Valentino Rossi struggled with rear grip on his Ducati as he finished outside the top 10 in 11th place on the opening day of the Malaysian MotoGP.
Rossi had hoped to experiment with several tweaks to the balance of his Desmosedici in the afternoon session in an effort to increase rear grip, but a heavy downpour before the start of FP2 threw a spanner in the works.
The Italian superstar will now start afresh on Saturday after finishing 1.6s behind pacesetter Dani Pedrosa in the dry FP1 session in the morning at Sepang.
“We've been a little unfortunate with the weather in recent races,” Rossi said.
“This afternoon it rained right before the session, which made it difficult to work. It's a shame, as we had two or three things to try with the balance of the bike after we were pretty slow this morning.
“We had continued working with some changes that we had used at Motegi, where they'd helped us to have a little more grip under acceleration,” he added.
“Here, though, they weren't as effective because they cause a lot of understeer.”
Rossi ventured onto the circuit in the mixed conditions in the afternoon, but it was ultimately a fruitless exercise.
“This afternoon it was important to be able to work because we wanted to return to a more standard set-up, like at Aragon and Misano,” he said.
“I tried riding a little in an effort to understand as much as possible, but it's difficult in these conditions.
“There's nothing we can do about it, so we'll have to wait until tomorrow.”