Just as he had predicted after a disappointing sixth place in Sunday's Misano MotoGP, Maverick Vinales was back on form in the high grip conditions at Tuesday's official test.

"Nobody can give me an explanation. It's quite frustrating that I can practice so well, then when the race arrives the bike is not working," Vinales had said. "Now we have a test, more of the same; super grip for the test, everything works well, and then in the races I have the same problem."

Vinales tried a range of new parts - including a chassis, rear finger brake and swingarm – on Tuesday, rising from seventh in the morning session to fastest of all by the end of the afternoon.

"I‘m still a bit disappointed about what happened on Sunday, because also today we were strong," Vinales said. "Even after [a crash], I immediately did a fast lap afterwards, I was able to ride a 1‘31-medium.

"I rode that best lap time with the new parts, and it feels like it can maybe help me gain something for the race. Already last week the bike was really good, and it‘s difficult to improve it.

"With the new part I can ride the same lap times, but much more relaxed. This is a positive sign. It means that if I need to push, maybe I can ride a little bit faster."

The only rider to chose the hard rear tyre for the race, which Rossi felt was a major factor in the Spaniard's race day woes, Vinales now believes he's ready to run the medium or even soft rear this weekend.

"During this test we solved the problem with the graining that I had with the medium tyre, so for sure we will try to ride more with the medium tyre this weekend, but also the soft worked really well. I could do many laps and I finished the session with some 1‘32-low laps, which is really good for us," Vinales said.

"We just need to understand why I lose grip during the race and feel like I‘m riding on ice, because if that‘s fixed, I can ride very fast and hit really good lap times without being on the limit."

While the Sunday grip-loss remains Vinales' Achilles' heel, Rossi's top priority at the test was to 'find some extra top-end speed and improve rideability'.

The main development to try and cut Yamaha's engine deficit, which seems to have grown following the discovery of valve faults at Jerez, was a huge new exhaust.

Petronas star Fabio Quartararo didn’t think it made any performance difference and soon took it off, while Rossi – who also tried other unspecified new parts - was less clear.

"We did a lot of hard work today, I did many laps, because we had a lot of different stuff to try," said the Italian, who rode for a massive 90 laps and was 17th fastest, 1.4s behind Vinales.

"The test was not so bad. We worked on the bike. As always, out of all the things we tried, some were an improvement, others weren‘t. But overall it was a good test.

"We found something that was positive, so we will try to be stronger for the upcoming weekend."

Exactly what Rossi found isn't yet known, but team director Massimo Meregalli revealed the new chassis will not be seen again this season.

"We had a long list of components to try here, including the chassis, rear swingarm, muffler, finger rear brake, and some setting tweaks," Meregalli said. "The new chassis didn‘t bring to the table what we expected, and we decided to use the current chassis for the remainder of the season.

"We will use the next few days to study today‘s data. If we confirm the riders‘ feelings in the data, Maverick and Valentino will already start FP1 with some of the other new items that we tried today.

"We also used this test to try a tyre combination that we might consider for the next race – hard front, medium rear – that unfortunately we weren‘t able to try last weekend."