It's raining! Now everyone uses Brembo carbon discs. This is what's changed

10/31/2017

In the past, carbon was outlawed in the rain as it was inefficient, but in Japan it was used by the first 9 riders to cross the line, with excellent results.

"There is no challenge More challenging Than the challenge To improve yourself"
(Michael F. Staley) "

"No-one, one and one hundred thousand. ."

We paraphrase the title of the famous book by Luigi Pirandello to explain the momentous turning point that MotoGP is experiencing. The Japanese GP took place on Sunday 15 October 2017: Andrea Dovizioso crossed the line first in the MotoGP race, 0.249 of a second ahead of Marc Marquez and 10’’557 seconds in front of Danilo Petrucci.

Behind them were Andrea Iannone, Alex Rins, Jorge Lorenzo, Aleix Espargaro, Johann Zarco and Maverick Viñales. A spectacular race with continual changes at the front despite the rain never letting up for the entire 24 laps. Yes, because from lights-out to the checkered flag, a period of more than 47 minutes, it never stopped raining. More significantly, the air temperature never exceeded 14°C nor the asphalt 15°C.

Tough conditions that, in the past, would have seen all riders using the same braking solution - steel discs. Yet all three riders on the podium used Brembo carbon discs, as did the six who followed them across the line.

A total of 13 out of the 15 riders who scored points used Brembo carbon discs in fact. Essentially, at least one bike per manufacturer completed the race inside the first 15 positions using carbon discs: 3 Ducatis, 3 Yamahas, 2 Hondas, 2 Suzukis, 2 Aprilias and 1 KTM.

A very significant result that proves the validity of Brembo carbon discs in the rain, regardless of the individual characteristics of each bike.

Thanks to carbon, riders at the Twin Ring Motegi were able to enjoy a bike dynamic that was not too different to what they would have had in the dry.

Steel, in fact, has a negative effect on a bike's dynamic behavior because it is a heavier material than carbon. The reduction in unsprung mass ensured by the Brembo carbon discs influences suspension behavior because the wheels stick to the asphalt better. This translates into better rideability and the possibility to transfer greater power to the ground.

In other words, even in the rain, carbon guarantees better performance when it comes to both acceleration and changing direction. Improvements that may seem infinitesimal but that, when put to the test, translate into a quicker lap time. Yet, despite the drenched track, Dovizioso was able to complete a lap in 1’56’’568, taking 11’’218 longer than the best lap record at this track, or rather 10.6% longer. T

hat might sound like a lot but, by drawing a parallel, you'll see that the opposite is true. At the 2016 Dutch GP, which took place on a wet track but with rain that was stopping, Danilo Petrucci set the best lap time, a 1’48’’339. 14’’722 higher than the Circuit Record Lap, equal to 15.7% longer. Petrucci, like his colleagues, used steel discs on that day.

10.6% longer in one case, 15.7% longer in the other. No words are needed, though out of intellectual honesty we should point out that the difference between carbon and steel is not always so marked. There's no denying though that carbon discs perform better, once they are up to their minimum working temperature.

To ensure a good friction coefficient, carbon must reach at least 250°C, practically unthinkable, until recently, in the case of race or a fully wet track. Over the course of recent years though, an increase in bike power, tire development and the evolution of carbon have led to a new scenario: on the one hand, increasing the effort required by MotoGP bike brakes in the wet, on the other hand, allowing brakes to reach the necessary temperature range more quickly.

Initial proof of the fact that carbon brakes had essentially caught up with steel brakes in the rain came at the 2015 San Marino GP. On that day, as it started to rain, all the MotoGP riders came into the pits to change bike.

Leaving their dry bikes, with slick tires, they climbed on to the bike configured for the wet, so with steel discs. The only rider who didn't come into the pits was Bradley Smith (Yamaha Tech 3) but despite a drop in air temperature, his carbon discs did not suffer and he was able to cross the line in second position.

From then on, Brembo intensified its testing of carbon in the rain, although MotoGP riders were free to make their own choice as to usage. Up until the 2016 Malaysian GP when, on the Friday, several riders asked to test them owing to the poor performance of the steel discs.

Among these riders was Marc Marquez who, having noted the benefits of the Brembo 320mm low strip carbon discs over the course of the weekend, wanted to use them in the race too, despite a soaking track, drenched following a violent rain shower just moments before.

On that day, the Spaniard lost the front of his bike, crashing into the gravel, but he had set the fastest lap of the race just moments before. Marquez climbed back on and finished in 11th place.
Furthermore, after the race, Brembo technicians analyzed the discs and telemetry and listened to the rider's comments, confirming that there were no problems.

On 10 September, the very same Marquez won the 2017 San Marino GP with Brembo carbon discs despite rainfall during the race. He was joined on the podium that day by Petrucci and Dovizioso, though on that occasion the two Ducati riders opted for Brembo steel discs.

One month later, the situation was turned on its head, when three days of rain at the Japanese GP meant that even the most skeptical of riders had chance to test the goodness of Brembo carbon discs. A result that wasn't exactly taken for granted, considering how each rider requires a personalized set-up of the braking system, one that guarantees him the right feeling.

Supported on track by Brembo technicians who explained the correct way to use carbon discs in the wet, the riders experienced significant benefits, with 19 of them opting to use them in the wet. Lap by lap, and having found the limit, riders were able to improve their performance with all of them confirming their satisfaction after the race.

Essentially, in little more than a month, the results for Brembo carbon discs in MotoGP in the rain had gone from zero to 2 victories.

But, more to the point, this solution, considered unusable until just a short time ago, is now becoming the standard in the reigning class. Furthermore, the revolution seen in MotoGP in October took place in much more critical conditions to those seen during the race at the Misano World Circuit Marco Simoncelli because, on that occasion, it stopped raining during the second part of the race.

To function perfectly, carbon requires great expertise because in the early stages of the race, its temperature is less than ideal. 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 in high temperatures and, towards the end of the race, there is a risk inconstancy of the brake lever. What's more, carbon doesn't suffer from the friction torque issues that can affect steel brakes in wet conditions.

With carbon discs, the release phase is more rapid and guarantees that absence of drag sought by riders. In other words, after braking with carbon discs, the tire is immediately free, which makes for better rideability.

Those 115 km completed by 19 riders, including the first 9 to cross the line, represent a little step for MotoGP and a big step for the history of motorcycling. But this is not to say that Brembo won't continue to focus on carbon development.

We aim to take further steps forward, in terms of the materials and construction techniques used, in years to come, with the hope of being able to transfer carbon discs to as many road-going bikes as possible.

ecause even if we supply our braking systems to 100% of MotoGP riders, we continue to seek new challenges.

Only by doing so can we continue to improve.