In this report, MotoGP’s official tire supplier looks back on Round 7 of the 2011 MotoGP World Championship, the Iveco TT Assen.
Ben Spies took his first MotoGP victory in fine style on Saturday at Assen, controlling the MotoGP race from the front to romp to an eventual 7.7 second lead over second-placed Casey Stoner and his Repsol Honda teammate Andrea Dovizioso.
The weather had been overcast all day and rain meant that the 125cc and Moto2 races were both wet, but by the start of the MotoGP race the conditions had become sufficiently dry for slick tyres, although the skies remained overcast.
In the cool and slippery conditions, every rider on the grid opted for the softer specification front and rear slicks apart from Marco Simoncelli (San Carlo Honda Gresini MotoGP) and Karel Abraham (Cardion AB Ducati MotoGP), who used the harder option front.
With the Assen track barely damp by the start of the race, the initial lap was always going to be crucial but several riders fell foul of the conditions. Abraham and Randy de Puniet retired in separate incidents, whilst Marco Simoncelli got caught out exiting turn five and took Jorge Lorenzo (Yamaha Factory Racing MotoGP) into the gravel with him although both rejoined the MotoGP race.
Hiroshi Yamada (Manager, Bridgestone Motorsport Department) says: “This is a fantastic win for Ben, especially during Yamaha’s 50th anniversary celebrations, so I’d like to congratulate his team and Yamaha for their performance today.
“He becomes the tenth rider to have taken a premier class win on Bridgestone tyres and it is good to have a new race winner in MotoGP. It was a very tricky weekend for riders but also for our tires.
“All season the temperature at races seems to be significantly lower than last year, and with the effect of rain over the last three days the track condition was very slippery and off-line it was still damp so today many riders used the softer slicks for improved warm-up.”
Hirohide Hamashima (Assistant to Director, Motorsport Tyre Development Division) says: “The conditions today were cold and damp in places which meant that almost all riders used the softer option front and rear slicks.
“The soft compound front was used for its improved warm-up performance and grip with the low temperature, but the compromise of this means that tyre wear was therefore higher. Some riders experienced some graining of the front tyre, including Cal who opted to return to the pits for a fresh soft front slick.
“Generally, as Ben showed, rear tire performance was okay today, even on the left side, although a few riders got caught out on the first lap. Andrea reported a vibration from the rear of his bike but investigation shows that this didn’t have anything to do with the rear tire but may have been the effect he felt of graining on the right side of the front tire.”