XTR SM-RT98 Ice-Tech rotors providing consistent braking performance through energy control using revolutionary stainless steel / alloy 3-layer sandwich construction that manages heat while riding The 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 round Ice-Tech rotors achieve long pad life less noise & less fade due to enhanced heat dispersion Rotors are durable lightweight & rigid using the proven Shimano Centre-Lock system giving increased strength & security with an easy set-up Precision cut & drilled braking surface improves pad clearing in muddy conditions while aiding cooling under high load Large alloy spider is a highly rigid & lightweight support for the rotor surface Super polished braking surface gives excellent braking performance Average weight 126 g for 160 mm