issue under aggressive and extended riding. The Ice-Tec hybrid construction bonds two precision cut stainless steel braking surfaces to the outside of an aluminium core which serves to pull heat from the discs surface and dissipate it more effectively to reduce temperatures by around 50°C (100°C when combined with Ice-Tec pads) and prevent brake fade. The RT99 rotor is unique in the Shimano range in that the alloy core extends below the braking surface to create additional cooling fins to provide even more heat radiation than the RT98 rotors. A precision cut and drilled braking surface improves pad clearing in muddy conditions and is super polished for maximum performance, whilst the large 6 arm forged alloy spider supports the rotor itself; significantly increasing rigidity, reducing weight and with the semi-floating design allows for expansion caused by heat to prevent the disc warping. NB: Image for illustration purposes only – supplied as single rotor only.