Wilwood’s C/SiC Rotor and Bobbin Driven Hat Assemblies are preassembled packages of our latest and greatest technology and design. The bobbin drive rotor mounting system eliminates typical fixed mount schemes and instead, a spring loaded bobbin assembly retains the rotor in the hat. This system allows the rotors to move independently of the hats as they expand and contract through heat cycles. All thermally generated stress is removed from the rotor attachment points. The rotors stay flatter and run truer. Paired with C/SiC rotors that are made form a proprietary blend ceramic matrix composite material commonly known as Carbon-Ceramic. C/SiC rotors offer higher thermal conductivity and heat capacity in excess of conventional iron or titanium rotors of similar or even greater weight and are developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear.