Valentino Rossi's first victory of the season means MotoGP has now enjoyed three different winners and three different championship leaders in as many races in the single tyre era. Q&A with Tohru Ubukata - Bridgestone...
Valentino Rossi's first victory of the season means MotoGP has now enjoyed three different winners and three different championship leaders in as many races in the single tyre era.
Q&A with Tohru Ubukata - Bridgestone Motorsport - Manager, Motorcycle Race Tyre Development
What was the biggest challenge for the tyres in Jerez?
During the IRTA official pre-season test at Jerez the track temperature was around 34 degrees Celsius, so over the weekend we had an extra 15 degrees of temperature for the Bridgestone slicks to deal with. Extra heat like this is more demanding of the rubber as it makes the tyres run much hotter. The hotter tyres get, the more the rubber starts to move and this makes the tyre's temperature rise even faster, so it can be a big challenge. However, we were able to use the same compounds in both the test and the race with no problems so this is another example of the wider operating temperature range of our tyres for this season.
As well as this, the track has been resurfaced since last year and made more abrasive, so demands more of the rubber. The more abrasive the track and the more grip it offers, the more it loads the tyre and this is another element that generates more heat in the rubber. We saw though that the Bridgestone slicks had very good durability and consistency for the race distance, especially as riders were pushing hard in some close battles right to the race finish, such as Jorge Lorenzo chasing Casey Stoner and the battle between Marco Melandri, Loris Capirossi and Colin Edwards. When riders are pushing in a close race, this always demands more of the tyres.
How and when were the compounds chosen for the weekend?
We decided before the start of the season that we would bring the soft and medium compound rear Bridgestones and the hard and medium compound fronts to the race. We brought the exact same tyre compounds to the pre-season test here at the end of March, and this test confirmed that we had made the right choice for the race. Expecting that the temperature would be hot this weekend, we intended well in advance to bring the hard compound front tyre to this race.
How did tyre compound choices between qualifying and the race differ?
Most riders tried the hard front and medium rear tyres in qualifying, but the fastest laps were done using the hard front and soft rear tyre for extra traction over a shorter qualifying distance. For the race, everyone used the hard front tyre as we expected, and most riders used the medium compound rear for extra durability over the 27 laps, especially as Sunday was the hottest day of the weekend for track temperature.
Nicky Hayden, Mika Kallio and Niccolo Canepa all kept the soft compound rear however to try and achieve a better match with the characteristics of their bikes and setups. Nicky and Mika seem to favour the soft rear compound as they also used it in Motegi. These three riders had no problems with the soft rear even with these track conditions so this is also a good demonstration of the durability of this year's Bridgestones.
So far this season in all three races we have mainly used the medium compound rear Bridgestone even though each track has had a different character and there has been wide temperature variation. We haven't been able to use one tyre in so many different conditions in the past so this shows the wider operating range of the 2009 Bridgestones.
Tyre compounds available: Front: Medium, Hard. Rear: Soft, Medium