The brake dilemma Bagnaia faces at MotoGP’s Italian GP

The hot topic at Mugello for this weekend’s Italian Grand Prix is brakes. With Francesco Bagnaia’s much-publicised change in brake disc specification on Sunday in Aragon, there has been plenty of discussion about the improvement in feeling that comes with selecting a larger disc size.

However, increasing the diameter of a rider’s brake discs isn’t a silver bullet that unlocks performance, and brings with it other drawbacks to consider – such as added weight. 

Brembo’s Andrea Pellegrini outlined what happened at the Motorland circuit and how Mugello presents a different challenge in terms of braking performance.

“Basically, Pecco started [at Aragon] with his standard configuration: the 340mm high mass disc,” said Pellegrini. “Because the category of energy at Aragon is high so, for this reason he started with the standard solution and, during the warm-up, he moved to a 355mm. 

“This track [Mugello] is light in terms of energy on the brakes compared to Aragon, but he is using a 340mm standard mass now and if he moves to a 355mm it puts a lot of weight not only the weight of the different disc, but you also have to put some sort of cover in order to warm up the temperature immediately.” 

When quizzed on the key performance parameters to look out for, Pellegrini discussed how sensitive temperature control is on the MotoGP bikes and how the disc changes the handling of the bike as well. 

“You need to control the temperature,” said Pellegrini. “If you are very low with the temperature you don’t have the stopping power you need so you have to warm up the disc.  

“To warm up the 355mm disc, you have to put extra covers which puts extra weight on the bike. Also, the handling of the bike is different with more weight on the front axle.” 

An interesting detail that Pellegrini revealed was that there will be small differences in specification between the two riders in the factory Ducati garage. 

“Here in Mugello, he [Bagnaia] starts with the 340mm standard mass disc, and his team-mate Marc Marquez stays with the 340mm high mass because the management of the temperature is different between the two discs.”