Sram centreline x road 2 piece ss disc rotorcreated by sram to get the best possible performance from your road bikes sram disc brakes, the centreline x road model is lightweight and runs smoothly and quietly. Featuring rounded edges to make it uci compliant and an alloy central section to draw heat away from the stainless steel braking surface, youll enjoy fade free braking power on long descents. The rounded edges also help to speed up wheel changes should you encounter a puncture on your ride.features bolt material braking surface stainless steel central floating section alloy mount type standard 6 bolt brake compatibility compatible with both road and mountain bike sram brakes rotor type 2 piece lightweight, two piece design rounded edges are uci compliant and allow for easier wheel installs sold individually includes steel rotor mounting bolts manufacturer's part number rt cln x a2 weight 140mm 128g 160mm 154gbuy sram components from chain reaction cycles, the world's largest online bike store.