Brake rotors, used for heat dissipation in vehicles, are the round steel parts located behind a car's wheels. When the brakes are applied, the brake pads and calipers clamp the rotors to slow the vehicle and aid in cooling the brakes. Brake rotors have several designs to suit different cars' needs. Some cars require the brakes to cool down as quickly as possible, so brake rotors can be modified for this purpose.
Cross-drilled Rotors
The holes drilled through the cross-drilled rotor spread out over the entire surface of the rotor to help it cool down during breaking. The holes allow air currents to move through the rotor to facilitate breaking and heat dissipation. Because they are very efficient during aggressive breaking, many performance and race cars come with cross-drilled rotors. Although it is a common upgrade for street cars, poor quality cross-drilled rotors can crack prematurely if the drilling is not done properly. In a race car, this is not a problem because brakes are changed after every race; however, this can lead to permanent damage and safety hazards in street cars.
Grooved Rotors
Grooved rotors get their name from the vents inside the rotor, which are only visible when looking at the edge of the rotor. Like cross-drilled rotors, the vents help to keep the rotors at a cool temperature during breaking.
Dual-ventilated Rotors
Dual-ventilated rotors are much like grooved and cross-drilled rotors, but instead of one rotor, they typically come with two. The vanes between the two rotors generate an air vortex which aids in cooling the rotors. They are much more efficient than other types of rotors when it comes to heat dissipation.
Composite Rotors
Composite rotors are a combination of different rotor features, such as cross-drilled and grooved for maximum cooling ability. They are often found on performance and race vehicles such as high-end Ferraris and most F1 race cars due to their superior heat transferring abilities.
Standard Rotors
The most common type of brake rotor is the standard rotor used on street or production cars. They are made of cast iron in a variety of thickness and diameters. Each rotor has a minimum thickness and must be measured to ensure it does not go below the legal minimum, which means the rotor will not be capable of handling the high heat generated by the brakes.
