MotoMatters.com | Kropotkin Thinks

While Maverick Viñales and Marc Márquez emerged from the Sepang tests as clear favorites, with Valentino Rossi, Dani Pedrosa, and Andrea Dovizioso close behind, Andrea Iannone established himself as a genuine dark horse. The Italian was fastest on Tuesday, and left the test as second quickest behind Viñales.

Iannone has inherited a bike that is already well developed, and Suzuki brought engine upgrades to Sepang which got them even closer to the front. It was telling that Iannone did not spend much time testing parts, but rather focusing on race set up and working on extracting maximum performance from a used tire.

Tires were a bit of a problem for Iannone on the last day of the test. He crashed three times, including once as he was attempting a long run, the front washing out at Turn 1. The issue proved to be a vibration in low speed corners. "I have a small vibration in the slow corners," Iannone said. "In the fast corner the bike is perfect. There is no vibration, no chattering. But in the slow corner, especially in turns four, nine, 14 and the last corner, we have a small vibration at maximum lean angle." That vibration got worse as the tires became more worn.

Needle in a haystack

Was it a faulty tire? Michelin boss Nicolas Goubert said that the French tire maker would be examining all of the tires after the test to check for problems. But preventing vibrations in tires is complex. The tires are balanced on laser balancing machines after they have been fitted to wheels to ensure they are as perfectly balanced as possible. They are then given to the teams, who roll them away and put them in tire warmers, ready to be used.

From that point, a multitude of factors may change the behavior of the tires and wheels. Temperature variations due to imperfect tire warmers can slightly alter the shape of the tires. Small knocks while the wheel is fitted in the bike may cause a minor imbalance in the tire or wheel. Brake discs and hubs can wear unevenly, causing a vibration. Suspension can have a huge impact on tire wear and bike behavior. Pinning down a vibration to a single cause is notoriously difficult. That is both convenient for Michelin and a pain. Teams can point at Michelin, and Michelin can point at teams, and it is impossible to tell who is right.

Rins and repeat

Iannone's teammate Alex Rins had a very good test at Sepang. He had started slowly on Monday, looking to build his confidence after the massive crash he had at Valencia, his first outing on the MotoGP bike. He quickly got his speed back, cutting 1.8 seconds off his lap time between Monday and Wednesday, more than any other rider present. He ended the test in twelfth, just a fraction behind his teammate, and ahead of established riders such as Danilo Petrucci, Jack Miller, Hector Barbera and Scott Redding.

But Rins was not the most impressive rookie. That, in the opinion of almost everyone present, was Johann Zarco. Zarco had spent Tuesday morning riding on wet tires on a drying track, trying to get to deepen his understanding of where the limits lay on a MotoGP bike. He improved his time by nearly 1.5 seconds over the three days, and showed good consistency.

Rookie rampage

Valentino Rossi had told the media he had been impressed by both Monster Tech 3 Yamaha riders. "Zarco made a very good job," he commented afterwards. "Also Folger was fast. I followed him, and he rode very well." Zarco – a sensitive soul, serious and intense – was deeply touched by Rossi's words. He had gone racing after watching Rossi on TV, so to be complimented by his idol was something that left him moved.

Jonas Folger may have been slower than his teammate, but the German had also made good progress. He had not improved his times much – just 0.3 from Monday to Wednesday – but that was more a function of how quick he was on Monday, rather than how slow he was on Wednesday. Folger had clearly benefited a lot from the test he had at Sepang in November.

Last of the rookies, Sam Lowes, has perhaps the hardest row to hoe. Lowes, like Rins and Zarco, also had to regain his confidence after a big crash at the end of last year, and had a lot of adapting to do to the Aprilia. The RS-GP has made big strides forward, but still lacks horsepower compared to the other bikes. Lowes had improved his time by 1.6 seconds over three days, only Alex Rins and Bradley Smith having improved their times more. He ended the test 1.2 seconds behind his teammate, but looking forward to Phillip Island for a track that would allow him to understand the bike better.

Aleix Espargaro was pleased with the progress Aprilia had made, but still had one real complaint about horsepower. He was not using any traction control, he said, because the bike was not powerful enough to need it. The chassis was good, the bike turned, but he was simply suffering in acceleration. More horsepower is needed to fix this. And as I wrote on Monday, Espargaro has already tested a special aerodynamic package in a wind tunnel in Italy. That "very strange fairing" as he described it, will make an appearance at a later test.

KTM's workload

The younger Espargaro has a lot more work to do. The KTMs ended the test just under two seconds off the best time of Viñales, but that is closer than Suzuki ended in their first Sepang test when they returned to MotoGP. Both Pol Espargaro and Bradley Smith had been impressed by the work which KTM had done, but also overwhelmed by the amount of material they had to test, and the scale of the work ahead of them. The potential of the bike was very high, and they still had a lot of work to do to get it there.

Standing track side, it was clear how much work was left to do. The KTM RC16 was clearly a handful, the bike moving around under braking and on acceleration out of corners. I asked Pol Espargaro whether the bike was physical to ride. "Yeah, so much," he replied. "It’s really different than the bikes that we are used to riding. It’s physically demanding."

That was taking its toll physically. "It needs to be ridden wild," Espargaro added. "But even like that you get really tired. Even though the bike is wild the electronics and things make the movements of the bike even bigger. You have to hold it with the body. This is so physical."

The upside of that is that the KTM rewards a physical approach. "For sure the KTM is a bike that, when you push more, the lap time comes. You can make a crazy lap and the lap time comes." The problem is that maintaining that level of physical intensity was hard. "Making consecutive laps is really difficult. That’s what we were trying today – not just to make one lap, but trying to repeat with a used tire. This is the most important point right now. We can make one good lap but after this the bike becomes too aggressive and too nervous. We are trying and I’m happy. We’ve made big, big steps."

KTM had brought a stack of parts for Espargaro and Smith to get through, in reality, too much to do at one test. But they were fairly settled on their choice of chassis, with Smith preferring it a little more than Espargaro did. They also had swing arms to test, but that was not the priority. For both Espargaro and Smith, getting the bike to turn was the biggest challenge the KTM faced. Once that was working, they could focus on rear grip and drive.

Tires test too

It wasn't just the factories who had brought new parts to test. Michelin also had some new front tires for the teams to try, two with a different construction, and two with a different compound. The construction was aimed at providing better warm up, and the compound at improving the grip. The tires were generally well-received, though the difference they made was rather small.

That, in itself, is telling. The biggest difference Michelin had made came at Valencia last year, when they brought a front tire with a new profile. That had created a larger contact patch on the edge of the tire, and provide better grip. That profile will form the base for Michelin's tires in 2017.

The fact that there were so few crashes was a sign the new Michelin front was working. The tire is good enough, and the riders and teams have the balance of the bike dialed in well enough to be able to understand where the limit is well enough to avoid crashing.

There were a few riders who fell, but the only serious faller was Tito Rabat, who crashed very heavily on Tuesday in mixed conditions, a huge highside in which he broke bones in his foot and hand, and opened up a nasty wound on his knee. Rabat has already undergone surgery to fix the problems, but he is likely to miss out on the next test at Phillip Island.

Gathering the background information for long articles such as these is an expensive and time-consuming operation. If you enjoyed this article, please consider supporting MotoMatters.com. You can help by either taking out a subscription, buying the beautiful MotoMatters.com 2017 racing calendar, by making a donation, or by contributing via our GoFundMe page.