Factory Ducati stars Nicky Hayden and Valentino Rossi were left in search of traction in the searing Catalunya heat on Friday.
The pair had made an encouraging start to the fifth round by lapping 0.471s (Hayden) and 0.762s (Rossi) from the top in morning practice, but as the heat increased so did the traction problems.
Hayden finished ninth in the afternoon session (+0.958s) with Rossi dropping to twelfth and last of the manufacturer bikes, but having stuck with the harder option rear tyre.
“This morning was pretty encouraging. The position wasn't great, but 0.471 from the top is about as close as we've been in a while,” admitted Hayden.
“The track temperature was really hot this afternoon, and we struggled a bit getting traction, especially in the long corners that Barcelona is notorious for. If the conditions are the same on Sunday, tyre life could be more critical than we've seen in some time.”
Following a private test at Mugello, Rossi was riding with the new aluminium swing-arm and electronics package. Hayden also has the electronics, but is sticking with the carbon fibre swing-arm after chatter issues with the aluminium.
“The things we tried from the Mugello test definitely helped a bit, and we still have plenty of ideas to try tomorrow,” said Hayden.
Rossi seems to be suffering from the same grip issues as his team-mate
“Today obviously didn't go great, but it wasn't as bad as it seems because when everyone put on the soft tyre at the end, I preferred to continue working for the race and kept the hard,” he began.
“Sure, we still have to improve the set-up because we're having a hard time with acceleration. We can't find enough grip, and none of the changes we've tried so far have worked.
“This track is always very difficult when it comes to rear traction, but anyway, the other riders were faster, so we also must improve. Tomorrow morning's session will be very important for trying for a good qualifying position in the afternoon.”
Last year's Catalan Grand Prix marked Rossi's most competitive showing on a Ducati, in terms of distance to victory. The Italian crossed the line in fifth place, 7.4s from race winner Casey Stoner (Honda).