Have Suzuki, Yamaha found a season-defining advantage?

There are certain inevitabilities to life: death, taxes, Guns N' Roses being labelled as heavy metal (they categorically are not), and tyres being a dominant talking point of rider debriefs during MotoGP pre-season testing.

Predictably, this was the case at the recent Sepang test, in which the field further got to grips (pun semi-intended) with Michelin's 2020-spec tyres they will race in the upcoming campaign.

Michelin's new construction rear tyre is aimed at increased performance and improving durability, while also creating a more gradual drop-off during races. First tested last July in Barcelona, it was then trialled at the post-race Brno test and at a two-day Misano in-season test in August before being given 20 minutes of running at the tyre-punishing Phillip Island during FP1 in October's Australian Grand Prix race weekend.

As a result, there was no shock to the system for the riders when they took to Sepang last week. The performance of the tyre was not in doubt. On the combined times, 17 riders managed to lap within the 1m58s bracket - the fastest effort a 1m58.349s - while the top 19 were split by just 0.755 seconds - though test timesheets, as described by one rider, are often "fake".

But certain traits of the tyre hinted towards an advantage already being held by Yamaha and Suzuki, with a number of riders and paddock personnel concurring with that theory. The new rubber offers better edge grip when the bike is at increased lean angles as the contact patch is larger - and that plays into the hands of the grid's only in-line four cylinder-engined motorcycles.

The Yamaha M1 and Suzuki GSX-RR are famed for their superior cornering ability - see Maverick Vinales' devastating display at last year's Malaysian Grand Prix, or Alex Rins' charge to victory at the seemingly made-for-Suzuki Silverstone as examples of this. Since the contact patch on the edge of the tyre is larger, these bikes can punch out of the corners more adeptly - which gives it a slight edge under acceleration relative to the powerful Hondas and Ducatis.

Commenting on the rubber, Petronas SRT Yamaha rider Franco Morbidelli noted that it "fills our 'emptiness' of grip that we had last year". When asked by Autosport about Morbidelli's assessment, Vinales added: "A little bit, yes, but that is why we have to understand the tyres and how to work on the track.

Michelin has an almost impossible task each year. It has to supply tyres that work for all, but naturally whatever it does will benefit some more than others

"The guys in the team work very hard to understand, when we did the long run, [the bike has] a good set-up for me but not yet perfect. We're working well. I am happy we didn't go for one lap because the main focus was to work on the race pace."

Vinales ended the test down in 16th on the combined times, but put in an impressive long run on the final day - as did Rins, who was third on the combined times, 0.101s off the pacesetting Yamaha of Fabio Quartararo.

Michelin boss Piero Taramasso (below) doesn't believe the new tyre benefits the inline-four bikes by design; it's just that Yamaha and Suzuki have been able to find a set-up to suit quicker than the others.

"If you look at the performance of each other, it may seem that way," Taramasso told Autosport.

"It is true that both Yamaha and Suzuki have been very fast, but for this they have had to change the set-up, because with more grip back you must adjust the balance. It seems that with few changes they have quickly found a good set-up."

But even with this said, one of the intended traits of the tyre - to last to around lap "15 or 16 at full capacity" - will play into Yamaha's hands perhaps more than the rest. Tyre life has been an issue for Yamaha ever since Michelin took over from Bridgestone as sole rubber supplier in 2016.

It managed to somewhat improve on this last year, but Yamaha riders still tended to suffer pretty quick drops in pace with around 10 laps of a race to run. Combine improved acceleration - another key weakness of the M1 of late - from its redesigned engine and the better drive grip of the new tyre with the extended life that the new rubber offers and it seems Yamaha has clearly been the biggest beneficiary from the construction change.

Michelin has an almost impossible task each year. It has to supply tyres that work for all, but naturally whatever it does will benefit some more than others.

After two high-profile failures at the Sepang test for Loris Baz and in Argentina for Scott Redding in 2016 - the two heaviest riders on the grid and both on Ducatis - a much stiffer construction was introduced as a safety measure. This negatively impacted the bite-sized Dani Pedrosa who, at 51kg, regularly struggled to get heat into his rear tyre and extract peak performance out of it.

A front tyre construction change to a stiffer design around the 2017 Italian GP ultimately played into Ducati and Andrea Dovizioso's hands as he won the next two races and took the title down to the wire in Valencia. Mercifully, a mid-season change - outside of reasons of safety - won't happen again owing to a ban on that coming into force last year.

But that perpetual yin and yang of motorsport persists with Michelin's 2020 tyres, with Ducati and Honda looking to have been hit the hardest by the change.

Though LCR's Cal Crutchlow was second overall, he doesn't think the extra grip of the tyre is helping the 2020 Honda's corner-entry much, which is already a problem point due to the motor's aggressive engine braking.

Add to that the prevailing - and by Crutchlow's assessment even worse - turning issues of the RC213V, the added grip won't be helping in this area either as its riders can't spin the rear tyre as much to compensate for its front end and get the rear turned.

With just three days of testing remaining before the Qatar season opener in March, Honda and Ducati could be in for an opening run of races of damage limitation

Dovizioso doesn't feel the new tyre offers Ducati "a lot of grip" in the turns, and notes that the grippier rear is pushing the front more on the way into the corners. Dovizioso also says he can't drive out of the turns like he used to do, but believes there is still margin to improve the situation.

Ducati general manager Gigi Dall'Igna offered some relief to Dovizioso, suggesting that the Italian marque "did not have the ideal configuration for those conditions and those tyres" at Sepang. Crutchlow echoes this on Honda's troubles with the tyre, adding that his LCR team simply needs time to find the right set-up for the new rubber, while the riders will just get on with the task at hand.

But with just three days of testing remaining before the Qatar season opener in March, and with very limited time during race weekends to try radical set-up overhauls, Honda and Ducati could be in for an opening run of races dedicated to damage limitation.

Should Suzuki and Yamaha still hold the advantage they currently enjoy with the new rubber by the time the field reaches Qatar, it is imperative they capitalise on this to immediately to build a solid foundation for their long-awaited title tilts.