Despite the introduction of a single tyre rule, the recent San Marino Grand Prix at Misano marked the sixth time this season that a MotoGP lap record has been broken.

The single tyre rule puts Bridgestone in a difficult position, where it must balance its competitive instincts to go faster against ensuring equality in terms of tyre supply to each rider on the grid.

The Japanese company seems to have got that balance right, although if lap records continue to be broken the company might soon be asked to reduce grip levels to help contain cornering speeds - a factor mentioned when the decision to end open tyre competition was made. Safety and cost were the two main reasons given for moving to a single tyre.

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"Of course I am very happy as it demonstrates the level of performance our tyres are delivering and the speed they are allowing the riders to ride at," replied Bridgestone's tyre development manager Tohru Ubukata, when asked about the broken lap records.

"We have no tyre competition in MotoGP anymore, but the fact that six new lap records have been set this season gives a good comparison of the level of performance of our tyres this year.

"This season, new lap records have been set by Valentino Rossi at Jerez, Assen and Misano, by Jorge Lorenzo at Brno and Indianapolis, and by Dani Pedrosa at Sachsenring.

"Jerez, Assen, Brno and Misano all have high average lap speeds and both Sachsenring and Indianapolis have abrasive surfaces, so I am very pleased with the performance of our tyres in these demanding conditions."

The only real disagreement between Bridgestone and the MotoGP riders so far this season has been over the issue of more asymmetric tyres.

This came to a head during the US Grand Prix at Laguna Seca, when a number of riders were caught out by the rarely used right-hand side of the symmetrical tyres supplied for the event.

Bridgestone agreed to consider the use of asymmetrical tyres at next year's US GP, although the fickle nature of which type to use, at which track, was illustrated by the recent back-to-back events at Indianapolis and Misano.

Asymmetric tyres were used at Indy, which has ten left- and six right-handed corners, but symmetric tyres were provided at Misano, which has six left- and ten right-handers!

"Even though Misano has six left- and ten right-handed corners, the opposite of Indianapolis, asymmetric tyres were not needed here because of the temperature differential between the right and left shoulders of the tyres," explained Ubukata.

"We only use asymmetric tyres when one side of the tyre is put under significantly more stress and load than the other and thus operates at a higher temperature, and at Misano the temperature differential is much smaller than it was in Indianapolis.

"Also, the layout of Misano means that there is a regular flow of right- and then left-handers, so each side of the tyre maintains operating temperature through the lap rather than cooling gradually between corners."

Ubukata then revealed that, of the four rounds remaining this year, asymmetric tyres will be used at three of them - Estoril, Phillip Island and Valencia - with only Sepang having symmetric.