Maverick Vinales hopes Suzuki's new MotoGP frame will help end the "nightmare" of struggling when temperatures increase.
While Suzuki has made significant progress in its second season back in MotoGP, Vinales and team-mate Aleix Espargaro have both called for more rear grip, to help prolong tyre life, especially in races and warmer conditions.
Last weekend at Barcelona, Vinales set the pace in Saturday morning's third practice session, but several hours later in a hotter qualifying session could only manage sixth, 0.740 seconds off pole.
"It's starting to be like a nightmare," he said after the session.
"I'm moving a lot, no grip on the rear, it's difficult to stop.
"I really don't know what to do to improve on that because it's nearly one year, the same, the temperature was high I cannot make the same laptime.
"This morning I made the same laptime, going fast, but not on the limit."
The 21-year-old, who is moving to Yamaha next year to replace Jorge Lorenzo, finished fourth in Sunday's race, but nearly 25 seconds behind his future team-mate and race winner, Valentino Rossi.
"When the bike has grip, like [Saturday] in the morning, on the first laps on the new tyre I can do incredible things," he said.
"But then when the grip went down, I started to struggle a lot on the bike, especially with the electronics, then it starts to move a lot.
"Always it's the same, when the grip goes down a little bit the tyre lasts 10, 11 laps, we start to struggle, the bike starts to move."
Suzuki did not use the new 'B' specification of its frame during the grand prix weekend, but Vinales could race with it at Assen.
Following an initial test at Valencia last month, Vinales' programme during Monday's post-race Barcelona session focused on the new alternate frame, along with various electronics settings.
"I really feel more confident with it," he said.
"For the race weekend in Catalunya we decided to go back to the standard frame as it was too risky to go with the new one, but with the work we've done, and the new settings we tried, the improvement is significant.
"Compared to [Sunday's] pace I could improve a lot, but also the general feeling is better, as it allows me to ride with more confidence.
"My request was to have more rear grip, and Suzuki worked to modify the chassis in order to be more efficient in this area.
"Now I feel more confident in the middle part of corners and this allows me to be less aggressive on the tyres."