Valencian Grand Prix, Cheste: Bridgestone Debrief with Tohru Ubukata

The finale of the 2011 season at Valencia was a thrilling but an incredibly tricky race for riders and tyres alike. The conditions were bad all weekend. Friday was wet but drying, leaving teams chasing setups on wet tyres as the track continually changed. Saturday’s sessions were dry although rain fell during the day, leaving the track greasy and slippery. Then on Sunday, spots of rain fell all day, sometimes harder and sometimes softer, meaning that the grip level continually changed, even corner by corner. At points during the race it looked as though the wet bikes may be required, but ultimately every rider made the slicks work for the duration. A crash into turn one on the first lap sidelined Alvaro Bautista, Valentino Rossi. Nicky Hayden and Randy de Puniet, and towards the end of the race the rain got heavier, allowing Ben Spies to eat into Casey Stoner’s huge early lead and ultimately take the lead, only to lose out by 0.015seconds in a drag from the last corner across the finish line. Andrea Dovizioso finished third to take third in the World Championship standings, and Cal Crutchlow was fourth to take the Rookie of the Year title.

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

Tohru Ubukata – General Manager, Bridgestone Motorsport Tyre Development Department

The conditions were very tricky throughout the weekend – how did this affect tyre performance?
“Really all weekend the track conditions were neither one thing nor the other. When the track was wet, it wasn’t really fully wet and it dried through the session leaving the teams to chase setup, and when it was dry it was still very greasy. In the race spots of rain fell throughout, which made it very tricky for the riders to gauge the level of grip available, as it was often different from corner to corner, and in such a situation tyre performance is always a compromise.

“Wet tyre performance was basically satisfactory in the conditions. Wear rate was higher as the track started to dry, but it was still at an acceptable level, although in such half-and-half conditions tyre performance is always limited. The biggest objective for us in this instance is consistency across the field so that everyone is faced with the same situation.

“I am also satisfied with slick tyre performance even in the slippery conditions during Sunday’s race when rain spots were falling. Wear rate was low as you’d expect when the grip level is also low so durability was not a concern, but it was a real test for the riders to judge corner-by-corner how much grip was available and how much to push. Front tyre performance and feedback is crucial in allowing the riders to feel the grip, and I am happy in this respect.

“Tyre selection for the race was very important with the conditions so borderline and the temperature low and we saw many riders change their tyre selection on the grid to choose the softer compound front slicks, favouring their improved warm-up performance. In this respect, the interaction between our engineers with the teams and riders was very important.”

Source: Bridgestone Motorsport