In a previous press release, Brembo explained why the MotoGP bikes shifted to 340mm carbon discs. Now, the manufacturer delves deeper into the use of carbon brake discs and the importance of maintaining proper operating temperature. As with the prior installment, the interview below is with Lorenzo Bortolozzo, Brembo MotoGP Customer Manager.
Begin Press Release:
How do they exploit the operating temperatures of carbon brakes?
When going from 320 mm discs to 340 mm ones, who has had the adapt most? Late brakers?
“Actually no because there are riders who brake using a lot of initial pressure like Cal Crutchlow and then release the brake almost immediately, whereas there are others who use a lot of pressure initially and then modulate it like Andrea Dovizioso, Valentino Rossi and Marc Marquez.
“There are also riders who use less severe braking like Daniel Pedrosa and Jorge Lorenzo. The two Spaniards do not brake hard but go very fast on the bends. There are different ways of controlling braking which makes it difficult to say if one brakes better than the other.
“In fact, every rider has a different way of braking from the others: some keep their hands on the lever more and some less, some use the brake a lot initially and then release it, and some use it gently at the start and them modulate braking until they release the lever.”
Does the Brembo system “prefer” any of the three types of braking you have described?
“No, because the coefficient of friction for carbon is excellent from 200 to 800 degrees and so it is just a question of a rider’s style. It should be added that when developing the system, we had a lot of help from the teams who worked hard to improve cooling of the discs. The shape of the fenders has been modified so that more air is directed onto the discs.”
Once you reached the safety threshold, did you also work on improving performance?
“Of course! With a 340 mm disc, MotoGP riders have an extra supply of braking torque that can be used when braking or when in difficulty. It should be added that with the large disc, it was more difficult to modulate braking even if the riders were quick to adapt…”
What has changed?
“With the 340 mm disc there is more initial bite than with the 320 mm disc. Obviously, this is not a problem but then after the initial bite, the riders tend to modulate braking even on the bend. This means that they begin the turn with the brake lever pulled and then gradually release it until they start accelerating again.”
What are the consequences of doing this?
“During modulation, which is no longer maximum braking but control, the riders are more aggressive with the discs and this may cause a low side, something which has happened at times. The riders have therefore had to adapt their style of riding and their sensitivity when braking to the characteristics of the 340 mm brakes.”
So far we have talked about cooling brakes, but are there any circuits where devices are used to heat the discs? The exact opposite…
“Yes, this happens on Phillip Island, for example, where racing is held in the winter and temperatures are very low. Therefore, in Australia, the teams use carbon covers to “clothe” the discs and keep minimum temperatures for use at over 200 degrees. The same problem usually occurs at Assen or Le Mans when the climatic conditions are not ideal. It should be stressed that we also have two different specifications for the two disc diameters: “high braking surface” ones with full mass and “low braking surface” ones with a smaller surface area to facilitate heating. We introduced the carbon 340 mm disc with a low braking surface only recently: the riders appreciated this because they couldn’t use the large discs on some tracks since they were not able to get them to the right temperature if it was cold. In this way, we have managed to cater for all requirements, even in critical situations.”
If the all-important 200 degrees are not reached, are there safety issues?
“No, the system works all the same, but there are significant differences in performance.”