Strange noises from the disc brakes is usually due to dirt between the brake disc and the brake pads.

The easiest way to clean the disc brake is with the bike's disc brake cleaning spray.

If you do not have a cleaning spray, you can clean the disc brake with compressed air from, for example, a tire inflator at a petrol station. In addition, the brake disc and saddle should be washed if necessary with a soft brush with a mild detergent solution. You should use detergent intended for bicycle washing as a detergent.

If other noises are heard from the brakes, then the brake pads are worn. Once you have checked that the temperature of the brake system has dropped sufficiently, check that the thickness of both brake pads is at least 0.5 mm depending on the model. The brake disc is worn when its thickness is less than 1.5 depending on the model, or the aluminum surface has been exposed.

Do not allow oil or grease to enter the brake discs or brake pads. Otherwise, the brakes may not work properly.