Rossi explains exhaust, swingarm change

Valentino Rossi has explained his decision to revert back to the standard Yamaha exhaust and swingarm at this weekend's Japanese MotoGP.

The Italian was the only M1 rider to race with the factory's new double exhaust and carbon fibre swingarm for the past two rounds.

But Rossi is now unsure if they offer an advantage and, in order to try and solve his rear grip problems, has decided to eliminate some of the technical differences compared to the other Yamahas.

"In the last two races I have a lot of problems with rear grip and I suffer more than the other Yamahas," Rossi said.

"So for me, especially about the [new] exhaust, we are not ready because it looks like it's not at the same level as the standard exhaust.

"We need more time [to work on it] but unfortunately in a race weekend you cannot do nothing, you are always trying for performance. So we will see during this winter.

"About the carbon swingarm, for me there is not a difference. It's not worse, but we decided to go like the others and we'll see.

"[Friday] was not so bad, my pace was quite good, we have to work also because the tyre choice is open. Maybe tomorrow we will try also if we are strong in the wet!"

The forecast rain arrived on Saturday morning, although Rossi's fifth place on the dry Friday timesheets means he is assured of a place in Qualifying 2.

Petronas Yamaha rookie Fabio Quartararo and Rossi's team-mate Maverick Vinales were first and second on Friday.

Vinales has tried the exhaust and carbon fibre swingarm to gather data in testing and practice, but always switched back to the standard parts for the race.