The Ducati factory’s situation at the start of the 2024 MotoGP season could be said to be very comfortable, even luxurious. Two factory machines complete with Pecco Bagnaia who is super consistently strong, plus two more factory machines in the hands of Pramac Racing with another sharp world champion candidate namely Jorge Martin plus four other 2023 World Champion motorbikes in the hands of four racers with good levels of performance and consistency . From previous years, it has been proven that the ‘old Desmosecici’ is still able to excel compared to competitors/other brands. . . However, when entering the second GP at Portimao, especially at CoTA 2024, the Red Alert came on!
The Desmosedici’s technological leadership has the potential to collapse especially if we refer exclusively to the Texas GP. NKOTB, ‘Bad Boy’ Pedro Acosta with Austrian technology and Maverick Vinales who was basically untouchable at the two Grands Prix of Portimao and CoTA, set off alarm bells that reverberated throughout Borgo Panigale. Even though Jorge Martin still leads the standings and there is still a chance of victory in the first two races, Aprilia and KTM currently have strong conditions and potential where they cannot be touched by Ducati. This is clearly a red alert in the early days of Mauro Grassilli’s leadership who replaced Paolo Ciabatti.
What we could see after the Texas series, problems hit Ducati from two sides, namely from the technical and non-technical sides. We are talking about technical matters, where it has been almost 10 years since TMCBlog has heard of a problem called chatter on the rear-end of MotoGP motorbikes and in 2024 it will suddenly return, especially to the Ducati squad, especially those using the Desmo GP24. Initially, TMCBlog thought it was due to Ducati reducing the dimensions of their salad box, which is generally the place where the Tuned-Mass Damper, which relieves chattering symptoms, resides, but it turns out that after chewing for longer, this is more of a ‘luxury problem’. .
Yes ‘Luxury Problem’ that’s what we call it. . Chatter/vibration is present on the Ducati GP24 and GP23 due to the increased level of grip on the Michelin rear tires they use in the 2024 season. “Grip is getting better, even chattering,” said Anggie Ang on the Trans7 MotoGP Podcast. “Excessive anything is not good.”
“I struggled all weekend on the soft tire – a lot of vibration at the rear. We put too much pressure on the rear tire and every lap it got worse. We have a lot of problems with chatter here and in Qatar – we have to solve them, or we will have these problems all season. Other brands don’t have it — I don’t understand why.” That’s what Jorge Martin complained.
Pecco Bagnaia’s chatter complaints after the Qatar Sprint: “I got a lot of chatter from the rear — vibrations after three or four laps”. And after the Grand Prix race in Portugal: “Today I had a chatter — we didn’t expect it.”
Excessive grip causes this chatter, which forces racers to slow down or risk falling, because the tires literally bounce on the asphalt of the track and make the racer feel like they are racing on a track with an asphalt surface shaped like a rolling board for washing clothes so that the tires can bounce when rides with a height of between half to 6 mm. The question is where does this additional grip come from? Judging from the syllogism, it is clear that Marc Marquez and other racers using GP23s will not experience chatter in 2024. So it is suspected that the cause is the 2024 Michelin slick tires.
Michelin in 2024 presents new front and rear tires in terms of compound solutions. Compared to Bridgestone which has a strong, grippy and consistent front tire, Michelin has long been known for its great rear tire grip, but when they returned to concentrate on the rear tire, this resulted in increased grip because the chemical compound of the rubber compound was changed. So the result is chatter because this time the vibrations felt by the tire rubber cannot be maximally dampened by the suspension and mass damper at the rear of the motorbike.
Öhlins MotoGP chief engineer – Mats Larsson – explained to Mat Oxley “The tire itself has a certain level of damping. The natural frequency (damping) of a tire is around 17Hz to 19Hz [17-19 cycles per second], so if there is any irregularity or imbalance on the motorcycle that corresponds to the same frequency then vibration will begin. It might only happen at certain speeds on certain corners and certain lean angles.”
What Mats Larsson means in basic physics is the concept of wave interference, where if two waves with the same frequency interfere (combine) then the result is an increase in the amplitude of the vibration.
An easy example is if a 1Hz wave with an amplitude of 1 cm meets a 1Hz wave with an amplitude of 2 cm, constructive interference will result in the form of a wave with an amplitude of 3 cm. Would it be scary if this happened on a motorbike?
