Roberts baffled by poor top speed

The American's best speed trap figure put him at 306.2 km/h on the main straight, well down compared to the fastest Honda of Dani Pedrosa at 317 km/h. The fastest machine was Casey Stoner's Ducati with 324.7 km/h.

Speaking about the figures, Roberts said he was struggling to understand just why there was so much difference between himself and other Honda riders.

"This morning I did 306 km/h on the straight this morning without any wind," he said. "I've always been down a bit (on top speed) but Hayden's been only two or three km/h ahead of me.

"I'm maybe not confident, but still, my first lap this morning was my fastest, and yesterday too, with my top speed."

He added: "I'm braking 30 metres deeper in qualifying, but my speed is still the same. I'm exiting the last corner at the same speed so I don't even draft on the straights. I don't see anyone."

Roberts said he had made no changes to his engine settings over the weekend.

"I haven't changed any ECU setting or anything like that. We just need acceleration more than anything else, so it's up to me tomorrow."

Roberts weighs about 16kgs more than Pedrosa, which could have an effect on the figures, but no more than Hayden.

Top Speeds of all Honda engined riders in qualifying today:

Pedrosa  317.0   315.7   315.0   315.0   314.9
Hayden   312.5   310.7   310.4   309.5   309.4
Elias    312.2   311.7   311.7   310.2   309.5
Nakano   312.2   311.6   310.3   309.7   308.8   
Checa    310.3   309.8   309.6   309.3   309.3
Melandri 308.5   308.0   306.9   306.9   306.6
Roberts  306.2   305.4   305.3   304.8   304.7
Stoner   324.7   323.0   322.9   322.8   322.5 (Ducati)