World Superbike Championship tyre supplier Pirelli has identified ‘excessive stress’ and an extremely hot track temperature as the reason for the failures riders experiences during the Misano round.
Yamaha’s Michael van der Mark was thrown from his YZF-R1 while leading the opening race of the weekend when his rear standard SC0 tyre failed. Later inspection by Pirelli revealed the carcass of the tyre had a hole in it.
The Dutchman suffered another tyre issue on Sunday, as did championship leader Jonathan Rea, while Jordi Torres was forced to retire out of second when he encountered a slow puncture.
Baffled by the spate of failures, Pirelli launched an immediate investigation into the issue. The Italian company found that the problems were the result of ‘excessive stress’ on the tyre brought about by the increased level of performance of World Superbikes in 2017.
Pirelli also revealed the high track temperatures experienced at Misano over the weekend played a factor.
Pirelli boss Giorgio Barbier urged teams to stick to the company’s recommended minimum tyre pressures, and feels Pirelli are being held back from properly monitoring its rubber by the fact not every team runs tyre pressure sensors.
“I believe it’s really evident to everyone that over the last few years Pirelli has been significantly increasing the level of performance of the tyres used in the Superbike World Championship,” he said.
“Which, it is good to remind, are standard products regularly purchasable on the market and not prototypes, like the ones used in MotoGP.
“With time, the power and the technological level of the bikes has also clearly increased compared to the past.
“The more the level of the tyre’s performances increased, the more the product’s ‘sensitivity’ to the smallest of external variables, such as pressures, increases.
“After what happened in the last two rounds we have decided to carry out an additional step for our product’s development, and we will continue to do so because we want to match the excellent performance with maximum reliability, which has always been a characteristic of our tyres.
“We should also mention the fact that the product’s development hasn’t progressed at the same speed as Pirelli’s possibility to monitor its tyres during the race.
“In other championships the tyre manufacturer is able to know, in real time, the pressure as each bike is equipped with pressure sensors.
“For us, this kind of control is currently impossible as not every team has pressure sensors.
“The pressures, together with a correct utilisation of the tyre warmers, play a very important role in allowing tyres with an extremely high technological level to work properly.
At Donington Park three weeks prior, Kawasaki’s Rea suffered a similar tyre failure to van der Mark. Rea’s exit was blamed on a cut found on his developmental SC0 tyre, and Pirelli could find no link between the issues seen at the British circuit and at Misano.
To combat any more potential failures, Pirelli will bring two development SC0 tyres with them to Laguna Seca this weekend, both of which featuring a stiffer construction previously used by the company.
