Britain's Cal Crutchlow is still concerned with the problems he suffers stopping his Monster Yamaha in the early stages of MotoGP races despite finding a slightly better setup in Barcelona testing.

The Isle of Man resident, who rejected a frame upgrade after testing it in Spain, has difficulty stopping the YZR-M1 with a full tank of fuel as does Valentino Rossi and the pair are mystified as to why Jorge Lorenzo doesn't have the same trouble.

Crutchlow says it is not a fundamental problem with the bike but adjusting the setup to stop it will more than likely affect the bike's performance in the middle and later stages of a race, which he does not want to compromise.

"The bike is really good, I'm pleased with it so we need to adjust the setup but that is easier said than done. We could do that but then in the middle of the race or the end of the race it is worse so and at the moment, I have no problems there, it is the start of the race," said Crutchlow, speaking at Assen.

"I don't want to alter things that will make it worse in other areas. It is a real fine line. I can see Valentino's data and we ride very similar. If we alter the bike for the start of the race in the end it is worse. We can't understand why Lorenzo has no problem.

"Valentino's bike looks very similar to mine. When I see it on the television or see him riding, it looks similar and it is difficult to understand why.

"The factory team had the problem last year. If you look at the pace for the first five laps of the races this year, we have been as fast as the factory team went last year. I'm not going slower but everyone is going faster.

"For sure we are still struggling to stop at the beginning of the race but you can get away with it more in the cold conditions, it seems, than in the warm. We want to be able to improve it in the warmer conditions.