In order for a disc brake to work to its optimum potential, the disc mount on the frame should be exactly parallel to the disc itself. Usually most frames are constructed and finished well enough that the caliper can be adjusted to align well with the disc. However, some brakes have little adjustment, and some disc mounts may not be perfectly parallel with the disc. If this is the case, then facing the disc mount may be required.

This is done using a specialist tool, usually in a bike shop. Hope's disc mount facing tool is designed to perfectly machine the face of each tab, removing paint and material to create a flat surface.