The first day back after the winter break is always tricky. Bodies are sore after riding a MotoGP bike for the first time. That uses muscles which are impossible to train, and so soreness quickly sets in. Then there are the unforeseen hiccups which always arise when prototype machinery first hits the track. Parts don't quite work as expected, they don't fit as easily and as quickly as hoped, and there is always a nasty surprise lurking somewhere. But then again, that's why you go testing, to iron out the details before racing starts in earnest.

Andrea Dovizioso was just one of many riders hindered by such hiccups. "The first day you have to try a few things and a few things can happen which make you lose time," the Italian said. "You can't follow exactly the plan. That's what happened today. It didn't work a lot but we had to fix a few small problems – nothing bad."

Or it can rain. As it did for an hour in the afternoon, and then again shortly before the end of the test. With the track taking time to dry, that meant the riders lost probably two and a half hours of track time on Friday. But all of these things are just a part of testing, and something everyone has to deal with.

Older is better

So perhaps it is unsurprising that the two fastest riders at the end of the first day were the two Petronas Yamaha riders who didn't have much to test on Friday. Fabio Quartararo topped the timesheets on the 2019 Yamaha M1 – actually an updated bike with a bit more power – as he has to wait to get one of the limited number of 2020-spec machines Yamaha has. On the first day, Valentino Rossi and Maverick Viñales had two new bikes each, plus one of the updated 2019 bikes, while the test team had two 2020 bikes in the garage.

On Saturday, Yamaha will take one of the 2020 bikes and place it in Quartararo's garage, so he can start the process of working for the new season. "It was the plan to ride the 2019," the Frenchman said, "but of course now I'm looking at my phone every hour to try the new one and have the first time the feeling of the new one!"

Both the new 2020 bike and the updated 2019 bike have been given more horsepower. But the 2020 bike is still just at the start of its development cycle, making it difficult to judge. "It looks like we are a bit faster in the straight, but it's a little bit too early to say because we don't understand very well," Valentino Rossi said. "It looks like the gap is less but for sure we have to work."

Fast by the right yardstick

Yamaha's philosophy means that there will always probably be a gap in top speed to the fastest bikes. There always has been in the past. It is not the fact that a gap exists which is the problem, but the size of the gap. If Maverick Viñales, Valentino Rossi, Fabio Quartararo, or Franco Morbidelli can hang with their rivals in the slipstream, they can use their ability to get the bike stopped to get ahead on corner entry. And if they can enter the corner ahead, they can use better corner speed and better exit drive to pull a big enough gap through the corners that outright horsepower can't easily close. The aim of Yamaha is not to build a bike with the highest top speed. The aim is to build the fastest bike on the grid. And that is measured in lap times, not through speed traps.

Another focus is not losing speed when grip drops. This is where Yamaha has suffered most: when there is lots of grip, the Yamaha is probably the quickest bike on the grid. But when the grip goes away, as it does when a track is hot and greasy, or cold, damp, and slippery, the speed of the Yamaha goes up in smoke.

This is where the Honda and Ducati have been strongest. The Honda, especially, couldn't match the Yamaha when grip was high. But when grip went away, as it so often did when the afternoon sun beat down on a track covered in Dunlop rubber laid down by Moto2, the performance of the Honda and the Ducati stayed relatively stable, dropping only a bit, while the Yamahas suffered a lot.

That makes Sepang a very useful place to test for Yamaha, believes Maverick Viñales. "It's always so difficult in the test here. If you take the first two hours, and the last 30 minutes, those are the good minutes on the track. The rest is very hot, very slippery, but for us, it's very good to test in these conditions. The more slippery it is, the better it is for us to test."

Mixing it up

The fact that there were three Yamahas in the top six was certainly promising for the Japanese factory. But the fact that all six MotoGP manufacturers were in the top eight was even more intriguing. Alex Rins on the Suzuki was just a quarter of a second behind Quartararo. Cal Crutchlow on the LCR Honda and Jack Miller on the Pramac Ducati GP20 were a few hundredths slower than the Suzuki, and the Espargaro brothers, Aleix on the Aprilia RS-GP, and Pol on the KTM RC16, were five and six tenths behind the Petronas Yamaha. It is only the first day of the test, but the field seems to be closing up.

Ducati did not get too deep into their testing list, Andrea Dovizioso said, as they were bogged down by small technical details. That was what the first day of testing was for, to get those out of the way before knuckling down to work. We will know much more about where Ducati stand by the end of the weekend.

Suzuki was relatively busy, with Alex Rins focusing on a new aerodynamic package, while Joan Mir worked on the engine, tested a new chassis and swingarm, and worked on his body position on the bike. "The chassis looks like it's working," Mir said, "but we have to try some different settings with it because at the moment it's really new, and to understand it, we need more laps." Worryingly for Suzuki's rivals, Mir felt that the chassis helped the bike turn better. "It looks like the chassis turns good. Only small differences. It's not a huge change, but you can feel and it can makes a difference for sure."

The new, new bike

At Aprilia, testing is strictly rationed by the number of bikes available. There are currently only two 2020 RS-GPs in existence, with very limited spares. So Aleix Espargaro is doing the bulk of the work to refine the rough diamond the new bike promises to be.

