VALENTINO Rossi once again suffered tyre problems during last Saturday's MotoGP race at Assen.
Rossi was lapping in 5th, closely followed by team mate Hayden, Pramac Ducati's Barbera and Tech 3 Yamaha's Crutchlow however, Rossi struggled and slipped back, eventually pitting mid-race to replace the rear tyre.
Rossi wasn't the only rider to suffer; Pramac Ducati's Barbera was affected and Yamaha's Ben Spies also struggled with tyre issues - possibly costing him a podium finish.
Both factory Ducatis of Rossi and Hayden struggled with tyres at Silverstone and the problem appeared to carry over to the first Free Practice at Assen, where both riders only managed to put in a couple of fast laps before rear tyre grip affected them. After Free Practice, Rossi said: "We need to modify the settings to improve the rear grip and have the rear tires sliding less, create less temperature and have better life for the second part of the race."
All riders opted for a Medium compound front tyre - the hardest available - while Rossi, Hayden, Barbera and Spies all opted for a Medium rear, Stoner and Pedrosa both ran a Medium-Soft. Interestingly, Dovizioso also ran a Medium, but managed a podium, while Lorenzo, who was taken out at the first corner, had also opted for a Medium, meaning he may have encountered the tyre issues his team mate Spies did.
The head of Bridgestone's Motorsport Tyre Development, Shinichi Yamashita, said: "Today saw the highest track temperatures of the Grand Prix weekend and the race was run at a very fast pace. The warm temperatures meant that all riders selected the harder front slick, while all but seven riders selected the harder slick option for the rear as well.
“Unfortunately a few riders experienced a problem with their rear tyre today and we sincerely apologise to those riders affected. We have commenced a full investigation into the matter and I will personally take the affected tyres back to Bridgestone’s Technical Centre in Japan tomorrow where they will undergo detailed analysis to determine the cause of this issue.”
