Formula 1 cars are all fitted with brake discs and pads made of a composite material called carbon-carbon, capable of truly astounding performances and endurance.

Lighter than steel and capable of withstanding distinctly higher temperatures, the carbon/carbon composite with which an F1 car’s brakes are manufactured was discovered in 1958 following the accidental pyrolysis of a fibrous composite.

Carbon braking system offers very high levels of friction, which translates on very powerful braking and short braking distances. Carbon brakes first appeared in Formula 1 in the early 80s on the Ligier-Matra and Brabham cars, but only during testing.

The discs are glowing red under hard braking. Photo: WRI2

After thousands of kilometres of testing and development with French firm Carbon Industrie, Niki Lauda and Alain Prost’s McLaren-TAGs clinched a one-two sweep in the 1984 World Championship. Since then all teams have adopted these brakes and a few other companies have also taken the plunge, supplying carbon discs and pads for F1 teams.

Manufacturing carbon brake components is a lengthy process. “You start with a fibrous white carbon fabric that looks a little like Santa’s beard,” explains Philippe Rerat, business manager of Carbone Industrie, a subsidiary of Messier-Bugatti established in Villeurbanne, a suburb of Lyon, France.

“This nearly isotropic fabric is called Novoltex. The fabric is first carbonized in a special furnace. It is then cut in the rudimentary shape of the part to be produced, whether it’s a brake disc or a pad,” Rerat said to Auto123.com.

Carbon-carbon disc brake of a Formula 1 car. Photo: Matthieu Lambert Auto123.com

“The next step is called the densification of the material, which is done in a chemical vapour infiltration furnace. By using a hydrocarbon cracking process at 1,000 degrees C, pyrolitic carbon is perfectly mixed into the Novoltex. The material densifies, meaning it becomes more compact, as the cavities inside it fill up.”

“This is a very long process that takes weeks. Finally, The parts are carefully machined according to precise specifications. It takes over five months to manufacture a set of brakes. It used to take nearly six months, but we managed to reduce the intercycle time.”

Carbon fibre brake components are five times lighter than identical steel components. What’s more, carbon fibre discs are impervious to thermal shocks, have mechanical characteristics that improve when heated -- the complete opposite of traditional steel -- and can withstand extremely high temperatures, up to 1,000 degrees.

The discs wear out slowly and resist oxidation up to 500 degrees. The very high friction coefficient of carbon fibre enables an F1 car to decelerate from 320 to 100 km/h in 120 metres or three seconds. The friction coefficient varies little, even at extremely high temperatures.

And contrary to urban legend, carbon fibre brakes perform quite well even when cold.





Photo Credit : Matthieu Lambert - Auto123.com