Pirelli To Bring Stiffer Rear Tire To Laguna Seca To Stem Tire Issues

The Misano round of WorldSBK was dominated by talk of tires. As such, following a weekend fraught with failures, Pirelli will revert to an older specification of tire for the Laguna Seca round. The move sees Pirelli at a crossroads, after a series of high profile incidents during the scorching weekend in Italy.

This includes Michael van der Mark's crash from the lead of Saturday's race, after a tire failure saw the Dutch rider robbed of his chance to claim his first podium for Yamaha. One has to remember too, Jonathan Rea also crashed out of the lead at the previous round in Donington Park, as it was a shock to see the previously robust Pirelli fail once again.

"Johnny was using the V0602 tire, which is a development SC0, but Van der Mark was a standard SC0 tire," said Pirelli's Communication Manager, Matteo Giusti.

"The standard has been available for more than one year and has been used many times. They were two different tires and two different problems with different damage to them.Johnny had a tear in his tire that was about 10cm along the side of the tire whereas Michael had a small hole in the surface. With Mickey's tire you can put your finger through the tire but we are not sure what happened to cause this on the tire."

Pirelli separates its tires by their family of compound. In the case of the tires that suffered the issues, they were the SC0 compound. Within those tires, things get divided further, as there are 'standard' and 'development' tires within the family.

A new tire is a development tire until it is available in a shop, when it then becomes the standard tire. In the past, Pirelli has been able to show tremendous reliability, and while the incidents could be looked at as being a mere coincidence, the issue reared its head once again on Sunday. With lap times tumbling in WorldSBK, the tires are being placed under ever more strain, and suddenly what was once well within the operating window for them is no longer quite as comfortable.

Jordi Torres, who led for more than half of Race 2 on the BMW, was given a reminder of this fact when he was robbed of a podium by the same issue that had hit Van der Mark. The Dutch rider also had a repeat issue with his Pirelli in Race 2.

Jonathan Rea's crew chief, Pere Riba, offered his opinion on the issue at the conclusion of action on Sunday. "The temperatures that we had this weekend meant that the rear tire became quite critical for everyone," said Riba. "Johnny had an unbalanced tire. From the data and Johnny's feedback from lap three he started to have a big vibration on the tire that got worse and worse."

"In the last five laps Johnny became quite nervous because the chatter and vibration became worse, and his mind was thinking back to his problem in Donington. It made Johnny nervous and he was a little bit scared in some of the faster corners. Having had his crash in Donington, and Van der Mark crash in front of him yesterday, it was probably too many things happening for him. It's difficult in that situation to ride the bike."

While Rea had a vibration that was caused by the tire rotating 180 degrees on the wheel rim, it was not the same issue that affected Torres. The Spanish rider had the same problem as Van der Mark, with a small hole in his tire. "The rear tire vibrated for me," commented Torres after the race. "It has happened to me before, and I have stopped rather than risk a crash. It's disappointing to have this tire problem because we were running well in the race."

"Many riders had problems with the rear tire this weekend. I tried not to push too hard, but maybe the temperature played a role because it was so hot here."

The heat from the blowback from a series of tire problems has certainly affected Pirelli, and for Laguna Seca the Italian firm will revert to an older specification of tire.

As such, Pirelli are hoping that everything will be alright in the Californian heat for the WorldSBK paddock. The tire supplier has taken the decision to revert to an older specification rear tire. The compound will be from the same SC0 family, but will have a much stiffer carcass to be able to deal with the issues that have arisen of late.

"Following what has happened this weekend in Misano we have decided to immediately cancel the delivery of tires to Laguna Seca," said Pirelli's chief Giorgio Barbier. "We have evaluated that we will use an older specification of the SC0 tire for the next round. This specification will be the 2016 tire, because following the problem for Michael van der Mark in Race 1, we also had problems with the rear tire for Jordi Torres and Van der Mark again today."

"We need to evaluate what is causing this issue because we also had a problem in Donington Park with Jonathan Rea," added Barbier. "The performance of a WorldSBK bike is very impressive, but maybe we need to evaluate using a different tire that would lead to a sightly slower lap time so that we do not have these issues in future. At Misano the issues we had were to do with blistering, the tire was suffering like it would at Phillip Island rather than here at Misano. It was strange and we need to analyze why it is happening, so it's best to revert to the older specification."

For Riba the weekend consisted of trying to understand the issue that his rider had at Donington Park and now to look to the future. "I think that it's the right decision from Pirelli to change the tire for Laguna," said Riba. "We will take a step back from the best performance possible, but I think it's the right thing to do, because we cannot keep going with this type of risk."

"Johnny, Torres, and Van der Mark have all had problems with the tires. I've talked to Giorgio about it to try and understand what is happening. Pirelli has said that they will make a new tire for Laguna with the previous carcass for the stiffness. The rubber will be the same as the V0602, the current development tire. It is the rubber that Johnny had the problem with at Donington, but it will have the stiffer carcass. It'll be a step backwards for performance, but it will be stronger from the carcass for us. This will mean that maybe the lap time will be slower but that is the correct decision to make, because safety is the most important thing."

As the control tire supplier in WorldSBK there is less pressure on Pirelli to develop new solutions than in the past when they faced competition. "Pirelli has made a great job of development in the last five years," continued Riba. "However, in that time, the rear tire has been developed very well with more and more grip, and it's very good and also very consistent. With more grip from the rear it means that there is more stress on the bike and the tire, but we are still using the front tire from four or five years ago. I said to them that, from my point of view, that tire is the most important thing for the performance and development of a bike."

"It dictates everything - chassis stiffness, suspension, engine, electronics - and I think that with the lap time coming from using all of the potential grip from the rear tire, it might be that we have a limitation with the front tire. The grip with the rear is so high, but with the older front tire maybe it cannot handle that much grip, because it hasn't been able to be developed at the same rate as the rear tire. That's not to say that Pirelli hasn't tried. We have had so many development front tires, but the standard tire is always the most popular for us. The balance front and rear at the moment I don't think is the best that it can be, but tire development is very complicated."

One has to ask whether there needs to be such a cutting edge tire in WorldSBK. In winter testing, the production machines have been as fast, or faster, than the MotoGP prototypes. The big question though is whether that is necessary. Last year, Alex Lowes gave his assessment. "A WorldSBK bike is a very fast machine, but now that I've ridden a MotoGP bike I can understand the differences," said Lowes.

"A MotoGP bike isn't that much faster over a single lap than a Superbike. In most cases it's a little faster in each corner, but over the course of a race those corner by corner gains make up a lot of time."

It's very impressive, and surely good marketing, to be able to show that a standard tire for customers is able to lap a circuit as fast as a MotoGP bike, but with the issues that Pirelli has had, the Italian company may need to start taking a back seat on performance.

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Comments

Very insightful article concerning the balance between safety and performance facing a sole-supplier series. Great to hear that Pirelli is choosing safety as being paramount in the equation. I might suggest that Michelin's MotoGP management read this article several times. 

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