Rotor Meaning in Cycling

A rotor is the circular metal disc attached to the center of a bicycle wheel in a disc brake system. When you pull the brake lever, the brake pads squeeze this spinning disc to slow you down. Rotors are usually made of stainless steel and feature many small holes to help dissipate heat. This heat management is essential to prevent the brakes from fading during long, steep descents. They come in different sizes, with larger rotors providing more stopping power for heavy bikes or fast riding. You must keep the rotor clean and free of oil or grease to ensure the brakes work correctly. For example, a downhill mountain biker uses large 203mm rotors to stay in control while flying down a mountain. If a rotor gets bumped, it can warp and rub against the pads, making a rhythmic scraping sound. Most modern bikes now use this system because it works better in the rain than old rim brakes.