What is a motorcycle brake disc The brake disc, in short, is a round plate that rotates when the motorcycle moves. The brake caliper clamps the brake disc to generate braking force. When holding the brake, the brake block clamps the brake disc to decelerate or stop. The braking effect of the brake disc is good, but it is also easier to wear than the drum brake. The motorcycle brake disc and motorcycle brake pads and other brake accessories need to be replaced regularly. Replacement mileage of brake disc Generally speaking, the brake pads (that is, the two brake calipers) need to be replaced at about 20000 or 30000 km, while the replacement mileage of brake discs is generally about 40000 or 50000 km. Of course, the replacement mileage is not absolute. It is determined by the driver's driving habits (whether he likes sudden braking), road conditions, maintenance intervals and other factors.