The Shimano SM-RT99 XTR/SAINT Freeza Centerlock rotor is the pinnacle of Shimano's ICE Technology development. First featured in Pro Downhill mountain bike racing, the line has been expanded to include all sizes of rotors so other disciplines can too can enjoy the benefits of this top-of-the-line brake technology. The RT99 features Ice-Tech technology which is Shimano’s best-in-category heat management system. Brake heat from long descents sucks power from your brakes, but not with this rotor. The heavily shaped, lightweight Freeza rotor sheds heat incredibly fast for optimal performance, even in the most demanding conditions. A cooler rotor means more braking power, and more consistent braking performance, so you can forget about your brakes and focus on your riding.
The RT99 rotor with its additional cooling fins radiates significantly more heat than the already remarkable RT98. The benefit to you? when used in conjunction with other Ice-Tech technologies such as Shimano's finned disc brake pads and mineral oil brake systems, you can even go down one full rotor size to save weight without any decrease in cooling performance!