What’s up with Michelin’s MotoGP tyres? Part 2

MotoGP

There are plenty of rumours and conspiracy theories doing the rounds at the moment, so let’s take a deep dive in the Michelins

Michelin, 2021 Doha GP

Laser-checking a newly fitted rear slick in the Michelin fitting bay at Losail

Michelin

Last weekend I spoke to several experienced MotoGP engineers – who have worked with Bridgestone, Dunlop and Michelin – to find out what’s going on with Michelin’s MotoGP tyres. And I promised them anonymity, so they could speak 100% freely.

I had loads of questions. Why do riders need to save the tyres? Why does Michelin use reheated tyres? And what’s the deal with Michelin’s new asymmetric front, which proved so unpopular in Qatar?

Click here to read part 1

 

Why do riders need to save the tyres?

There is another aspect of the Michelins, specifically the rear, which can complicate races. Some compounds degrade fast enough to require riders to save the tyres during the race, by riding as smoothly as possible – how they use the throttle and how they manhandle the bike.

“At some tracks you can’t put the tyres into the corners aggressively, you can’t open the throttle aggressively, so you need to do everything silky smooth,” says Jack Miller. “The smoother I am the faster I go.”

Is this a bad thing? Not necessarily, it just introduces another element of skill into the racing equation. And saving tyres is nothing new – back in the 1980s and 1990s Wayne Rainey and others took care not to overcook their tyres.

Of course different bikes affect the tyres differently. Miller says the Michelin rear works better if he nurses the tyre towards full performance, but Suzuki says this isn’t an issue for its riders. Perhaps this is due to different engine characters – the aggression of the Desmosedici versus the smoothness of the GSX-RR.

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There are two other factors at play here.

Today’s fastest MotoGP bikes make around 300 horsepower – no tyre is going to survive 40 minutes of full gas from that kind of engine.

Michelin spec tyres were introduced alongside Magneti Marelli spec software, purposefully designed to be much less clever than the tailormade software developed by the factories during the previous decade or so. That factory kit automatically adjusted traction control, torque delivery and so on according to tyre wear and changing grip conditions, to help conserve the rear tyre.

The spec software does none of that, so it’s up to the rider to use his brain and his right wrist to do that job.

I’ve little doubt that the fans who complain about riders needing to look after the tyres are the same fans that complained about hi-tech factory software taking the skill out of riding.

And what about the theory that Michelin designs its tyres to degrade early to make the racing more exciting? It’s possible, but Michelin HATES the fact that it has yet to break every Bridgestone race record. After five seasons of Michelin MotoGP tyres seven race records are still held by Bridgestone: Aragon, Assen, Brno, COTA, Motegi, Phillip Island and Termas.

Michelin hopes that some of those records will go this year, because its 2021 range of tyres are slightly harder, for better race-long performance.

 

Why does Michelin use reheated tyres?

Pol Espargaró, 2021 Doha GP

Pol Espargaró and the other three Honda riders struggled with front tyres in Qatar

Honda

In Qatar there was much talk of the effect of reheated and reused tyres. Riders have been reheating and reusing tyres forever – because the only alternative is to throw them away before they’re finished, which would be madness.

So are reheated/reused tyres a problem in MotoGP?

“You get a small performance drop if a tyre is reheated from the previous day,” one crew chief told me. “But these tyres are still good enough to assess settings changes – electronics, suspension and so on – in testing and free practice.”

Reheated tyres are distributed evenly among riders and marked accordingly, so teams make sure they’re only used when the rider isn’t racing or chasing absolute lap times.

 

What about all the front-end crashes?

Michelin’s rear slick is better than its front slick, just as Bridgestone’s front slick was better than its rear slick. Therefore the vast majority of MotoGP crashes are caused by the rider losing the front in corner entry. In the Bridgestone spec era the most common accident was a corner-entry highside.

“I’d much prefer the situation where riders are losing the front, in which the rider is only falling half a metre and then the centrifugal force tends to carry the rider out of the danger area,” said another engineer. “During part of the Bridgestone era a lot of riders were getting highsided from the rear, which is never nice. In this sense the Michelins are definitely friendlier than the Bridgestones.”

 

Is spec-tyre racing a good or a bad thing?

Some fans pine for the days of open-tyre competition. The fact is that no system is perfect. There are positives and negatives to both.

The negative of spec tyres is that riders and factories must adjust their techniques and engineering to suit the tyres. But even old-school engineers like Jeremy Burgess preferred spec tyres, because they forced him to work on the bike, rather than band-aid a problem with a special tyre.

