Bridgestone today issued their customary post-race press release, containing a debrief on the race just passed. This week, it is the turn of Shinji Aoki to explain the role which changing temperatures and hard braking played at Motegi:
Japanese MotoGP™ debrief with Shinji Aoki
Tuesday, October 14 2014
Bridgestone slick compounds available: Front: Soft, Medium & Hard; Rear: Extra-soft, Soft & Medium (Asymmetric)
Bridgestone wet tyre compounds available: Soft (Main), Hard (Alternative)
Movistar Yamaha MotoGP’s Jorge Lorenzo secured his second win in a row at last weekend’s Japanese Grand Prix as Repsol Honda’s Marc Marquez finished in second place to secure his second-straight MotoGP™ crown.
Conditions for the start of the Japanese Grand Prix race weekend were warm, but cool ambient temperatures and cloud cover drastically lowered track temperatures on Sunday, with a peak recording of just 27°C recorded during the race.
Q&A with Shinji Aoki – Manager, Bridgestone Motorcycle Tyre Development Department
How did the much cooler temperatures on Sunday compared to the previous days effect tyre performance during the race?
“We always have to be prepared for a wide variety of riding conditions and ambient temperatures when we design our tyre allocation for a race, especially for Motegi which at this time of year can be affected by adverse weather conditions. Our front tyre allocation for this year now includes three slick compound options and so this allows us to cover all our bases in terms of matching compound selection to cooler or warmer temperatures.
“For the asymmetric rear slicks, this circuit is severe on the centre section of the tyre in the numerous acceleration zones, but compared to the majority of other circuits we use relatively soft compounds on the shoulders at Motegi and this gives our tyres the ability to work in a wide range of conditions. What was really pleasing to see at Motegi was that the riders able to effectively use all of our slick tyres in the allocation, while showing incredibly quick pace throughout the weekend. A new qualifying lap record, race lap record and overall race time record at our home Grand Prix is an encouraging result for Bridgestone at our home race. This shows that no matter what the weather conditions, our tyres can provide very good performance.”
For the race all twenty-four riders selected the medium compound front slick. At a circuit which places so much emphasis on braking, why was this option preferred over the hard compound front?
“Of course the need for good braking performance at Motegi is an important consideration, but this is not only down to the front tyre it also requires good balance between the front and rear. We had feedback from some riders that for pure braking performance, the hard compound front slick showed excellent potential, however the medium compound front slick still offered good braking performance with better cornering performance than the hard option. Many riders also felt that they could achieve a better front-back bike balance using the medium front slick with the softer option rear slicks as well. Another factor which made the medium compound front slick the preferred option for the race instead of the hard front was the track temperature, which at the start of the race was thirteen degrees cooler than FP4 on Saturday.”
Apart from the layout of the Motegi circuit which places a lot of emphasis on braking and acceleration, are there any other characteristics about the circuit which influence tyre development for this circuit?
“The stop-and-go layout of the circuit is the main factor when we develop tyres for the Japanese Grand Prix as it places a lot of stress on the centre section of the front and rear tyres, but another consideration is the type of tarmac used at Motegi. The asphalt mix at Motegi provides a very high grip level, but it is also quite abrasive so we need ensure our tyre allocation for this race provides good performance and safety over twenty-four very tough laps. If you look at the lap times of race winner Jorge Lorenzo during the race, the difference in lap time between his quickest lap and the last lap of the race was only 0.6 seconds, so we definitely met our objective of ensuring our tyres were fast, consistent and durable.”