A Motorcycle Brake System with C/C-SiC Composite Brake Discs

There has been a lot of interest recently in brake discs produced from carbon/carbon-siliconcarbide (C/C-SiC) composites for automotive and motorcycle brake applications. This composite material consists of a 2D C/C composite core and a hard SiC surface layer. The latter is produced by an in-situ reaction that takes place during a liquid-silicon-infiltration (LSI) process in a high-temperature furnace under vacuum. This composite material has excellent physical and chemical properties, including a low density (1.75 g/cm3), an extremely low wear rate and a high resistance to thermal and mechanical shocks. In order to take advantage of this material for brake discs, a novel brake system has been developed consisting of a “floating” fixture for the C/C-SiC brake disc on the hub, a specially redesigned brake calliper equipped with zirconia-toughened mullite pistons that have a low thermal conductivity, and sinter-metallic brake pads. The new brake system is lighter than any conventional metallic system, it exhibits superior friction characteristics (high coefficient of friction and low wear), and it has excellent braking performance. The system is also safe and has been approved by TüV, Garching, Germany.