Valentino Rossi was at a loss to explain why the Yamaha riders struggled in Saturday's wet qualifying session for the German MotoGP.

The Italian could only manage ninth on the grid (+1.367s), but was still the second-best Yamaha behind Tech 3's Jonas Folger in fifth (+0.908s).

"Unfortunately in the wet I struggle," confirmed Rossi, winner last Sunday at Assen.

"It looks like all the Yamahas except Folger are a bit slower than the Ducatis and the Hondas. In qualifying it was very difficult and we tried a lot of different things but we were never strong enough."

While the 2016 Yamaha chassis has appeared far more effective in certain hot, low-grip conditions this season, the wet Sachsenring situation was even more confusing.

"We don't know what is happening and why the difference," Rossi said. "Zarco, with the 2016 bike, was last week on pole position [in the wet at Assen] and after one week in the same conditions he is in 19th place.

"I was strong in Assen in the wet and here I struggle more. It is very difficult to understand. Also compared to last year the feeling with the bike is totally different. Last year here in the wet I was one of the fastest. So...I don't know."

Team-mate Maverick Vinales, who lost the title lead at Assen, fared even worse and will start the race from eleventh: "When we touch the gas we lose so much. Our bike has no drive. The electronics are not working well."

Asked if he agreed with Vinales about the electronics, Rossi replied: "I don't know Maverick's problem, but in acceleration we lose. We have less traction and spin more on the exit of the corner."

Fortunately for The Doctor, he is looking more competitive in the dry. Rossi improved from 16th on Friday to 6th in FP3, despite another early technical issue (this time related to his fuel pump), before the afternoon rain.

"Today we improved a lot and in the dry I am not fantastic, but my pace is not so far from the top guys and I am quite competitive," he said.



Both wet and dry pace may be needed in the race, with weather forecasts predicting that the sunshine and showers will continue on Sunday.

"This weekend it looks like the weather is very crazy and changes all the time; anything can happen tomorrow," said Rossi. "Sincerely I hope for a dry race because I can be closer, but we have to work to modify things in the morning for both conditions and try to understand to be stronger."

Last year, Rossi dropped from the lead group to eighth due to a badly timed bike swap in the same kind of changeable conditions.

"I think tomorrow could see the same situation [as last year] because it looks like the weather could be very similar to today: rain and dry and the track drying very quick, maybe even more than last year.

"So we will try to be ready and I want to be strong in full wet and try something in warm-up but we have to be ready for all situation and react on the bike in the right moment."

Should riders need to change bikes, an added complication for Rossi and Vinales is that they have only one new chassis each.

"The problem for me is that I feel better with the new chassis both in the dry and the wet. I think we will start with the new chassis anyway...or maybe the opposite. For sure it is not the perfect situation, but it is like this."

Rossi goes into the grand prix third in the world championship, just seven points behind leader Andrea Dovizioso, who also faced issues in the wet and qualified down in tenth.

Sunday's race will be the first on the new Sachsenring asphalt, which offers high grip in the wet and is also quick drying.