For superb stopping power in all conditions, SHIMANO ULTEGRA SM-RT800 disc brake rotors deliver consistent braking performance thanks to the ICE TECHNOLOGIES FREEZA construction. With better heat management, the SM-RT800 rotors withstand brake fade on long downhill stretches and provide substantially quieter braking. SHIMANO's CENTER LOCK mounting system makes installing and removing rotors quick and easy with the spine mount and lock ring design.