Motegi Grand Prix debrief with Tohru Ubukata Round 2: Japan Post-race debrief Twin Ring Motegi, Tuesday 28 April 2009 Tyre compounds available: Slicks: Soft, Medium. Wets: soft After the second rain-affected race weekend of the 2009 MotoGP season, Bridgestone’s Tohru Ubukata reflects on rain, tyre choices and consistency. Q&A with Tohru Ubukata – Bridgestone Motorsport Manager, Motorcycle Race Tyre Development We saw a lot of heavy rain in Motegi. What can you say about the performance of the wet tyre? I am quite pleased with the performance of the Bridgestone wet tyre this weekend as we saw some very difficult conditions. The rain on Saturday was very heavy, enough to cancel the qualifying session because of standing water, and again it rained heavily on Sunday morning for the warm-up session. On Saturday especially the temperature was also cold, so generating tyre temperature becomes the challenge. The soft compound wet Bridgestone was the correct decision for this weekend. It was the first experience of wet competition also. It rained in Qatar but because of the glare from the floodlights, no wet running was conducted, so I am happy with their performance with all bikes. What are the big challenges in achieving good wet tyre performance? Firstly it is to remove the water from beneath the tyre so that it can get maximum grip from the surface. This challenge gets larger if there is lots of standing water, like we saw on Saturday. Because wet races are generally cooler, generating and moderating the correct temperature is also a challenge so that the tyre does not run too cool and not reach optimum grip. This consistency is crucial to give a good feeling to the riders over a race distance. What can you say about tyre performance this weekend? I am quite pleased about the performance of the Bridgestones because we have seen many conditions this weekend and with only two slick compounds and one wet compound we have been able to provide consistent performance throughout. From dry and cold on Friday, to wet and cold on Saturday and dry and warm on Sunday, just three tyre specifications have coped with all these conditions. I am happy that our one make tyres showed a much wider operating range this weekend and delivered good performance. Also, the medium compound slick tyres gave consistent performance throughout the race with the front riders doing their fastest laps in the second half of the race. Mika Kallio and James Toseland used soft compound rear tyres to both finish inside the top ten, and at a track temperature of 35 degrees Celsius I am happy to see this. We did see some problems with Dani Pedrosa’s medium compound front Bridgestone tyre after the race. All the other tyres that were used during the weekend, and this season, performed well so we can say this is a problem isolated to just this one tyre, but of course we have already taken the tyre to our technical centre in Tokyo where we are investigating the problem in detail. I would like to apologise to Dani and the Repsol Honda team, but we saw that despite the problem the front Bridgestone continued to perform until the end of the race and I am happy that Dani finished a great ride in third position. We have seen more variation in the riders’ tyre compound choices this weekend. How much difference does riding style make to tyre performance? There are two riding styles that I can define. The first is a focus on entry speed, and the second focuses on speed from the apex to the exit of a corner. Those riders who like to maximize entry speed usually prefer a harder compound front tyre to work best with their style. Riders who focus on apex to exit speed prefer a softer front and a harder compound rear tyre. These two styles work the tyres in very different ways. The weight of each rider can also affect compound choices. It is also important to consider that tyre performance is related to the individual behaviour of each bike and how it is setup to use the tyres. I think we will see this more during the rest of the season, and I think differences in compound choices will lead to some good racing.