Bridgestone Press Release: Masao Azuma Talks Heat Resistant Tires At Assen, And Testing In Argentina

Bridgestone has issued their customary post-race debrief after the Dutch TT at Assen. In this edition of the press release, Bridgestone talk about how tires designed to work under heat-resistant conditions functioned in Assen, and about testing tires at the new Argentinian track at Termas de Rio Hondo. The press release appears below:

Dutch MotoGP™ debrief with Masao Azuma

Wednesday 3 July 2013

Bridgestone slick compounds available: Front: Extra-soft & Soft. Rear: Soft, Medium-soft & Medium (Asymmetric)

Bridgestone wet tyre compounds available: Soft (Main), Hard (Alternative)

Yamaha Factory Racing’s Valentino Rossi claimed his 80th premier class victory after winning last Saturday’s Dutch TT ahead of Repsol Honda’s Marc Marquez and Monster Yamaha Tech3’s Cal Crutchlow.

Following a very hot race at the previous round at Montmeló, weather conditions at Assen were at the other end of the spectrum, with cool and at times, wet conditions occurring over the race weekend. Thankfully, fine weather prevailed on Saturday, with a dry circuit and a track temperature of 32°C recorded during the twenty-six lap race. This year marked the first time Bridgestone supplied heat-resistant ‘Special Construction’ rear slicks for the Dutch TT.

Q&A with Masao Azuma – Chief Engineer, Bridgestone Motorsport Tyre Development Department

This year’s Dutch TT experienced variable weather conditions. How did the cool temperatures, wind and rain affect tyre performance and did the weather forecast influence the tyre allocation for this race?

“The weather last weekend was quite typical for Assen, but we have also had quite warm temperatures here in the past so we had to consider many possible weather conditions for the race. We felt confident that our rear tyre allocation, which was made up of heat-resistant rear slicks could handle any possible weather condition for the race weekend, but for the front slick tyres we had to wait until the day before practice before deciding which compounds to offer. Finally, we made the decision to offer our softest front slicks – the extra-soft and soft compounds – as we knew there would be a need for good warm-up performance and grip at this event. We also nominated the soft compound wet tyre as the main wet weather option as this is best suited to cold, low-grip conditions. I feel that our tyre allocation was ideal for the challenging conditions and the encouraging feedback from the riders showed us that we made the right choices.

“The harder option rear slicks were not used over the race weekend, as the only conditions where we might have seen them used was for the race as this was the warmest day. However, as no one evaluated this option in practice, none of the teams had data on how it would perform and so it didn’t appear during the race. The harder front slick was the popular choice for the race, with only two riders selecting the softer option. The warmer track temperatures on race day saw many riders who were originally planning to run the softer front option switch to the harder front as the need for warm-up performance decreased. At a circuit like Assen which has many fast sections and changes of direction, a stable front-end is very important and the warmer track on Saturday enabled more riders to select the harder front slick which offers greater stability.”

Bridgestone brought its Special Construction heat-resistant rear slicks to Assen for the first time. How did these perform last weekend?

“The heat-resistant rear slicks performed really well. The low grip level of the circuit meant that the teams had to work hard to find a setup that could maximise rear grip and as some riders feel a slight decrease in edge grip with this specification, it made finding a setup a bit more challenging. However if you look at qualifying and the race, the pace was very good and everyone was able to push hard from early on which made things very exciting. The primary reason we introduced the heat-resistant rear slicks at Assen was to improve rider safety, and as we had no heat-related tyre issues this year it was definitely the correct decision to make this change.”

Bridgestone is now in Argentina to provide tyres and technicians for the Rio Hondo test. What tyre options have been brought to the test?

“We received preliminary data from the circuit designers on the layout and tarmac composition of the circuit and it is obvious that Rio Honda is a very fast circuit with lots of high-camber corners. We have undertaken performance simulations at our Technical Centre in Japan and expect this track to be one of the harshest events on the calendar for tyres, as there is the potential for very high tyre temperatures to occur. However, it is winter in the southern hemisphere so track temperatures will be cool, so we must also provide the riders with good warm-up performance.

“With so many performance and safety considerations, we have brought numerous tyre options to Rio Hondo. Particularly for the rear slick tyres we are providing many options; we have symmetric and asymmetric rear slicks in a variety of rubber compounds, and have brought each of these options in both our regular and heat-resistant Special Construction specification. We will ask the riders to evaluate as many of these tyres as possible to give us a comprehensive data set that will help us develop the right tyres for next year’s race at this circuit”

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Azuma's explanation for the heat-resistant rears at Assen doesn't hold water. Assen is not the same as Mugello, which Azuma said the heat-resistant rear was designed for. Bridgestone said Mugello was the only track scheduled for the heat-resistant rear this season because of the high temperatures expected there in combination with the number of fast, high energy corners.
It was cooler than normal at Assen and low-and-behold there were the heat-resistant rears again!
It's been well documented that the Hondas at high lean angles react badly to the different construction of the heat-resistant tires, losing edge grip. It will be interesting to see if Bridgestone now brings these heat-resistant tires to all the suggested "Honda" tracks during the rest of the season.
Yamaha seems to have a ready friend in Bridgestone!
Bridgestone has never complained, to my knowledge, that the Winter testing season is not sufficient to develop safe race-worthy tires for the season. There should be no reason to introduce new tires after the race season has begun. When Bridgestone talks about positive rider feedback, I wonder who they are talking to? Do they only listen to the positive feedback or are they just selective in their listening? IMO there needs to be more transparency in Bridgestone's relationship to Dorna and the factory teams. Also, Dorna should be concerned that the spec tires are not used to manipulate the racing and should take strong steps to see that this doesn't happen.

Total votes: 47

with Spies' and Rossi's tyres literally throwing chunks off themselves? I guess their idea was to avoid a repeat of that. Better safe than sorry.

I don't see how Bridgestone can be accused of manipulating racing. Look at how many options and different tyres they have mentioned in this press release alone. A little more and they will have thrown a dozen of tyres possible, plus the kitchen sink, for teams to have tested and used in a very limited ammount of time (and still very different track conditions). Even if some choices are not unanimously met with praise from the teams, there is only so much they can do.

I am pro-Bridgestone biased, but still...

Total votes: 39

There was blistering and chunking last year at Assen, so Bridgestone brought in the heat resistant tires this year, hence no problems. The decision to bring these tyres was probably made the Monday after last year's race.


Total votes: 43