Eddie on Tire Pressure: Background Problem / MotoGP

The tire pressure sensors on the MotoGP are imprecise and can be tampered with, so factories don’t accept penalties if someone is caught non-inflated – like Bagnaia. Analysis by Ing. Rise.

Pecco Bagnaia, a factory Ducati rider, drove all 25 laps of the race with illegally low tire pressures during his victory at Jerez, and it became apparent this week. Allowable tire pressures also dropped in the case of factory Pramac Ducati rider Jorge Martin, who fell on the first lap and remained without a point. During 24 of 25 laps of the race. Alex Rins and Andrea Dovizioso also violated tire pressure regulations at the Spanish Grand Prix. But there are no penalties because the situation is complicated.

Since the 2016 Mugello GP, the MotoGP World Championship has required sensors on the rear and front wheels to monitor tire pressure. Since 2016, the minimum tire pressure for front wheel patches has been 1.9 bar and for rear wheel patches 1.7 bar. On Moto2, 1.5 bars are allowed in the rear. But the values ​​specified are not reliable, which is why the six MotoGP manufacturers decided not to accept the penalties.

This agreement has been in place for some time. Two of the most famous sensor manufacturers are LDL and McLaren.

The engineers of the six MotoGP manufacturers work in great secrecy on this subject. Because of course it is annoying and embarrassing that the details of this secret agreement have now been leaked to the public.

Meanwhile, desperate attempts are being made to find the location of the leak. No doubt it could have been Honda (only sixth place in the Manufacturers Championship and thus a disappointment) or Aprilia (Ducati’s archrival, Gigi Dall’Igna who left there in October 2013). Ducati, Yamaha and Suzuki were barely there as they stayed below the legal minimums in Jerez and wouldn’t tire themselves out.

Anyway, at one point Race Direction expressed a desire to introduce some tire pressure lower limits in the MotoGP class, to monitor and penalize misdemeanours. In the worst case, disqualification from the race was threatened, which is what happened to Fabio Quartararo in Moto2 in Japan 2018.

This intention was submitted to MSMA at the time, but all the manufacturers cried and fought back. “Because the borders are so narrow, the tolerances are very large and counterfeiting is very easy,” one technician explained to us. “Once there is pressure on the regulations on this topic, manufacturers are likely to start incorporating something and changing the values. Then nobody has more of it. One can then talk about tampering. Or you can say: I’m just using a different calibration. “.

Example: Some pressure sensors work in absolute terms, some work in relative terms.

What you measure with a manual pressure gauge is the relative value. “If your sensor measures absolutely, you have to subtract something to the environment from the value,” says the expert. “Whether you discount more or less, it’s not a mistake, it’s part of the process. But different results appear. Therefore, the measurement system is not at a reliable technical level. » Ducati chief designer Gigi Daligna also criticizes this fact.

The fact that the situations are far apart has only gradually become clear to MSMA members, race director Mike Webb and technical director Danny Aldridge since 2016. It seems that officials once thought it would be easier to monitor and punish them.

As Team Speed ​​up boss, Luca Boscoscuro allowed Fabio Quartararo to take out the Moto2 win at Motegi without objection due to the lack of 0.05 bars in the rear tire. But great deeds do not allow officials to dance on their heads.

The issue is still sensitive. Manufacturers Michelin suggested some time ago that they should do this and monitor the printing themselves. Then there will be no discussion.

But it is clear that Michelin does not dare to do so.

Because the Michelin technicians themselves cannot predict what tire pressures you should start with until you end up in the lower tolerance range after the race. So, Michelin transfers responsibility to factories and teams.

This is the reality so far.

We ordered from Ing. KTM’s Sebastian Risse sheds some light on a complex tire pressure problem.

Sebastian, the public now knows that these tire pressure sensors do not provide reliable results. It is said that it can be manipulated. Is this true?

A motorcycle manufacturer can turn to a supplier and say, “I want a different one especially for me.” The customer can then express certain special requests and perhaps design one or the other a little differently.

These systems are not standardized or approved. Certainly, there is a “specification sheet” with a certain tolerance. But sometimes this is too big. We are talking about plus / minus 0.175 bar. If you choose the right sensors, you can imagine what happens in the box. Then I immediately gained nearly 0.2 bar.

SPEEDWEEK.com released the tire pressure records for the Jerez race on Tuesday. Does every manufacturer get on this list after the races?

I can’t say anything about it. These are internal agreements of the MSMA Manufacturer Association. There was definitely a request that these records not be shared with anyone. It should not be discussed.

Now the question arises, if a solution has not been found since 2016, how can one suddenly evoke the start of the 2023 season?

Basically, it’s not that everything is a no-go when it comes to tire pressure. You could very well be fined if you don’t follow Michelin’s recommendations and run a tire pressure lower than they describe.

The problem is that the regulations refer to tire pressures while driving in a race. It is hard to predict!

Is there a possibility that the six factories will agree on a standard sensor in the next few months? That all teams push themselves to the limit is clear and understandable.

If a standard sensor for 2023 is selected and the manufacturer provides appropriate support, we can imagine that there will be a common solution.

But the race director or technical director should be able to check if something has been done to the sensor by the factory or team. The electrical infrastructure has to be such that you can’t process anything in the way between the sensor and the login.

If that works, it can work.

However, it remains a difficult task for the teams to correctly predict the tire pressure value at the end of the race. But it’s the same for everyone.

Next, each technician has to decide for himself how much air to emit in each direction.

Because one direction is technically important in terms of regulations, because there are regulations for minimum tire pressure. On the other hand, high tire pressure is critical to the driver in terms of performance and safety. Not because the tire might explode, but because if the pressure is too high, there is a lack of grip and the driving feel.

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