Why do my SRAM road disc brake pads rub? Over time, dirt and grime can keep caliper pistons from moving freely and even cause excessive brake noise. To help you achieve the best brake performance, we created this eTap AXS Disc Brake Troubleshooting guide. Related articles Why are my SRAM HS2 Rotors rubbing against the pads? What are SRAM eTap AXS enhanced shift modes, and how do I enable them? What is the difference between flat mount and post mount calipers? How do I size a chain for a SRAM eTap AXS 2x drivetrain? What variations of SRAM CenterLine XR rotors are available?