Marlboro Ducati's Valentino Rossi noticed a small improvement in front-end grip with the new aluminium chassis on his Desmosedici MotoGP bike in first practice this morning but problems with tyres and a lack of track time have prevented much detailed analysis.

The Doctor did one run on the carbon-framed bike in the opening session and then switched to the new chassis. He said that even with rear grip problems caused by a too-soft tyres he was getting less understeer and more stability, and would see how the new bike stacked up in the extended session tomorrow.

The first impression (of the frame) like in Mugello we improve the agility of the bike and the change of direction where we were very slow, there is remaining some understeering but the front feeling is not so bad. The distance from Dani remain huge but we are not so far from Dovi and Simoncelli," said the nine-time champion, speaking to bikesportnews.com this evening.

"This morning the feeling was not so bad, I use mainly the new bike after the first run but the bigger problem here is the rear grip because first the tyre on the left is a bit too soft for this temperature and we are struggling too much with it so we have to do some adjustment in the setting like spring and preload for to understand.

"With this lack of rear grip it is difficult to understand exactly the feeling with the front. The first impression was not so bad so I have to try better this afternoon but this afternoon is cancelled so I have to try tomorrow morning.

"One long practice is worse than two short practice, especially for work on the bike but we can understand better tomorrow and continue with aluminium frame and see our potential. Sure, it's nothing special this morning but the feeling is not so bad. It's just a small improvement, I don't expect to see 0.8 on the other bikes."