Yamaha: 2006 bike best, despite chatter.

Valentino Rossi may have won Saturday's Qatar Grand Prix, but the chatter problems that struck so badly at Jerez were still present - albeit on a smaller scale - and Camel Yamaha spent Sunday's test day again trying to fully eliminate the vibration issue.

"It's always quite hard to get up early and go testing the morning after a victory, but (Sunday) was really important for us and the riders; the whole team has worked hard all day and made the most of the time we had available," said team director Davide Brivio. "In truth we still haven't completely solved our problem, but we've been able to gather a lot more important information and now we have to use this in the best possible way between now and Istanbul."

As part of the chatter solution search, Rossi - as at the last one-day test in Jerez - completed several of his 58 Sunday laps on the chatter-free 2005 YZR M1. No lap times were released for the '05 machine, but Rossi's best lap of the day was a 1min 56.25secs - good enough for second on the test timesheets, just 0.27secs behind Fortuna Honda's Marco Melandri.

However it was Rossi's team-mate Colin Edwards that suffered most at Qatar, qualifying eighth and finishing just ninth, but the Texan was buoyed by lapping just 0.1secs from Rossi during 66 test laps.

"We've definitely made some big improvements, for both riders," declared Brivio. "We've tried many different settings which have made the problem much less critical, allowing the riders to ride the bike at a better level. Valentino was obviously able to win and in the race the problems virtually disappeared, but we knew that they were still there and we managed to make some good steps forward. Colin had a difficult race and this test has been really important for him; he's finished the day in a much better situation."

On the subject of the 2005 M1 versus the new 2006 model, Brivio claimed that - although the 2005 machine has no chatter problems - the new bike is still better.

"Valentino once again tested the 2005 bike so we could make some comparisons. We know that with this bike the situation is different and we don't have vibration, but we also know that the 2006 bike is better in most other ways and has more potential," said the Italian. "We also tested a qualifying tyre today as this was when the problem was at its worst during the race weekend, so this was interesting also. Overall it's been a good day for us and hopefully Yamaha can use all this information to our advantage so that we are ready to fight with both riders at the front in Turkey."

The Turkish Grand Prix, round three of the 2006 world championship, takes place on April 30.