What does the SRAM 20mm Flat Mount Disc Brake Adaptor do?

The SRAM 20mm Flat Mount Disc Brake Adaptor allows a flat mount disc brake caliper to be used on a frame or fork that positions the flat mount caliper interface 20mm lower than standard — the adaptor bridges that offset to bring the caliper into correct alignment with a 160mm rear rotor. Flat mount is the dominant disc brake standard on modern road and gravel frames, but not all frames position the caliper mount at the same height relative to the rotor centerline. Without the correct adaptor, the caliper cannot be aligned properly over the rotor, which causes uneven pad contact, inconsistent braking, and the inability to center the caliper regardless of how the mounting bolts are adjusted. Includes stainless steel mounting bolts.

This adaptor is specific to rear 160mm rotor use. Verify both the rotor diameter and whether your frame requires a 20mm offset flat mount adaptor before ordering — frame and fork specifications will indicate whether an adaptor is required and what offset is needed. Compatible with SRAM flat mount hydraulic disc calipers across the eTap AXS road brake lineup including RED, Force, and Rival, as well as any flat mount caliper using the standard flat mount bolt pattern. If your build uses a 140mm rotor or a different offset, verify the correct adaptor spec for your configuration. Install with a torque wrench to the caliper manufacturer's specified torque value.