Bridgestone San Marino Grand Prix debrief with Hirohide Hamashima
The San Marino was won by Yamaha’s Jorge Lorenzo who sealed his third victory of the season to close in on Casey Stoner in the championship standings after the current leader finished third, just behind Dani Pedrosa. This means Stoner’s championship lead is now 35 points with 125 points still available from the remaining five grands prix. The weekend was very hot and humid, and although a few rain drops fell on Friday and again on Sunday at the start of the race, conditions remained dry. It was the first time that Bridgestone had selected asymmetric rear slicks for Misano in the single tyre era, and the laptimes were fast. Already from Friday morning the leaders were under the lap record, Stoner set a new pole position record, and Lorenzo set a new lap record.
Bridgestone slick compounds available: Front: Soft, Medium, Hard. Rear (asymmetric): Medium, Hard
Hirohide Hamashima – Assistant to Director, Motorsport Tyre Development Division
This year asymmetric rear slicks were selected for Misano – what effect did they have?
“I think that we can see clearly from the laptimes that the pace was much faster this year, and whilst we cannot attribute it all to our tyres, we can at least say that the asymmetric rears offered a distinct performance advantage. To be under the lap record from the very first session of the weekend on a Friday morning is very unusual and impressive indeed and that pace continued for the weekend. In qualifying, Casey set a new pole position record, and in the race Jorge set a new lap record and new total fastest race time. This shows us that outright grip was high and durability and consistency over race-distance were also good.
“The objective of selecting asymmetric slicks for Misano this year was to increase rider feeling and thus safety on the lesser-used left side of the rear tyres and to offer a performance advantage, and I can happily say that I believe we achieved both of these.”
Many lap records have been beaten since 2009, so why is it such a big deal to set a new pole record?
“Simply because most of the current pole position records were set before the single tyre situation started in 2009, so in the era of tyre competition. This was when qualifying tyres were used – designed to provide maximum grip at the expense of durability, lasting only a handful of laps. From our experience, qualifying tyres are in the region of one second a lap faster than race tyres. Now, since 2009, we no longer use qualifying tyres so Casey’s pole position record was set on race tyres. This is only the eighth pole record that has been set since 2009 and of those, two were at Silverstone and Aragon which were new circuits last year, one was at Assen which was shortened by 13m in 2010, and two more were at Mugello and Indianapolis which had new and improved surfaces. Of course, this cannot be credited just to tyres and this improvement in laptime also demonstrates the hard work of the manufacturers in improving machine performance year-on-year.
“This gives an idea of the level of performance during the San Marino GP over the weekend, and I am very pleased indeed with this, especially as we saw that exactly the same tyre compounds as used by Casey on his pole record lap were used in the race to set a new best total race time, so clearly the additional performance of our asymmetric rear slicks was not at the expense of durability. I believe this shows the level of development we are still doing with our MotoGP tyres, and that we are not simply standing still now there is no tyre competition.”
Source: Bridgestone Motorsport