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.”
“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 and so good
warm-up performance is important"