A squealing bike brake is usually caused by dirt, oil, or moisture on the brake pads or rims. If ignored, it can reduce braking efficiency and damage the pads. Clean the brake surface with a degreaser and ensure the pads are properly aligned. Also, check if your bike chain is clean and well-lubricated, as excessive vibration from a dry chain can amplify noise. Regular maintenance and timely cleaning prevent such issues. Get expert on-site repair through Crossroads Helpline.