Bridgestone Press Release: Hirohide Hamashima Talks About Wet Weather Tires

The Bridgestone press office released the following question and answer session with their Director of Motorsport Tire Development, Hirohide Hamashima:


Spanish Grand Prix debrief with Hirohide Hamashima

Round 2: Spanish GP – Post-race debrief
Jerez Circuit, Thursday 7 April 2011
Bridgestone slick compounds available: Front: Medium, Hard. Rear: Soft, Medium
Bridgestone wet compounds available: Front: Soft. Rear: Soft

The Spanish Grand Prix started with the bright sun and fine weather the Andalucían venue is known for, but on Sunday the rain arrived and the first European GP of the season was also the first wet race since the Malaysian GP in 2009. Early on in the weekend the laptimes were very fast and several riders dipped under the lap record. The race however started wet so every rider used Bridgestone's wet tyres for the first time since the Portuguese GP last year, but as the track started drying by the end of the race the conditions became very tricky. The race was punctuated with crashes with several of the front-runners falling, handing Jorge Lorenzo a dramatic victory ahead of Dani Pedrosa and Nicky Hayden.

Q&A with Hirohide Hamashima – Director, Bridgestone Motorsport Tyre Development

The laptimes in the dry were very impressive, especially during qualifying. Why were they so fast?

"Track conditions were good on Friday and Saturday which was a large factor, and the temperature was also neither too hot or too cold. Immediately on Friday morning the times at the front were fast, although free practice two on Friday afternoon was slower as by then the wind had picked up and was quite strong, and the gusts made it difficult for the riders. But again on Saturday morning in the final free practice the times were very fast again. On just his second flying lap Dani Pedrosa was faster than the existing lap record, and his third lap was 0.9seconds faster than it. By the end of the afternoon's qualifying session, Casey Stoner was a full one second faster than the lap record, so from this I can say that clearly slick tyre performance was good, coupled with a track temperature of 33 degrees Celsius, good track conditions and very little wind. It also demonstrates the result of the development work undertaken by the teams over the winter."

The race of course was run on wet tyres though which was the first day of wet running this season. What challenges did this pose?

"Well the morning warm-up session was the first time that the teams have used our wet tyres with their 2011 bikes, and also for the MotoGP rookies it was their first time riding in the wet on our tyres too. The warm-up gave them just 20 minutes of running to arrive at good setups for the race which was a great challenge, despite the fact that all manufacturers have a great deal of data at the Jerez circuit from past races and tests here. From our side, the main role was to work closely with the teams and riders to support them in their setup decisions and provide them with any data that we could to help with this process. There was no concern for tyre selection however as under the current regulations we can only select one wet tyre compound for each grand prix, so every rider must use the same."

The race itself was very difficult, both for riders and tyres, because of the conditions. What can you say about wet tyre performance?

"Actually I can say that I am satisfied with the way our wet tyres worked in very difficult and demanding conditions. For sure tyre wear was quite high, but this is because the circuit was becoming increasingly less wet throughout the race and the tarmac at Jerez is abrasive, both of which lead to a higher level of tyre wear. The grip level dropped throughout the race but it did so consistently which made it a little easier for the riders to manage. I can say that the conditions we saw in Jerez were unusual and very tough for our tyres; the toughest situation we can expect to see. I am happy with our wet tyre selection too because compound selection is always a balance between grip level and tyre life, and in such slippery conditions the soft wets provided more grip and riders will always prefer a safer level of grip rather than a tyre that can last much longer but offers no traction. Even if we had the hard compound wet available in Jerez, I believe not many riders would have chosen it because the start of the race was full wet, and even if they did in such tough conditions it would only have given a few more laps."

 

2011

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Comments

I think that Bridgestone should have a medium rear wet tyre because the rears carry all the load and more likely to fail in such conditions where the spinning rear tyre eats the tread. A soft front can stay because of the tendency of the front to wash out in the wet conditions so as much grip is needed as possible. Highsides are unlikely with a good traction control setting so a medium rear won't hurt.

The factories should have enough traction control to stop the rear tyre from spinning up but still give good acceleration and there should be some knob or other device that the riders can adjust the traction control on the fly to adjust to the changing conditions. Ala Doivizoso.

afaik all the crashes were due to front end losses.. even simoncellis hi side started with him losing the front. to me that says the issue was more with the fronts.
you can have all the traction control you want but it wont stop you from folding the front if you're asking too much into a corner
thats not to say a medium wet isnt a good idea. i just think with the current tyre rules bridgestone cant afford to carry that many different compounds

as the big brother computer controls everything..how many power induced highsides were there?..it's all in the brakes, or not ha-ha.

