Italian GP: Williams team investigating Valtteri Bottas's start woe

Bottas dropped from third on the grid to 11th at the end of lap one after a poor getaway and early struggles with wheelspin.

Although the team initially believed that clutch problems were to blame, performance chief Rob Smedley said there was no firm answer yet.

"We're looking into it," he said. "At the moment it's not 100 per cent clear.

"Initially we thought it was a clutch problem, but then looking at the clutch delivery and the torque delivery on both cars they seem to have worked OK.

"He just seemed to have an awful lot of wheelspin.

"I think the grip was low and he couldn't feel a peak of grip and getting the tyres up to temperature and neither could Felipe [Massa].

"We'll just have to look at all the aspects of it and how Felipe was able to start better.

"Felipe himself said the grip was low and that he was having to manage it himself.

"We'll look at all the aspects: how they approach the starts and how they might be able to improve."

Bottas said his impression when the lights went out was that the clutch delivery was too aggressive, which gave him too much wheelspin.

"Compared to the grip I had available in the tyres I think we were too aggressive with the clutch," he said.

"The start for the formation lap, where we always do the final checks, was a bit compromised because Lewis [Hamilton] had a slow getaway - and that maybe hurt a little bit. But definitely the tyres were not in the optimum window.

"I had a poor start but the same thing continued after Turn 2 [Rettifilo exit]. It was just spinning until fifth gear."