Massa's Chinese GP practice tyre blows due to Williams set-up error

Massa first lost his left rear out of the fast Turn 5 right-hander early in the session, spinning across the gravel as he braked for the next corner.

He rejoined after repairs, only for the tyre to go down again almost immediately.

This time he was able to keep the car under control and return to the pits without drama, where an issue with wheel rim clearance on the tyre was diagnosed and rectified.

Asked by Autosport what caused the problem, Williams technical chief Pat Symonds replied: "Something on the way we'd set up the car caused the wheel failure.

"So once we'd realised what it was, we were able to alter that and it was fine in the afternoon.

"We did a lot of laps in the afternoon with no problems, so we're happy."

Massa admitted that losing most of the morning made it a "not very positive" Friday, but said he had no concerns for the rest of the weekend.

"If you don't exactly know the problem it has an effect because you don't know if the tyre will blow or not," he said.

"But when the team understands the problem, that's the important thing. I trust them."

Although only Massa experienced the deflations on-track, the same problem was evident on team-mate Valtteri Bottas's car.

Massa suspected Bottas benefited from the red flag to clear up his debris, and the Finn agreed that he had probably been "just more lucky".

Bottas is also confident the issue, which Massa underlined was triggered by a set-up modification rather than a new type of wheel rim, is now behind Williams.

"I had a chat with the engineers between the sessions and they explained in detail what they found and I felt confident going in the car," he asid.

"If something happens, then it happens. There's no point fearing ahead of it."