How to Silence Squeaky Disc Brakes on Your Mountain Bike
To stop squeaky disc brakes on a mountain bike, first clean the rotors and brake pads with isopropyl alcohol. Then, bed the brakes by braking hard several times in a row and avoid dragging the brakes. Adjust the brake pads so they are not hitting the rotors unevenly or too tightly. Finally, try a different brand or compound of brake pads if the squeaking persists.