You may have noticed that we did not distribute the Michelin press release following the Grand Prix in Aragon, contrary to our usual practice.
In fact, you will make up your own mind. reading it here, but we thought that, for once, he omitted some of the problems encountered in the race, whether by Dani Pedrosa with his front tire, photos of which were distributed on the Internet, or even by the Ducati, none of whom finished in the Top 10.
We therefore wanted to question Nicolas Goubert (Deputy Director, Technical Director and MotoGP Program Supervisor, Michelin Motorsport) on the subject in order to obtain some answers. This is done, thanks to his great availability and we thank him for it.
In Aragon, we saw Andrea Dovizioso perform very well in the warm-up and at the start of the race, before he slowed down to finish, certainly first Ducati, but 11th, more than 30 seconds behind. What happened?
“Dovizioso basically had a vibration problem on the rear tire. There was indeed some rotation on the rim, which could have caused vibrations, which could be detrimental. So in what turn this happened, I don't know because we haven't yet contacted the Ducati people who have to see it at the acquisition. This is what caused the weakening of Dovizioso's times. If the assembly is assembled and well balanced at the start of the race, this unbalances the assembly afterwards. This appears when we move from torque and there can be several causes; this is of course an unsuitability of the tire on the wheel despite its non-slip coating. These are all more or less equivalent to the eye, but only more or less because in fact they are not at all, and if you run your finger over you will see that they are not equivalent at all. It's not something very easy to adjust because if you put too much anti-slip, it prevents the tire from sitting correctly on the rim and it also causes vibrations, but that's from the start. So this is something that we really didn't need to work on with Ducati, but we have to look at why this happened, because there could also be wear on this coating. We haven't had this problem since the start of the season and it's only appearing now, so we have to look.
The other very important point is that, from time to time, Ducati chooses softer rear tires than others. Often when this happens they are not the only ones and sometimes Pedrosa, sometimes Lorenzo, also make this choice. But in this race, in Aragon, the leading riders had the hard rear tire, while the Ducati had the Soft. In addition to the vibrations, whether this played a role in Dovizioso’s loss of performance would not be a big surprise…”
It is true that with the number of solutions usable today in racing, greater than in the past, it is up to the driver and his team to choose the right one, and this sometimes comes down to the starting grid...
“Yes, the ball is in their court and this choice is not easy, otherwise no one would ever be wrong (laughs). It turns out that, until now, the daring choices have rather paid off, especially since, often, it was not on all eight motorcycles. But here, I think it was a little more daring, and it didn’t pay off.”
Two photos of Pedrosa's front tire have been circulating on the Internet. What happened?
“Yes, I would say that it is regrettable because it is obvious that this is not a normal aspect of the tire, we are not going to hide it. The most important thing is that he was able to finish the race safely despite strong vibrations. In what position he could have finished without damage, I don't know. I don't think he would have threatened the top three but he certainly would have finished in a better position. “It’s safe and it’s unfortunate, and we’re analyzing the tire to find out what happened.”
Can we therefore think more of an isolated tire defect rather than the result of a combination of choice of rubber/settings/rider characteristics/riding style, since Pedrosa had the same equipment as the official Yamahas?
“He had the same tires as Lorenzo, not Valentino…”
On the table you posted, the two Movistar Yamaha riders had the same tires...
“We must pay attention to this table because it is restrictive and only indicative. Pedrosa didn’t have the same (front) tire as Valentino and had the same one as Lorenzo and quite a few Ducati riders.”
Meaning Rossi had a hard tire on the front?
"No. It's a bit complicated to go into detail. The first three drivers had three different (front) tires. The Pedrosa/Lorenzo/Dovizioso tire was the softest of the three. Dovizioso complained about it, but he complained about it on the right side, which was not very demanding, and I think he was mainly bothered by the vibrations caused by the rear. This is my conclusion because it is impossible for the driver who has vibrations to know where they come from, and then to really evaluate the performance of the tire and go to the limit. It happened later in Pedrosa, and it was glaring.”
So, for Pedrosa, we can say a small punctual defect?
“(Laughs) We are going to say wear and a totally abnormal appearance, which was not the case for all the drivers who had these tires. This is the observation. Now, you know, when we had Scott Redding's tire failure, there were a lot of other drivers riding with that tire at the back. Conclusions are difficult to draw without analysis so I avoid drawing them for the moment. And as a precaution, we will not bring this tire back to the other races until we have the results of the analyses, as we did with the Redding tire where we did not bring the same architecture . Well, we’re not going to bring that rubber back.”
To be continued…
Photo credit: Michelin
