XTR SM-RT99 Ice Tech rotors providing consistent braking performance through energy control, using revolutionary stainless steel / alloy 3-layer sandwich construction that manages heat while ridingThe clad steel / alloy / steel rotor construction allows heat generated from braking to radiate quickly through the aluminium core achieving surface temperature drops of around 50 deg C. When used with Ice Tech pads surface temperatures can drop from around 400 to 300 deg C, this provides great improvements in performance all roundFREEZA rotors allow the alloy core to extend out from the braking surface as a fin to providing added coolingIce Tech rotors achieve long pad life, less noise and less fade due to improved heat dispersionRotors are durable lightweight and rigid, using the proven Shimano Centre-Lock system giving increased strength and security with an easy set-upPrecision cut and drilled braking surface improves pad clearing in muddy conditions while aiding cooling under high loadLarge alloy spider is a highly rigid and lightweight support for the rotor surfaceSuper polished braking surface gives excellent braking performanceAverage weight 126 g for 160 mm