Round 4 France post-race debrief19/05/2009

Tyre compounds used: Front: Wets - Soft. Slicks - Soft, Medium.  Rear: Wets - Soft. Slicks - Soft, Medium  

Le Mans was the venue for the first wet race of 2009, although rain delayed the opening round in Qatar and flooded the qualifying session in Motegi. Demanding a mid-race switch to slicks as the track dried, riders used all three of Bridgestone’s tyre offerings during the weekend: the soft and medium compound slicks and the soft compound wet.  

Q&A with Tohru Ubukata - Bridgestone Motorsport – Manager, Motorcycle Race Tyre Development  

Bridgestone expected both dry and wet running in Le Mans, but how were these conditions prepared for?
We knew from past experience that the weather in Le Mans is unpredictable, but also that it is usually cool, especially when it rains. Because of this we brought the soft and medium compound slicks and the soft wets, just like we used in Motegi where the riders gained experience of wet running on these tyres.  

We also saw some big temperature differences during the sessions this weekend, but I am happy that with one tyre we have been able to cover the whole range. For example, the track temperature during Friday’s free practice was 20 degrees Celsius, but by the end of Saturday’s qualifying session it was 30 degrees, yet riders still could use the same compound with no problems. This is a big temperature window for just one compound of tyre so I am happy with this.  

What are your thoughts after the first wet start to a race this season?
I can say that I am very happy with the performance and durability of the Bridgestone wet tyres after this weekend. The conditions were not perfect, neither completely wet nor completely dry. At the start of the MotoGP race, the rain had stopped and although the track was wet, it was drying quickly. We saw that the wet tyre got faster and faster with each lap, even though the track was drying.  

Normally, you might expect a drying track to be slower for wets, but ours performed well with good consistency and durability, and actually got faster right up until the point that the track was dry enough for slick tyres to be quicker on lap nine. We used the same soft compound Bridgestone wet tyre both in Motegi, where the track was very wet and there was a lot of standing water, and in Le Mans where it started damp and dried, so this shows that the same tyre performs well across all types of wet conditions.  

Since Motegi we have also learned more about Dani’s front tyre. After a detailed inspection, we found a small foreign object that had become embedded within the tread of the front slick. This was the origin of a weak point in the tread of the tyre which, during the course of the race, worked its way to the surface, causing a crack to form in the rubber.  

The conditions for the race were damp but drying. How did the wet tyres and the slick tyres cope?
We saw this weekend that the wet and slick Bridgestone operating windows overlap, meaning that riders can use the wet tyre with good performance until the track is dry enough to comfortably use the slick tyre. For example, Jorge Lorenzo stayed on wet tyres until lap 12, whereas Marco Melandri switched to slicks on lap six and Dani Pedrosa even earlier on lap five, yet their lap times between these stops were comparable. This shows clearly that there is sufficient cross-over between the Bridgestone wets and slicks.