Yamaha chase grip with 2010 YZR-M1

Valentino Rossi’s crew chief Jerry Burgess reckons Yamaha has achieved one of its major 2010 targets by improving rear grip with a new YZR-M1 chassis.

As well as increasing performance and durability with its in-line four-cylinder engine, a key target for Yamaha was to give nine-times world champion Rossi more grip from the controlled Bridgestone rear tyre.

And Aussie Burgess reckons Yamaha has made big strides after Rossi recently topped the timesheets at the opening winter test session in Sepang earlier this month.

He told MCN: “We tried to improve rear grip. Bridgestone has to bring a tyre that suits everybody on the grid, whether it be for Gabor Talmacsi last year at the back or Valentino and Casey (Stoner) at the front.

“Don’t get me wrong, that tyre is a very good tyre. But there are two or three riders who would probably choose something a bit stronger if they had the chance.

“But we don’t have that chance and we’re not complaining about that.

“It is up to us to maximise the grip we get from that tyre for longer because we’re perhaps putting more stress on that tyre than other riders on the grid.

“It’s just a way of making a setting on our bike that optimises the performance of the tyres we have.

“We’ve changed geometry and rigidity with the chassis because obviously you want to get a bit more traction.

“The options to do that are with more weight on the rear and different stiffness in swingarms and chassis.

“From the outset when we ran the bike in Brno and Valencia last year it was positive. But if you have a gain in the rear you’re losing something in the front.

“You’ve obviously got to make sure the loss and the turning isn’t compromised too much. It is a bit of a juggling act.”

Burgess and Rossi will be back in action when winter testing resumes in Sepang on February 25.