A Crash.net feature by Bridgestone's Tom Tremayne...
In a break from the norm, on the eve of what could be the deciding race in the 2009 MotoGP World Championship, Bridgestone's Manager of Motorcycle Tyre Development talks about the rubber that has been at the heart of the action all season.
“The single tyre status required development from a different point of view for us” says Tohru Ubukata. “In previous years our most important objective was to win races against other tyre manufacturers, so sometimes we developed tyres which were designed to improve specific characteristics. But this year, the primary objective has changed. Now we are required to produce tyres which offer consistent performance, and to provide them fairly and equally to all teams.”
Some may perceive that the dawn of the single tyre era means that Bridgestone has taken more of a back seat in the competition, but this couldn't be further from the truth as each team's tyre engineer works closely with team engineers and riders throughout the weekend.
“Though it is not difficult to produce tyres that fit all teams, it is not easy to produce tyres that satisfy all of them. Therefore we are also trying to add to our role by being good advisors on tyre usage, instead of just being suppliers and engineers. We are more able to focus on reviewing the data gained from the respective teams which will help us accumulate knowledge about the characteristics of their bikes to help them more in future, and so on.”
Tyres have always been of a black art, not generally understood but their ability to perform taken for granted. This is perhaps particularly true in the case of motorcycle tyres, which are placed under very different demands than car tyres.
“The contact patch areas of four-wheeled vehicle tyres basically remain same: almost the entire width of the tread is in contact with the road surface while they are travelling through either right-handers or left-handers. With motorcycle tyres however, they lean to the side on corners. When they run on a circuit with many right-handers, where mostly the right side of the tyres is in contact with the surface, it is the right side that gets more wear, and vice versa on a circuit with many left-handers.
“To give you an extreme example, some of our MotoGP tyres are composed of different compounds on each side to compensate for an imbalance between right and left corners and thus the loads placed on the left and right sides of the tyre. We call these asymmetric tyres. Although we don't need to use these in Sepang, they were needed in Estoril and Phillip Island for example, and will be used finally in Valencia.”
As was the part of the objective for appointing Bridgestone as the Official Tyre Supplier to MotoGP, the competition has been closer this year and it has taken until the penultimate round, here in Sepang, before there has been a real chance that the World Championship title can be decided.
As Valentino Rossi
looks on the verge of claiming his seventh premier class title, and his second consecutively on Bridgestone tyres, the pace at Sepang has been as hot as the track temperature.
“During this season's Czech Republic Grand Prix, for the first time this year a new pole position lap record was set. This was significant as this year there are no qualifying tyres, so riders must qualify on race tyres, yet the previous qualifying record was set in 2006, using 990cc bikes and qualifying tyres. The same has happened again here in Sepang today when Valentino beat his own existing 990cc pole position record, showing at least in part the advances that have been made this year with bikes and tyres.
“This year has been a challenge for us in many ways, but it looks at though the 2009 World Championship title could soon be decided, I can say that I am happy with what we have been able to achieve this season, and generally the teams and riders seem happy too. The racing has been very close this year, so I hope that the fans are also happy with what they have seen!”