Tires have always played a crucial role in winning the MotoGP title and nothing has more of an effect on a racing bike than a tire change... Which will be favored by the new rear slick from Michelin and who will encounter problems in the battle for the 2020 MotoGP World Championship?
This goes without saying – anything a motorcycle can do is no good if the tires can't transfer the power to the ground: there's no point having more power than everyone else if your rear tire isn't adapted.
Michelin's new rear slick for the 2020 season has a different construction that deforms to increase the size of the contact patch, and with more rubber in contact on the track, this increases grip.
But it's not that simple. Increasing rear grip changes the front/rear traction balance, which can create unfortunate side effects such as cornering issues and impact other performance factors.
If you increase rear grip, riders will use that extra grip, which puts more load into the rear tire. Logically, this reduces the load on the front tire, which reduces grip at the front, so the tire will wiggle on the asphalt, rather than sticking to the track to allow the rider to follow its line. Do you see the problem?
“The carcass of the new rear tire works better, so the tire becomes flatter, which increases the contact patch, so the bike doesn't want to turn,” according to an engineer at one of MotoGP's V4 factories. “The rider must physically force the motorcycle to turn. That's why Ducati was complaining about the tire, because they couldn't turn the bike, so they couldn't exit the corners properly. »
As for the engineers of the teams whose bikes are four-cylinder in-line, their feedback is more positive: “The new rear gives us more cornering grip so the rider can grip better in the corners and it also improves stability and traction when exiting corners, so the rider can use more exit speed and go around sooner.”
In other words, it appears that the extra force required to turn a V4 through corners causes the new rear tire to crush too much, shifting too much load to the rear and therefore penalizing cornering ability.
Even comments from Michelin MotoGP boss Piero Taramasso would seem to suggest that the tire might work better for riders equipped with inline-4 machines, which require less physical effort when cornering.
“With this tire it seems that drivers cannot be as aggressive as before,” explains Taramasso.
Factories like Suzuki and Yamaha would therefore be favored, while KTM, Ducati and Honda would seem worse off.
Jack Miller at Sepang in February – more rear grip helps braking but not necessarily cornering
Maybe, maybe not, because the first time the drivers and engineers were able to concentrate 100% on the new rear was at the Sepang and Losail tests in February, so they didn't have to only six days of complete testing with this tire.
The crucial factor in the fight for this year's MotoGP Championship will be which factories rebalance their prototypes for this new tire most quickly. This is something they will try to achieve during a hectic schedule of 13 races over 18 weekends, with no testing.
The engineers' goal will be to adjust the traction balance via geometry and suspension setup to shift weight forward, to increase front load and thus regain grip and cornering performance. Each factory will have to find its own setting. It will then be up to the driver to adapt his driving technique as early as possible to make the most of the advantages of the tire and circumvent all the negative points.
“The tire is more stable in corners and has a good advantage in the acceleration zone,” adds Taramasso. “Plus, it helps stop the motorcycle when the rider uses the rear tire to brake. Drivers will therefore have to brake and accelerate differently. »
No one knows who will get who will be favored by Michelin's new rear slick, but it's usually the smarter, more talented riders who figure out how to get the most out of a new tire or other technical improvement by adapting their technique management according to their needs.
The first two rounds of the championship – at Jerez at the end of July – will not conclusively show who the winners or losers will be with the new Michelin – the situation could change from race to race as the different teams and factories will understand the secrets of the tire and will adapt to them.
