Bridgestone review Qatar challenge

Article from http://www.motogp.com/en/news/2011/Bridgestone+review+Qatar+GP

The opening round of the 2011 MotoGP World Championship in Qatar saw the MotoGP class’s official tyre supplier Bridgestone provide medium and extra hard front and medium and hard rear compounds to the premier class riders.
Run at night time and taking place in the desert, the Losail International Circuit provides a unique setting, one which places very particular demands on tyres with wind blowing sand onto the track. Here, Director of Motorsport Tyre Development at Bridgestone Mr Hirohide Hamashima reviews the four-day GP.
The race was run three weeks earlier this year than in 2010. Did this make any difference from a tyre perspective?
“Conditions this year were certainly cooler with track and ambient temperatures about seven degrees Celsius lower. This caused the track to be a little slippery, especially coupled with the dirty surface early on in the weekend, but we still used the same tyre compounds as last year with no problems. The operating range of our tyres is more than sufficient to deal with a change of ten degrees Celsius in track temperature. The lap times were fast too, especially during the qualifying session.”
How big a role did sand on the circuit play throughout the weekend?
“We experienced quite high winds for most of the week until the Saturday of the Grand Prix which left the track quite sandy, especially for the first free practice sessions. As more laps were completed it got cleaner, but during free practice one and two in particular we experienced some graining of the softer option rear tyre because of the sand. Graining occurs as the rear tyre loses traction and starts spinning, so this gives us an indication of how slippery it was at first. Nevertheless, this is one of the unique challenges of the Losail circuit so from past experience it was expected.”
The pace in qualifying was very fast – how was tyre performance in general?
“Overall I am satisfied with tyre performance this weekend. To lap within 0.2s of the outright pole position record, set on qualifying tyres in 2008, using race tyres is very impressive. Throughout the weekend the extra hard front tyre was the preferred option as it provides more stability under braking and is more durable, although some riders did use the softer option and had no problems with it. In the rear, the harder option was the favourite throughout the weekend because of its added durability and resistance to graining, though on the softer option in qualifying the times were very fast indeed which shows the level of grip it was producing once the circuit had cleaned was very high.”
“During the race durability was good. Casey and Jorge were able to lap within 0.6s of their respective fastest times until the end of the race and Andrea set his best on the final lap, which is a strong sign of tyre performance right until the end. We have confidence in the consistent and high quality of our tyres from last year to this and I am happy that the teams do too as this allows them to make good set-ups based on last year’s data. A good rider, bike and tyre package is very important to get the most out of our tyres.”