Valentino Rossi took advantage of a new seamless shift gearbox on his Movistar Yamaha YZF-M1 to finish top at the Sepang 2 test after day 1.

Weather wise it was a difficult day for the teams with the track temperature approaching 60 degrees at times leading to a lack of grip which meant it was impossible for any rider to post a time comparable to the previous test here at the Malaysian circuit. In fact Rossi’s best lap of 2’00.414 was a whopping 1.5 seconds slower than Marquez’s fastest lap from Sepang 1, and over a second slower than his own best time from the same test.With all the fastest times set in the morning, most riders did not venture out on track during the peak of the daytime heat, instead waiting for the track to cool.

Then, just when the temperature was starting to improve, and with most riders heading back out onto the track, a torrential downpour put an end to any meaningful lap times and effectively brought an early end to the days action with 90 minutes to go. It did however allow some of the braver riders to head out and get some “wet” data for their engineers, before a massive thunderstorm caused the red flag to come out halting the session temporarily, before the circuit was reopened with only 20  minutes left.

Movistar Yamaha had a new seamless shift gearbox to put through its paces, although they would not confirm if it worked on both up and down shifts yet, simply saying it was an “evolution” of the gearbox they had used in the previous test. Whatever they did, it appeared to work, as Rossi finished the day 0.129 ahead of the Repsol Honda of Dani Pedrosa.

Both Repsol Honda riders spent Sepang 1 choosing which bike they wanted to develop during this test, but it was Pedrosa who adapted best to the tricky conditions to finish 2nd, over half a second faster than his teammate Marquez.

Pol Espargaro was 0.462s behind Rossi on the first of the Yamaha Tech 3’s after fine tuning the YZF-M1’s electronics package today, and 0.179s ahead of his brother Aleix Espargaro, who put in an incredible performance on his Team Suzuki GSX-RR to end up in 4th with a 2’.01.055.

After the last test in Sepang, Suzuki went back to Japan and spent extensive time in the wind tunnel developing a new fairing and also some engine updates to try and coax more power from the GSX-RR, an effort that was clearly paying off. Espargaro’s rookie team mate Maverick Viñales showed how quickly he was adapting to the premier class by setting the 9th fastest time of the day, with a lap just 0.9s down on Rossi.

It was a frustrating day for two of the title favourites as Jorge Lorenzo, even with his new gearbox, could only post a lap 7 tenths off the leading pace. Despite this, Lin Jarvis and the Yamaha team will still be happy as he was quicker than the current World Champion Marc Marquez, who could only manage a best of 2’01.190 which was only good enough for 6th place.

Cal Crutchlow showed signs that he was starting to get to grips with the more aggressive riding style he says is needed on the CWM-LCR Honda RC213V, with the Brit managing to post the  7th fastest lap of the day, only 8 tenths off the top spot. Bradley Smith continued his recovery from injury to finish just two hundredths behind Crutchlow on the Monster Yamaha Tech 3 YZF-M1 in 8th.

Ducati finally unveiled the much anticipated GP15 here at Sepang, a bike which they hope will get them back challenging for the title. It is smaller than the GP14.3 they rode here last month, and they have changed the engine position to try and improve the bikes well known problem with understeer. With Dovizioso and Iannone both riding the new bike back to back with the old bike to allow their teams to collect data, they were not focusing on lap times but still managed to take 10th and 15th respectively, and will be encouraged by the start they have made with there new machine which is the first to have its design completely overseen by team boss Luigi Dall’Igna.

Scott Redding will be pleased with his days work, finishing 11th after adapting his riding style to get the most out of the Estrella Galicia 0,0 Marc VDS Racing Honda, just over a second slower than Rossi.

It was a mixed day for the Aprilia Racing Team Gresini with Alvaro Bautista finishing in a promising 12th just 1.3 seconds off the leaders, but his team mate Marco Melandri just could not get going and ended the day last in 27th place.

Elsewhere Hector Barbera was the top Open class rider on his Avintia Ducati in 13th, while Jack Miller is still struggling to get used to his CWM LCR  Honda RC213V-RS and could not get under the 2’03 mark, leaving him in 22nd place.

For the full results head here.