Valencia Grand Prix debrief with Tohru Ubukata

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

The last grand prix of the 2009 MotoGP season was won by Repsol Honda's Dani Pedrosa. It was the second victory for the Spaniard on Bridgestone tyres, and after Ducati Team's Casey Stoner crashed on the warm-up lap and was ruled out of the race, Pedrosa led from start to finish. The grand prix was held later this year than last and so conditions were cool, but still the harder of the available Bridgestone slicks were the favoured choice of the top four: Pedrosa, Valentino Rossi, Jorge Lorenzo and Colin Edwards. Although the top four all used the same tyre compounds, front tyre choices varied throughout the field. The top three in qualifying all lapped faster than the circuit lap record, but on Sunday the times were slower in the cooler and windy conditions.

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

What were the main challenges for the tyres during the grand prix weekend?

"Valencia is not a circuit that is particularly tough on tyres in terms of abrasion and durability, but it does demand a lot from the tyre shoulders because it is so twisty. The conditions all weekend were actually quite cool too, especially with the wind, so good warm-up performance was important, and this is why we brought softer tyre compounds as these reach their optimum operating temperature faster."

We saw strong winds on all three days - how did this affect the tyres?

"Coupled with the already quite cool ambient temperature, the wind had a great cooling effect on the tyres, and we saw some teams on the grid using wind shields to protect the tyre warmers from the gusts to ensure the tyres reached their optimum temperature. The wind also brought dust onto the track which made the surface more slippery in places. I must say though that the biggest challenge caused by the wind was for the riders themselves, as it made it very difficult to put together a good lap whilst being buffeted by the strong gusts."

Why did we see such a mix of riders using the softer front and the harder front tyre during the race?

"The track conditions and temperature were such that both the soft and the medium compound front tyres were working well so it came down to a case of rider preference and what worked best as a part of the rider, machine and tyre package. Some packages use the front tyre less hard and so could make use of the soft compound, but conversely some packages are optimised for the harder option. The soft front tyre has better warm-up performance and outright grip, whereas the medium compound offers better race distance durability and consistency."

How can you summarise tyre performance from this weekend?

"We can see from the mixed front tyre choices that the performance operating ranges of both front tyre compounds were sufficiently wide as to overlap, and engineering wide operating ranges was one of our objectives this season. The times during Saturday's qualifying session were good and the top three all lapped faster than the lap record so the performance indicators for Sunday's race were good, but track conditions changed slightly after strong winds and light rain on Saturday night and the race pace was slightly slower. Nevertheless, Dani's race time was almost the same as last year's winning time, so this shows that even though laptimes were slower the overall consistency was good. Overall, I am pleased with the performance of our tyres in the last race of our first season as sole tyre supplier."

-credit: bridgestone