PICTURES: Rossi rides 2008 prototype.

Rossi, whose 13th place in Sunday's wet/dry Japanese Grand Prix handed Casey Stoner the crown three rounds early, evaluated two chassis designs for next year's M1, although he continued to use the existing engine.

"Today we made the very first test with the first prototype of next year's M1," confirmed the Italian superstar. "It is not a completely new bike, because the engine is the same as we used in the race, but we tested two different chassis. We used the same engine as yesterday in order to be able to better judge any improvement.

"One chassis was stiffer than the other and with the stiffer one I felt some vibration, but with the intermediate one my feeling was really very good," he revealed. "Of course this is the first step, but with that in mind it was a pretty good test. Now we must work on the engine for next year. After the last race in Valencia we will test the chassis again, and also a different engine, so I look forward to seeing it there."

"Today we have tried two different chassis, in order to give indications to the engineers about which way must take the development of the 2008 bike," confirmed team director Davide Brivio. "One of them seems to work better than the current [2007] one and might be a good option to use in the future. I think that today we were able to give a lot of valuable information to our engineers."

Rossi set the fourth fastest time at the test, 0.3secs behind Suzuki's Chris Vermeulen, and was also able to determine exactly what caused the chronic front tyre problems after his pit stop, which ultimately ended his championship chances.

"It seems that the problem was the temperature; when I re-entered the track after the change the pit-lane was still wet and the temperature of the front tyre dropped drastically," said Rossi who, fearing a technical problem, pitted again at the end of that lap. "That's why Colin and I could not ride the bike in the very first laps; we both had the same problem. Now we go to Australia and I am confident we will be competitive there and that we can finish the championship in the best possible way."

Sharing the track with just six other riders, team-mate Colin Edwards put in the second fastest lap time, 0.053secs behind Vermeulen.

"Today was a pretty good day after what happened yesterday," said the Texan, who finished 14th in the race. "We tested a new front tyre that I am really happy with and a couple of different rears. I think Michelin brought some good new material here and it's been encouraging to have the chance to try it out with the last three races in mind. We were so focused on the tyres today that we didn't touch the bike at all. It seems that the stuff we tried was pretty good, so I am much more confident for the next races. Now we go to Australia and the Yamaha seems to always work good there, so I look forward to getting on board again at one of my favourite tracks and getting some results."

"We are now ready to move on to Phillip Island in good shape, put this result behind us and be competitive again," concluded Brivio.

There is now a two-week break before MotoGP heads to Phillip Island for the Australian Grand Prix.