Driving out of those famous red gates at Mugello on a warm, Sunday evening in early June, all was well in Maverick Vi?ales' world. A runner up spot at the Italian Grand Prix was not the result he had not come for, but in accepting his placing on the final lap, he had shown the maturity that is so essential in any championship charge.

An increased championship lead of 26 points was the reward, and with Valentino Rossi and Marc Marquez trailing by a considerable 30 and 37 points respectively, Vi?ales was already dealing with post-race questions relating to how he would nurse what was quickly becoming a sizeable advantage.

Since then however, the 22-year old's world championship bid has hit rough waters. Not only did Vi?ales have to contend with a frustration-filled run to tenth at his home grand prix at Montmel?. Yamaha's attempt to fix the '17 M1's diabolical performance in hot temperature/low grip conditions appears to have favoured his team-mate, not him.

The Iwata-factory brought two new chassis for Vi?ales and Rossi to evaluate at a two-day post-race test in Catalunya. And while the Italian veteran immediately talked up one of those new frames, Vi?ales was hesitant, and seemed less convinced. "It was better, but not in the way we expected," he stated enigmatically after trying one of the new designs on the Monday.

Assen would bring no reversal in his fortunes, as both he and Rossi had one new chassis, and one '17 frame, which Yamaha began the season with, apiece. Aside from leading FP2 and receiving the billing of clear pre-race favourite from Marc Marquez, Vi?ales' endured a disastrous qualifying performance in the wet.

The race wasn't much better. Although he showed the speed to, at the very least, challenge for the podium, Vi?ales crashed mid-way through the 26 laps, attempting to bridge a 3s gap to the leading group. "The strangest crash of my life," he later called it, appearing slightly baffled, before admitting he "was pushing myself over the limit" when his rear spun out and flung him off in the final chicane.

Intriguingly, the Catalan wore an expression of extreme dissatisfaction throughout his dealings with the media in the Netherlands - even on Friday, after dominating that afternoon's proceedings. Furthermore, he was guarded when speaking of which chassis he was using. "They [Yamaha] don't let me tell you, that's why I don't answer your question," he said. "If not, I would answer for sure."

Had he been angered by this shift in Rossi's fortunes, which included the famous 115th grand prix win on Sunday? Or was there frustration that Yamaha had catered to Rossi's requests, in spite of his own championship position? Pure speculation of course, but there was evidently something eating at him.

This certainly had the hallmarks of Rossi attempting to re-establish a kind of authority in development direction. It's worth noting Vi?ales isn't used to being anything other than a team's number one (the start of '15, when he was a class rookie, aside). Could this have caught Vi?ales off guard?

Rossi had aimed a few barbed comments in the way of his young team-mate too. Sensing the chance to stick the knife in after the Catalan nightmare, the Italian subtly went for the jugular at the post-race test: "Maverick doesn't have any history with Yamaha and he chose the '17 chassis because he think it's what a Yamaha is," he said. "But for me, because I know more the evolution of the bike, I think that that with the 2017 version we lost something."



True enough, Rossi's complaints from the second preseason test of the year included an inability to enter corners as quick as he'd like with the '17 frame. The new chassis has appeared to cure his discomfort. Even Marquez noticed a change in the Italian's ways when following his M1 at Assen.

"On Friday, riding behind Valentino, I realised he was using the new chassis," said Marquez. "On the entry of the corner they have gained something. In this area we used to make a difference." Saturday and Sunday's results backed that up too, and Rossi made a point of praising the new frame in the resulting post-race press conference.

And so, having contemplated the events at Assen for three-and-a-bit days, Vi?ales opened up a little further on the chassis, and the crash that led to his relinquishing of the championship lead for the first time since May in this turbulent 2017 campaign at the Sachsenring on Thursday.

Both he and Rossi will continue as they did at Assen, with one new chassis and one '17 frame apiece, they said. Vi?ales was honest too. "As I said, the new bike that we bring to Assen have a lot of potential but maybe it's not the best for my riding style because I'm used to being really aggressive," he said.

"The chassis I rode in the first part of the season gave me a bit more confidence to be aggressive on the bike, especially changing direction. It was really stable. Then quickly on the gas. That's what I feel more comfortable on. Anyway, the new bike, we have many areas that we can improve. We have to make the correct choice."

And, out of interest, why did he crash at Assen? Without saying which chassis he was using, his comments certainly hinted one way: "We analyse, but anyway it looks like I changed the direction too fast for the Yamaha with too much power," he said. "I was aggressive because I wanted to close fast the gap, because the laps were coming really fast.

"You know, I put too much gas. I went fast to the wheelie and then I quickly changed direction. The bike didn't have the correct balance to change direction. Honestly, it never happened to me, crashing in the chicane, especially in the exit."

So it appears Yamaha's two factory riders are favouring slightly different development directions - not a disastrous development by any means. The difference in both frames, after all, appears to be small.

"We are trying to combine all the positive things from both bikes, which is not easy because the advantage of this year's chassis is we have a lot of grip at the end of the races - the area we struggled last year," Wilco Zeelenberg told Peter McLaren at Assen . "Both chassis look the same, but the stiffness is different."

But, knowing elite athletes that refuse to believe there is anyone out there with a greater ability than their own, this weekend could take on greater significance. The Sachsenring is not just a chance for one to outscore the other in this tightest of tight championships. Ascertaining with some certainty which frame will lead them forward in this season's second half may well be open at this point. And, judging by both riders' recent comments, that could go some way to deciding their destinies come Valencia.