Frankly, who needs a wet weather choice if Jerez is typical of the action it throws up?

...that's about what happened. Lorenzo, Pedrosa and Hayden on the podium? Those guys are all known for their precise control...and it would have been Edwards were it not for that snake bite on his ass whilst anywhere near the front!

A big +1 to your sentiment.

George made a very valid statement.He said they would welcome an option between a hard wet and soft wet option.
In all fairness,Bridgestone did a great job,but were stuck between a rock and a hard place on the day. We all knew the rain was comming Sunday PM.
They provided the best they could and had available on the day.
The abrasive surface,spotty rain, was out of their hands.
The rest was up to the riders,their racecraft and their equipment/setup.
On the day,Stoner,Pedrosa,Lorenzo,Hayden,Hiro and Spies fed themselves into the race.
Rossi and Simmo smelled blood and charged their way into it.It is really sad that the event was washed out as a result of indescretion in unchartered waters.
Once Stoner was capped and Simmo crashed, it was always end of the hunt for Lorenzo.
A little cost cutting may be in order. Draconian if you like.
Choices: You name them. Adapt the bike and rider to the rubber that keeps them on track......
Hard slick front and rear.
Intermediate front and rear.
Soft wet front and rear.
Too spoiled for choices,this generation of GP riders.

I know this is a repeat of what has been said, BUT, since we have this new rule system, (well....not so new. It has been a little while). The tire selection has gone down to a more sane level. But having just one selection for Rain, or WET tires may need to be looked at. Yes alot of riders just jacked up and crashed. But the tires did degrade badly. If they are stuck using just wet or dry tires then maybe riders should get a choice of two sets of wets like they do the dry. If it is dumping rain then the tires they had would be fine. But if it is spotty then they should be able to at least choose a harder tire. It too will be shredded at the end of the race, but it will last a little longer.

Normally, I would just say, "You are pros, ADAPT!", but in this case, I kind of felt for the riders and their struggles in braking and cornering. It looked like very few of them knew what would happen from corner to corner. Once they were able to stand it up they were fine. But going in to the corner as well as through the apex, I could bet money many of them were holding their breath until they knew they made it out of the corner completely.

I have just been looking at the lap times from Jerez & pretty well every rider made their fastest lap from 4-7. The drop off after that was consistent & at the end of the race the lap times were 5-8 seconds slower than the fastest lap.

Bearing that in mind why didn't anybody come & change bikes for a new set of tyres? I figure 30-40 seconds to come in & change bikes which would have been made up with interest in 6-8 laps.

It is a new concept for MotoGP to have a pitstop but in car racing when the track conditions are bad you have to be on the best tyres for the conditions no matter how many times you stop. Any thoughts?

FROM MotoGP website, the last paragraph being the most interesting, given no5isalive's comment above. (There is an obvious error regarding the omission of Motegi as a wet race in 2007):

WET RACES
For wet conditions, special wet tyres with full treads can be used, but they deteriorate quickly if the track dries out

Races are categorised as either wet or dry before they start, but a white flag being waved at the flag marshal post during the race indicates that the Race Direction have decided to declare a wet race after it was originally declared dry.

Thus far having been introduced in 2005 the white flag rule has only been enforced three times and the first instance at the GP of Portugal in 2005 took place so late in the race that the riders stayed on their dry bikes. However, at Phillip Island in 2006 and Le Mans in 2007 the rain fell early and heavily enough to warrant a change of bikes, which led to the dramatic spectacle of the entire MotoGP grid entering the pit lane mid-race to swap machinery.

The rules also dictate that once a race is declared wet from the start, a rider can come into the pits to change bikes whenever he decides as long as the type of tyres to be used is different.

Thanks for your input Baron, I did a quick check of the rule (More to confirm that it still existed) & I did not see the part about having to use a "different type" of tyre if you stop mid race. My line of thought was to change to a fresh set of wets for the second half of the race & use the superior grip of the new tyres to move to the front of the field. When Dovi stopped & changed bikes with 9 or 10 laps to go (to slicks presumably) he went back to doing 1.50's while the leaders were doing 1.55's to 1.58's.