German GP: Bridgestone post-race debrief

Bridgestone slick compounds available:
Front: Hard, Extra Hard.
Rear: Hard, Extra Hard (asymmetric)

The German Grand Prix was red flagged after nine laps because of a crash that involved Randy de Puniet, Aleix Espargaro and Alvaro Bautista, in which de Puniet suffered a fractured tibia and fibula in his left leg, and Espargaro a cracked vertebra. The race was restarted and run for a further 21 laps, meaning that the competitive distance was unaffected. Before and after the restart the battle for top spot was between Spaniards Dani Pedrosa and Jorge Lorenzo, who were both uncatchable. Ultimately it was Pedrosa who emerged victorious ahead of Lorenzo, whilst Casey Stoner pipped Valentino Rossi to the third step of the podium on the last corner of the race after a fantastic battle in the closing laps. The weather was typically changeable in Germany, and rain fell on Friday night and Saturday night, but the only session to be fully wet was Sunday's warm-up, which was the first full session of the season in which all riders used Bridgestone's wet tyres, although the initial laps on Saturday morning were wet too.

Q&A with Tohru Ubukata - Manager, Bridgestone Motorcycle Tyre Development Department

A special construction rear tyre was used at Sachsenring. Why was this?

"We used the same special construction rear slick in Germany this year as we do at Phillip Island, and it is designed specifically to be more durable under extreme tyre temperature. Sachsenring generates some of the highest front and rear tyre temperatures of the season because of the nature of the circuit and its abrasive tarmac, so race distance durability was our primary focus. We didn't bring this construction to Sachsenring last year, but after carefully analysing all the race data we decided it would be beneficial, and indeed the laptimes during the weekend were faster and consistency was better so I am happy with our decision and I think it demonstrates our commitment to continual improvement."

Why was this special construction not used for the front tyre?

"Rear tyre temperatures on average at Sachsenring are 20 per cent higher than front tyre temperatures, so there is no need to have this special construction for the front - our regular construction can cope well with the temperatures experienced even though for the front tyre they are the highest of the year. Rear tyre temperature is higher because of the extra loads and strains of transferring the bikes' power to the tarmac, especially through long and fast corners."

How was tyre performance during the weekend?

"The special construction in the rear tyrehelped tyre durability and consistency enormously, and that's the reason the softer rear could be used for the race with no problems. I am very happy about consistency as Casey set his best lap right at the end of the race, and overall the level of performance was high too as Dani, Jorge and Valentino set nine laptimes between them that were all were faster than the existing lap record, and Casey was only 0.009seconds from equalling this previous record too. Ultimately, Dani was the fastest man and beat his own previous record by over 0.2seconds."

Who made what tyre changes during the red flag period, before the race restart?

"Before the race was restarted, several ridersmade tyre changes, although only two changed their compound choices. Nicky changed from a softer to a harder rear and Marco Melandri chose a softer front in favour of the harder front he started with. Casey and Loris replaced their rear tyres with used items of the same compound but with fewer miles. Marco Simoncelli's front and rear tyres and Alex de Angelis' rear tyre were also replaced with brand new items of the same compound. But as Dani and Jorge showed, using the same set of tyres for both parts of the race was no problem and they were faster after the restart than before, so changing tyres was not a necessity."

-source: bridgestone