“With spec tyres it’s the same for everyone and whoever develops the bike to maximise tyre performance comes out on top,” said JB in 2009, MotoGP first year of spec tyres.

And then there were the overnight specials, designed to dovetail with data gathered on Friday, manufactured on Saturday and flown or driven to the circuit for race day. For favoured riders only.

And that wasn’t the worst of it. Back in the days of open tyre competition the companies had different grade tyres for different grade riders, so what chance did an up-and-coming rider have when he had lower-grade tyres?

2021 Doha GP Michelin

Fitting a front slick to a Repsol Honda rim at Losail

Michelin

World Superbike rider Chaz Davies tells a story from his 250 GP days that perfectly illustrates this problem.

“I remember visiting the Dunlop truck on a Thursday afternoon to have a look at my tyre list for the weekend,” says Davies. “My list was always really simple: a couple of different tyre numbers for the front and couple for the rear. That’s your lot. This time they gave me this tyre list which was more like a book: five different fronts, seven rears… I stared at it for a bit and then the Dunlop guys snatched it back off me.

“They’d shown me [Andrea] Dovizioso’s tyre sheet by mistake. That’s what you were up against – if you paid for the better bike you got better tyres too.”

 

What’s the deal with the new asymmetric front?

Asymmetric MotoGP tyres have been part of the game since the 1990s. Some circuits demand much more from one side of the tyre than the other, so it makes sense to use a harder compound on one side and softer rubber on the other.

Asymmetric fronts are a more recent innovation. Front tyres are more complicated, because the rider needs perfect feel from the front to attack corners and if the tyre slides there’s not much chance saving it, so it’s important that front tyres give no nasty surprises.

This year, Michelin is allocating more asymmetric fronts. The medium front in the Qatar/Doha GPs allocation was asymmetric, but it proved very unpopular. Over the two weekends only four riders chose the tyre for one race, the second Doha round, and they were the four KTM riders.

Many riders suffered crashes with the asymmetric, because then there was too big a difference between the softer rubber on the left and centre of the tyre and the hard rubber on the right.

KTM and Honda riders were the real victims, because the RC16 and RC213V are built to make time and make passes during braking and corner entry, so they need a tough front tyre. At Losail the RC16 and RC213V destroyed the soft tyre and couldn’t race with the hard tyre, which was only in the allocation for the much, much hotter daytime practice sessions.

Brad Binder, 2021 Doha GP

Binder risked the asymmetric front for race 2 in Qatar and reaped the reward

Red Bull

“Three-quarters of the tyre is the (softer) K compound and the last quarter on the right is the (harder) H compound,” explained LCR Honda rider Álex Márquez. “There is a lot of difference between the K and the H, so when you go into a right corner and move to the harder compound you lose the front. So your riding style needs to change a lot from lefts to rights, so this tyre isn’t nice to ride.”

Brad Binder also suffered several crashes with the asymmetric front. But after destroying the soft front before half-distance in the Qatar GP he decided to use the tyre for the Doha GP. His second race time was 13.7 seconds better than the first – an improvement of six tenths per lap – and he finished eighth, instead of 14th.

“The main difference between the two races was that the asymmetric front tyre lasted to the end, so I was able to push all through the race, whereas last Sunday, with nine laps to go, I was a passenger on the bike, just trying to get home.

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“I was really quite scared to go back onto the medium front, considering that I’d already crashed three times with it. But we didn’t have a choice. The soft wasn’t an option, because even doing two time attacks in qualifying on the same front tyre it was impossible to push. So it was clear that even though we didn’t like the medium we had to race it, because we wouldn’t see the end of the race otherwise.

“I just had to be super-careful going over from one rubber to the other. I had to brake almost straight and through the change gently – I couldn’t brake through the change, otherwise I’d have a front lock, which gives you a lot of negative feeling. I changed my style a bit in right-hand corner entries and once I’d figured that out I could push harder.”

This, of course, is one of the negatives of giving the same tyres to everyone. Some tyres inevitably suit one bike or rider better than others, but over the course of a season it’s swings and roundabouts.

And riders having to use tyres they don’t like for this reason or that is nothing new. In fact it happens all the time in every championship. Every rider wants to use the grippiest tyre, but more often than not they have to compromise. That’s the nature of racing.

However, it remains to be seen how Michelin’s asymmetric front works at other tracks.

“Michelin’s intention is perfect,” was one crew chief’s view of the Losail asymmetric front. “They’re trying to make a tyre that more riders can use, but at the moment it’s not working. Let’s hope it’s different in Europe…”