CenterLine 2-piece rotors are the lighter-weight version of SRAM�s quiet, smooth and robust CenterLine rotors CenterLine venting reduces vibrations by providing consistent friction levels throughout the rotation 2-piece design offers reduced weight as well as improved heat shedding abilities Rounded edges make for easier wheel installs and are UCI-compliant. Available in 6 Bolt and CenterLock configurations Aluminum body with steel braking surface 6 Bolt models feature titanium mounting bolts 180mm Black Centerline 6B