Rear Disc Diameter: 260mm X 8mm Rear Disc Thickness: 6.5mm Rear Disc Type: Solid | Coated Rear Disc Style: Dimpled and Grooved Dimpled Grooved: The key benefits of the dimpled and grooved discs are that brake fade is significantly reduced. the science behind this is the dimples and the grooves deglaze the pad and vents gasses that build up between disc and pad during braking. The additional slots dissipate heat more effectively, thus greatly reducing the risk of deformation, vibration or cracking of the disc at extreme operating temperatures. Silver Coating: All Kinetix sports discs are Coated Silver to prevent the discs from corrosion in areas not swept by the brake pad. Optimum brake performance is realised after the zinc coating has been removed from the pad track area, which can.