How do I know when to replace my rotors? August 31, 2016 13:37 If the rotor’s brake track measures less than 1.55mm thick it needs to be replaced. Related articles Why did SRAM choose DOT 5.1 over mineral oil? What size disc brake rotors does SRAM recommend for eTap AXS HRD? How do I know when to replace my eTap® HRD 2x11 brake pads? What tubeless tires are compatible with Zipp’s hookless rims? Why are my SRAM eTap AXS disc brakes noisy? Comments 0 comments Article is closed for comments.