MotoGP testing: Yamaha races to catch up with new ‘IndyCar’ aero

This disease is caused by a mismatch between Michelin’s new-for-2024 compounds and some of the bikes, depending on tracks, conditions and possibly what the riders had for breakfast.

It’s also got a lot to do with speed. Lap and race records have been broken at every grand prix so far this year, because the new rubber gives more grip for longer, which can trigger chatter, due to the higher loads.

During the Jerez weekend I bumped into chief engineer Gigi Dall’Igna and popped him the chatter question. “Better,” he grinned. “But it’s not chatter, it’s vibration.”

Therefore my next stop had to be the Öhlins truck where the company’s new lead engineer Jonas Torstensson is based.

So, what’s the difference between chatter and vibration? (Bear in mind that most engineers have different opinions about these problems, which isn’t usual in pitlane.)

“I think it’s about semantics,” grins Torstensson. “Chatter is a type of vibration – it’s the tyre slipping, gripping, slipping, gripping, in a range of between 16 and 25 hertz [which means 16 to 25 chatter oscillations per second]. That’s tyre chatter and that’s what we usually refer to as chatter.

“Chatter can go up in the range, to 50 hertz or even 500 hertz. Then you can have lower frequency vibrations from the clutch, the drivetrain, the chassis, the engine, the crankshaft – maybe some unbalanced parts that resonate into the suspension, but that’s past what we call chatter.”

So this would seem to be Ducati’s problem. Could it reappear at super-grippy Le Mans next week? Possibly.

Aprilia chief engineer Romano Albesiano started out in the 1990s, working as a chassis engineer on Cagiva’s 500 GP bikes, so not many people know more about this strange phenomenon.

“It’s a super-complicated matter,” he says. “Generally there are two kinds of chatter that can be hard to cure.

“First, when you release the brakes into the corner, which can come from the front, or sometimes it can come from the rear to the front.

“Then there’s the vibration exiting corners, when riders apply the torque. There’s some deformation, particularly of the swingarm. As soon as riders get this vibration, they have to shut the throttle because the bike is sliding. Generally this occurs accelerating from slower, low-gear corners because the loads are higher.

“Every component of the motorcycle has a stiffness value – every structure has an elasticity, with its own frequency. From the tyres and the wheel rims up. For example, the seat structure is crucial, because it’s a long beam with a mass at the rear which can oscillate.”

“It’s very difficult to foresee the problem. Sometimes you go to a track where you have huge chatter problems, so the next time you go there, you say, ‘My god, what’s going to happen?’, and nothing happens.”

Riders play a part, of course. At the earlier races, Bagnaia and Jorge Martin suffered more than Márquez and Enea Bastianini.

“Marc and I have similar styles – I push a lot with the front on entry and don’t use the rear so much,” says Bastianini, who finished fifth on Sunday. “Pecco and Jorge push a lot with the rear and they are so aggressive on the edge of the tyre. I think this is their problem.”

Okay, enough of chatter. What about the stuff we can actually see?

Honda had its first major redesign of 2024 at Jerez. Test rider Stefan Bradl raced the latest RC213V (he finished 16th on Sunday), then LCR riders Johann Zarco and Takaaki Nakagami tried the bike in the tests. Factory riders Luca Marini and Joan Mir didn’t bother – they’d already ridden the upgrade in private tests and weren’t impressed. And neither were Zarco and Nakagami.

This lab bike features a revised chassis, new aero, with the design centred around huge diffusers at the lower fairing’s front, and probably much more besides, but all to no avail. Turning and grip are still Honda’s biggest handicaps. Back to the drawing board.

Yamaha’s first big redesign didn’t appear until Monday: a revised chassis, new aero and rewritten electronics for the YZR-M1

Yamaha’s major concern is turning, so much so that Quartararo’s riding technique is getting more and more radical – he hangs off so far to force the bike to turn that sometimes his outside boot can’t reach the footpeg, so he can’t control grip by loading the ’peg, which isn’t ideal.

Arguably, turning has been MotoGP’s biggest development focus of recent years, with chassis stiffness and downforce aero constantly evolving to make the bike grip better and turn better, because the sooner you can get the bike turned around the apex the sooner you can open the throttle.

Yamaha is now developing its aero with renowned Italian race-car manufacturer Dallara, which builds everything from IndyCar to Le Mans cars and also works in aerospace. Meanwhile Aprilia and Ducati have taken aerodynamicists from Ferrari, while KTM works with Red Bull Advanced Technologies, the engineering arm of the Red Bull Formula 1 team.

The M1’s new aero features a huge triple-element front wing, not unlike Aprilia’s double-element wing, plus side vanes, an idea nicked from KTM, which has had its RC16 fairings similarly equipped since last November’s post-season tests at Valencia.

The vanes create positive pressure above and lower pressure below, which sucks the bike into the ground, delivering more grip and better turning.

These upgrades didn’t propel Quartararo and team-mate Álex Rins up the timesheets – both finished the test outside the top dozen – but Rins did like the aero. Both will be back at work at a private test at Mugello before next week’s French GP, but don’t expect to see the new kit used in anger until the Catalan or Italian rounds.

If you think that Honda’s and Yamaha’s lack of immediate progress is a bad sign, you may be right, or you may be wrong. There are no immediate fixes in MotoGP anymore. Way back in 1992, Honda changed the game in 500cc GP racing by introducing its so-called big-bang engine configuration. Cagiva, Suzuki and Yamaha were left floundering in the new NSR500’s wake, but within a few months they’d built their own big-bang engines and were back in the hunt.

That kind of fix isn’t possible now. Modern MotoGP bikes are many, many times more complicated and multi-faceted than the 500s, and every single part of the motorcycle must work in unison with the others.

It took Ducati five winless seasons and multiple redesigns to get back in the hunt with Honda and Yamaha, and there’s no reason to believe it will be any different for the Japanese now.