Bridgestone is to consider offering multi-compound tyres for next year's US Grand Prix, after a spate of accidents during last weekend's event at Laguna Seca.
Chris Vermeulen, Colin Edwards, Casey Stoner and Jorge Lorenzo were among those who suffered big highside accidents during the weekend, which they attributed to the right hand side of the tyre being too cold. Lowside falls were also common throughout all three days, but attributed more to rider error.
Tohru Ubukata, Bridgestone Motorsport's manager of Motorcycle Race Tyre Development, confirmed the tyre temperature problems, but also stated that corner characteristics played a significant part in the biggest falls.
“Tyres naturally generate peak grip when they are properly loaded, but in turns three and ten in particular it was harder for the riders to load their rear tyres because the corners are downhill, meaning the weight transfer is towards the front of the bike and away from the rear tyre, giving less rear grip,” he said,
“There are fewer right-handed corners at Laguna which meant that the right shoulder of each tyre was not used as much throughout the lap. The right shoulder also cooled between right-handers, especially as the ambient temperature was relatively low, so ensuring the tyres were properly up to temperature was crucial for the riders.
“Jorge [turn ten] and Casey [turn three] crashed during the qualifying session on their first quick laps out of the pits on new rear slicks. They didn't get enough temperature in their tyres before their attacking laps, as they explained in the post-qualifying press conference. This meant that their tyres were operating at a lower temperature, especially on the right side, and this was a major contributor to their falls,” he confirmed.
Whilst defending the decision to use single compound tyres at Laguna, Ubukata admitted that Bridgestone will consider the use of multi-compound rubber for next year's event.
“The temperature data we collected from last year's race allowed us to predict that the temperature differential between the left and right shoulders would be only a few degrees Celsius, and we based our tyre compound selection for the [US GP] weekend on this data,” he explained.
“This year's tyres are designed with a much wider temperature operating range than last year's so we chose to bring the single compound to Laguna because we believed they would be suitable for the conditions.
“Our temperature prediction was correct, and the difference between the shoulders of the rear tyres was very similar to that experienced in Mugello and Assen, where we also used single compound tyres.
“I support our tyre choice this weekend, but of course as part of our continual development process we will carefully analyse all our data from the weekend and consider asymmetric tyres for Laguna next year,” he concluded.
Bridgestone is expected to supply multi-compound tyres for the forthcoming German Grand Prix.