Brembo behind the first MotoGP triumph with carbon discs in the rain

9/11/2017

 They said it was impossible, but that didn't stop Brembo

​Last Sunday Marc Marquez won the San Marino and Riviera di Rimini GP with carbon discs, despite it raining during the race. A victory that would have been unthinkable just a few years ago and that breaks down the simple pairing of carbon with dry conditions and steel with wet conditions.

The triumph was made possible by the sensational improvements Brembo has made to its carbon discs over the past few years. Thanks to the material used and the increasingly precise production processes, carbon discs have evolved significantly.

Once again, these results confirm that technical innovation is part of Brembo's imprinting. In over 4 decades of motorcycle races, Brembo has successfully overturned several established traditions, introducing technical solutions that seemed impossible to produce or simply inconvenient but that soon became the dominant technology.
           

 
 
 

One need only think back to the monobloc caliper, launched in Formula 1 in 1988 and adapted four years later for the top motorcycle racing event, or to the radial caliper that debuted on the Aprilia 250 in 1997.

And now we're celebrating the triumph of carbon discs in MotoGP. At first glance, things don't seem that exciting, since carbon discs have been used on bikes in the top racing category for decades.

However, as many of you already know, in wet conditions carbon has always had to make way for steel. For one very simple reason: to guarantee a good coefficient of friction , carbon needs to get to temperatures of at least 250 °C, which was quite difficult to do in rainy and wet conditions, until recently.

 

Still, things have been changing gradually over the course of recent years.

On the one hand, more powerful engines and better performing tires have increased the demand placed on brakes even in wet conditions, helping raise the temperatures of brake discs even when racing under the rain.

On the other, Brembo brake discs have been evolving to help expand their operating temperature range.

Combined, these two trends gradually helped bring the performance of carbon discs closer and closer to that of steel discs in wet conditions.

 
 

But the real upset came with the 2015 San Marino GP: the race started in dry conditions, but after a few laps it began to rain heavily. All the MotoGP riders returned to the pit stop to change bikes (opting for brakes configured for wet conditions), all except for Bradley Smith (Yamaha Tech 3).

Despite temperatures dropping, his carbon fiber discs didn't suffer any failure and the Brit was able to take second place. Since then, Brembo has ramped up its testing of carbon fiber discs under the rain, all the while leaving MotoGP riders completely free to choose their brakes. Finally, at the 2016 Malaysia GP, some asked to try the brakes, due to issues with the weather and the intermittent rain.

 


Having taken to the track on Friday with rain tires and steel discs, some riders started to complain about the poor performance. Marc Marquez choose to experiment with Brembo's 320 mm low-end carbon discs (protected by the covers to maintain the temperature) and immediately appreciated the advantages.

Two days later, the race was interrupted by a powerful downpour and, despite the flooded racetrack, the Spanish rider opted for Brembo carbon discs. Brembo technicians analyzed the discs and telemetry at the end of the race and noted the rider's comments that he hadn't had any issues.

 

Actually, getting the most out of carbon brakes requires great skill because the temperature of the brakes is less than optimal during the first laps of the race. To compensate for this temporary issue, the rider must begin using the brakes ahead of time, braking a few meters earlier than usual to raise the temperature.

However, once temperatures are above 250 °C, the coefficient of friction stabilizes. Steel, on the other hand, suffers from high temperatures and can even stretch the brake lever near the end of the race, to the point that it sometimes touches the handlebars.

What's more, carbon doesn't suffer from the friction torque issues that can affect steel brakes in wet conditions. The release phase is faster and guarantees the absence of drag, a feature riders value. In other words, after braking with carbon discs, the tire is immediately free, which makes for better driveability.

 
 

Over the past months, several riders have experimented with carbon discs on water and their views have differed. The victory this past Sunday may have won over even the most skeptical.

Once again, Brembo has seen an opportunity for innovation where others only saw a hazard