Hope RX Disc Rotor - 140mm, Center-Lock, SilverThe Hope RX Floating Centre Lock disc brake rotor is a high performance disc, allowing the stainless steel outer to expand separately from the aluminum centre and handle high temperatures without warping. 2 piece floating design allows the laser cut 410 stainless steel outer to expand separately from the CNC machined center to handle high temperatures without warping True floating design allows 1 degree of freedom so outer is always free to expand