The shimano saint sm rt99 ice tech freeza centre lock rotor produces consistently high quality braking performances thanks to its new 3 layer build design ensuring that the shimano rotor keeps cool at all riding intensities the 3 layer rotor build is a sandwich style made from steel alloy steel this creates an unbeatable cooling system as the heat generated from the braking system is radiated much more quickly through the aluminium core than standard rotor systems the ice tech