Bridgestone Press Release: Masao Azuma On Possible Reasons For Silverstone Warm Up Crashes

Bridgestone's customary post-race press release after the Silverstone round of MotoGP offers two items of note. First, pleasure from the Japanese tire company that the tire selection for the race was much more mixed than usual. And secondly, a theory and an excuse for why some of the crashes happened during Sunday morning warm up. The press release appears below:

British MotoGP™ debrief with Masao Azuma
Wednesday 4 September 2013

Bridgestone slick compounds available: Front: Soft & Medium. Rear: Soft, Medium-soft & Medium (Asymmetric)
Bridgestone wet tyre compounds available: Soft (Main), Hard (Alternative)

Yamaha Factory Racing’s Jorge Lorenzo rode one of the races of his career at Silverstone last Sunday to claim a special victory over Repsol Honda’s Marc Marquez and claw back valuable points in his MotoGP™ title defence.

The decision to shift the British Grand Prix from June to August was a masterstroke with the event enjoying fine weather throughout the three days of on-track action. A peak track temperature of 32°C was recorded during the race and tyre choice for the race was varied with all slick options being used and a significant part of the grid lining up on harder rear slick options.

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

The qualifying and race lap records at Silverstone were smashed last weekend. Can you explain this big improvement in the general pace of the MotoGP bikes at this circuit?

“A lot of the improvement had to do with the dry, consistent weather we had over the weekend. This enabled the teams to find a setup that got the most out of the tyres and put it good use when it was needed most. We knew the one-thousand cc MotoGP bikes had the potential to go extremely quick around Silverstone and with our tyre allocation for this race featuring rubber compounds towards the softer end of the scale, the potential for a big reduction lap times was good. However, to see the existing Circuit Best Lap record beaten by almost two seconds in qualifying and the Circuit Record Lap lowered by almost a second in the race was outstanding. It is good to see such pace over a lap but for Bridgestone, we were most pleased with the overall race time which was about twenty-four seconds quicker than last year, representing an improvement of over one second per lap compared to the previous best time. This shows that the high pace was maintained through the race with a minimal degradation of performance over the twenty laps.”

There was a lot of variation in tyre choice for the race, both for the front and the rear. Can you explain what it is about Silverstone and the tyre allocation for this race that caused this?

“The rear tyre allocation for Silverstone is like the circuit, quite unique in that for the works riders we use the same, medium rubber compound on the ‘harder’ shoulder, which is the shoulder that is placed under the most stress while cornering which for this circuit is the right shoulder. We do this because our data indicates that the stress placed on the right shoulder is not so severe, so we don’t need to go harder than the medium compound on that shoulder. However, our asymmetric slicks need to ensure good temperature retention and warm-up performance on the lesser used ‘softer’ shoulder, which at Silverstone is the left side, so we use softer rubber compounds on that shoulder. So even the hardest option rear slick at Silverstone featured the medium rubber compound and as this compound has proved very popular this season. Another important factor was that all the afternoon sessions featured the same weather conditions and we had no rain. We have had a few instances this season where the harder rear slicks have been used in the afternoon practice sessions, only for conditions for the race being cooler, which has dissuaded the riders from selecting the harder rear slicks.”

The number of incidents seemed to increase in the morning sessions. Was this just because of the cool weather or were there other factors at play?

“Cooler temperatures always create more challenging conditions, there is no doubt about that but Bridgestone has made a big effort in recent seasons to improve both the warm-up performance and feel of our tyres to reduce risk in cooler temperatures. On Friday, MotoGP was the only class not to have any crashes in the morning session and on Sunday morning, three of the five crashes happened at Vale which features a small dip which can unsettle the front of the bike in what is quite an extreme braking zone. This point of the track has always been challenging for the riders, and the cold weather exacerbated the situation. As always we will examine rider feedback, tyre and telemetry data to see if changes need to be made for the future, but with the harsh braking zones at Silverstone if you go too soft with the compound selection, braking stability can become an issue. Front tyre selection at Silverstone is always a juggling act, and I believe we got the balance right but there is no denying that in cool conditions, parts of the Silverstone circuit will always be difficult for riders to manage.”

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Bridgestone's attitude to crashes and the safety of riders is appalling. If Dorna don't dump them at renewal time I would be very disappointed.
The relevance of these tyres to road use seems questionable and it would be better to bring a more road-orientated type of tyre that is not absolutely unique to this category.
I wish we could get one of the riders or team technicians to talk about this issue and what they think would improve both safety and competition. A sort of StickiLeaks.
Cal's view of this 'report' would be interesting I'm sure.

Reports on other sites indicate Nicky Hayden has tested the WSB Panigale. One quote I've seen says "According to a factory source, after his shakedown laps Hayden got off the bike and manually prodded the front tyre to see if it should be that soft and move around as much as it did."

Their MotoGP tyres are clearly like their road tyres - hard as concrete and take forever to warm up. Bring on a tyre war! I also think it's absurd that MotoGP is being forced down one technological direction because that's the only way to get them to work on the tyres. Would the Ducati be more competitive with softer tyres?

Would love a tire war. Spec racing removes the tech race from the program. Closed motors and spec tires will never get my vote. Never mind the honda cup in moto2 or the CRT shenanigans. I like the mechanical inovation as much, if not more, than cheering on the riders. Maybe otherwise - if I was from Spain.

The Ducati did best when Stoner was riding it with BS tires and most others had the M tires.

Now we have locked in results because we have locked in machines and tires. The big news now is when a rider paints their helmet a different color.

The Single-Tire Rule was created to reduce the ever-elevating drama over who had the best tire (brands) and the best picks from those brands for each team/rider! Think back to 2005/2006 when Bridgestone (vs Michelin) was the tire of choice for the riders! Riders complained over who got the best tires, first picks, etc etc. Add more tire brands? If MotoGP wants more drama? Then sure. Add Dunlop and Pirelli to MotoGP only. At least then Ducati will be more competitive for Crutchlow.

How about they allow ANY tyre to be used from ANY of the tyre makers?


a. 2 hours before the race all team's race tyres are impounded;

b. 90 minutes before the race a 'tyre claiming rule window' is allowed; (an arbitory but substantial e.g. $10,000)

c. 60 minutes before the race the tyres are given to the claiming team or returned to original team

d. the team losing the tyres may recieve the same tyre from the manufacturer

e. Tyres claimed or impounded MUST be used by he race teams involved

It would allow 'midnight specials' but risk them being used by others... Makes more sense than the CRT rules do at the moment.

I don't foresee becoming reality but it has itw own sense and it could be worth exploring. But I don't see any benefits for "them" so.....

I think that'd be a great situation. But how does say Michelin deal with the situation where every team claims Rossi's tire choice? Unless Michelin brought enough to share with the whole class, someone's going to be unhappy.