Reynolds Cryo Blue Carbon Rim Brake Pads Shimano. If you're planning on riding some shiny new carbon rims, you're going to need carbon fiber specific brake pads. Carbon rims are lighter, stiffer and usually more aerodynamic than their alloy counterparts, but they also don't shed heat as efficiently and historically have had poorer braking performance. But Reynolds found a way around that with their new Cryo Blue brake pads. They're specially formulated to work with Reynolds rims to prevent excess heat buildup and dramatically improve braking performance. The unique properties of these pads also virtually eliminate squealing, which can be a problem on carbon rims even with properly toed brake shoes. These come as a set of 4 and are designed for Shimano brakes.