The purpose of a brake rotor is to slow down or completely stop a wheel while it is in motion. Friction is applied in the shape of brake pads on both sides of the brake rotor to stop the wheel. This friction causes the brake rotor to slow down or stop and ultimately this action is transferred onto the wheel.

 

As the Laws of Physics explain, friction causes motion to transform into heat. But, if the brake rotor is incapable of dissipating the excess heat accumulated, it becomes too hot and consequently less effective. This phenomenon is known as brake fade.

 

In addition, friction causes, depending on the materials the brake pad and rotor are made of, gas build up between these two surfaces. The gas build up also limits the stopping power of brakes. Another issue in brake rotor efficiency is the collection of water between brake rotors and pads. Since friction is proportionate to the surface tension, a wet surface severely reduces brake efficiency. Finally, the accumulation of dust particles in between the brake components not only limits the stopping effect they also wear out a rotor.

 

Cross drilled brake rotors, first used on racing cars in the 1960’s, solve these issues of inefficiency. Drilling holes in cross drilled brake rotors makes it relatively easy for heat, gas, water and dust particles to be swept away, resulting in a better brake performance and durability of the rotor.

 

The material from which the brake rotor is made up of is also a deciding factor in heat dissipation and durability. Modern day cross drilled brake rotors are made of reinforced carbon-carbon or ceramic matrix compounds.

 

Cross drilled brake rotors are mostly used in high performance automobiles. A combination of cross drilling and slotting on brake rotors are preferred for use in race circuits, since they maintain brake pad softness and evade melting, transformation of solid to liquid (and vice versa), of their surfaces.

 

Regular maintenance of cross drilled rotors is essential. Spraying water at high pressure for a small period will be sufficient to remove all dust particles from the holes of the cross drilled brake rotor.

 

It is unwise to drill holes on solid brake rotors. Since, cross drilled brake rotor designs are repeatedly examined for stress crack sites that could cause brake rotors to come apart under stressful use. To take a solid rotor and drilling holes on it is an accident waiting to happen.

 

The negative aspects of cross drilled brake rotors are mainly its high price. Additionally, users have reported that cross drilled brake rotors improve braking in competitive situations, and offer an insignificant advantage in normal street conditions. Finally cross drilled brake rotors wear out the brake pads swiftly.