Espargaro was clear about the comparison with the old bike. "Definitely much better," the Spaniard said. "It is difficult to compare because it is early in every single area. The best thing I will say is the turning. When you release the front brake the bike turns a lot more and the position of the rider is also much better. The new engine character is also a lot easier to ride. Super electric but we are still missing quite a lot of acceleration, but overall to be here on the first day I am satisfied. I think this bike has a lot more potential."

How early is it in the life of the RS-GP? Aprilia don't want to let Espargaro try a long run, because they are not sure the engine would survive such a severe stress test. The new bike has a huge amount of potential, but there is still a long path ahead.

Tortoise and the hare

KTM were continuing the work of the shakedown test, working on the new chassis and refining the engine. They are going slowly and methodically, however, preferring to chase real progress, rather than try to rush things. "We prefer to go slowly with new parts and putting everything together," Pol Espargaro told us. "It's a safer way to improve the package. We have done quite well and our pace is close to last year's fast lap here, so we are much, much better than last year, and in the shakedown we improved the KTM record here by around 3 tenths. So it feels good and we are more competitive than ever here in Malaysia, in a place we always suffer a lot."

Espargaro once again praised the work of Dani Pedrosa in helping to pick up the testing load, and define a direction for the bike. He was also grateful for Miguel Oliveira in the Tech 3 team, and the fact that he was no longer a rookie, and could provide useful input, despite the fact that Oliveira is just back from shoulder surgery. He already had more help than he had had the previous year, Espargaro said.

Honda was limited by the fact that two of their riders were fresh off shoulder surgery, and a third is a rookie. Yet there was work to do, though as usual with HRC, they were very close-lipped about what exactly they were doing.

The weight on his shoulders

For Marc Márquez, his first priority was understanding how his shoulder was holding up. There was good news and bad news on that front: the right shoulder was less painful than his left shoulder had been last year, but it was also weaker. "Compared to last year I had more pain but more power," Márquez said. "This year I have less pain but less power. I expected this already before coming here because one of the muscles that is more important in the shoulder is still not in perfect condition and I already expected this before riding the bike."

Even though Márquez had undergone very similar surgery on the opposite (left) shoulder last year, it was still difficult to tell how his body would react and recover this time, the reigning champion said. "The thing is you never know about the body," he said. "About my body's general feeling, I feel better than last year. The problem is that muscle takes time to activate. Just two weeks ago it was impossible to ride a bike. Then it started to activate a bit and that's the reason I'm here today. But I need to have patience. We will see."

He was working incredibly hard on his recovery, he explained. "Yesterday my physio said to me 10 weeks, 92 sessions, 250 hours. It's not a joke. Not a lie. It was from the 2nd of December, double sessions per day." That effort was something that team manager Alberto Puig had warned him about. "When we took the decision to have the surgery, the first question of Alberto to me was 'Are you ready?'" Márquez told us. "I said, 'Yeah.' He said, 'No, are you ready on the mental side? Because two winters doing four hours every day from the morning to the night is hard.'" But, Márquez added, that is part of the job. If you want to win, you have to put in the hard yards when things are against you.

It had restricted the amount he could spend on track, Márquez said. "Today the plan was to be in this range of 30-35 laps. Tomorrow we will try for 45. Then the next day we will see." But at least he could start work on preparing for the 2020 season. "The most important thing is I feel not so bad on the bike. We can try the things and concept things to try and find a good base for the first race."

Better rubber

One thing that most of the riders tested was the new Michelin rear. That tire, which has a different construction, allowing the use of slightly softer rubber, has a little more support and a little better grip. But that had a big change on the bikes.

"It's still not clear," the ever-cerebral Andrea Dovizioso replied when asked about the new Michelin. "I have some feeling. In the middle of the corners it slides a lot, the rear tire. In the traction area the grip is good. I think the lap time is faster because the grip is a bit more. But the way you have to ride is different. This means the setup has to be different. Still we didn’t have time to work on that. Also the electronics have to be set up a bit different."

Dovizioso was also uncertain how well the new rear tire would behave in the race. "It seems good about that but it’s impossible to simulate this at the test," the Ducati rider said. "First because unfortunately the tests are always less and less so you don’t have a lot of time to do a lot of work. You have to try some material because during the weekend it’s not good to do. It’s difficult to have time to make a lot of laps and understand the tires. It’s very difficult to ride in exactly the same way as the race. The rear consumption we will know in the race."

Maverick Viñales certainly felt that the new rear provided more grip. "In Valencia and Jerez, it had a lot of grip, but here it's different," the Monster Energy Yamaha rider said. "Also I didn't try the soft, so I don't really know the potential of the soft tire. But the idea is to keep going like that, especially in slippery conditions, which you find at most of the tracks. But I feel good traction, which is always very important for our bike."

Marc Márquez felt the new rear would be a big help during qualifying, and the last 10 minutes of each free practice session, which has become a kind of de facto pre-qualifying. "The new rear tire is much different," he said. "There is better grip, especially for the time attack, you can be very fast and push a lot the tire. It will be interesting and also difficult to understand this grip. This I think will benefit some riders to make the time attack. But for race distance the way the tire drops is more or less in the same way but more grip all the time. The time attack is one thing but this tire is much better for the race distance too. Also you need to adjust and adapt the set-up of the bike."

We will know more tomorrow, as work continues. Saturday, at least, looks like offering a full day of riding. There is a lot of work to do, and not much time to do it in.

Times at the end of the first day of the 2020 Sepang MotoGP test.

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