Williams Formula 1 team admits it must conquer soft tyre

Felipe Massa and Valtteri Bottas finished fifth and sixth for Williams in last weekend's Chinese Grand Prix, unable to keep pace with race winner Lewis Hamilton, his Mercedes team-mate Nico Rosberg or the two Ferraris.

While both Mercedes and Ferrari ran Pirelli's soft option for a second successive stint in the race, Williams was unable to do so because its data showed it could not make the compound last long enough.

As a result, Williams was forced to use the slower medium tyre for the longer middle stint, which is where Massa and Bottas lost most of the time.

"The standout point was that the two teams in front of us in the championship were able to run the option in the second stint," said Smedley.

"If you look at our degradation towards the end of the first stint, it was high enough to ward us off that tyre.

"We have to go away and look at the philosophy of our weekend and understand why we couldn't run the option."

Bottas said Williams also struggled on the medium prime tyre and could do so again in Bahrain, where the softs and mediums will be in use.

"We struggled with the prime tyre overheating because the working range for the prime tyre is quite low," said Bottas.

"Even when we tried everything to reduce the temperatures for the race, for the tyres it was not enough. We need to improve on that.

"With the mediums we will still struggle if we don't find anything in one week but it's another different type of track and I think last year we weren't too bad."

But Smedley said all teams were struggling on that compound.

"I think overheating the medium is a bit of a feature of that tyre," he said.

"If you look at our pace towards the end of the race with Ferrari when we were both on primes, it was actually more similar.

"So I don't think we are overheating that medium any worse than anybody else."