https://www.jumpochina.com/how-often-should-the-brake-discs-of-a-motorcycle-be-replaced.html In simple terms, a motorcycle brake disc is a round disc that rotates when the motorcycle is running. The brake caliper clamps the brake disc to generate braking force. When holding the brake, the brake pad clamps the brake disc to slow down or stop. Disc brakes work well, but they are also more prone to wear than drum brakes.