At Shimano they always do stuff like adding drastically improved heat management to their next generation of disc brake rotors and still make them lighter as well. Sound crazy? Well, maybe so...but the new XTR disc brake Freeza rotors use the IceTech aluminum core clad in stainless steel, but take it a step further with the aluminum core flowing out into the center of the rotor in the form of Freeza cooling fins, a system that further discourages heat radiation. This means an incredible 150° of cooling with the RT99 rotor compared to a standard steel rotor...and throw in some finned brake pads; they can further reduce heat build up by 50°. The bottom line is modulation unaffected by heat, eliminated brake fade, and fingers that can last all the way down the mountain.
Item No. » SH-RT99