The role of tire pressure, and especially for front tires, has become more important in recent years, as aerodynamics and vehicle height have made the front more sensitive to pressure and temperature changes.
It is common to hear riders complain of soaring temperatures and pressures after getting stuck behind other bikes and obstructing the cooling air.
Therefore, it is not surprising that factories and teams strive to manage tire pressure as carefully as possible.
By reducing pressure, they can keep tire temperatures lower and allow drivers to better manage front tires during the race.
However, they have to be careful not to get too low with the tire pressure: like all motorsports with spec tires, MotoGP has a minimum pressure for both front and rear tires: 1.9 bar front, 1.7 bar behind.
Tire pressure is monitored by sensors and recorded by a spec gauge, and the pressure must exceed the minimum for at least half a race.
Bend the rules
It should also come as no surprise that some teams and factories compete quickly and loosely with the allowable tire pressure. Factories are always looking for an advantage and are ready to exploit when they find one.
What is more surprising is that factories and teams are aware of the minimum pressure rules being ignored, and all accept this as it happens, allowing rule violators to be spared. punishment.
This is revealed by veteran MotoGP journalist Mat Oxley in his latest blog for Motor Sport Magazine.
Oxley has leaked official Michelin tire pressure charts for all teams after the Jerez race, showing that the four riders were riding with too low pressure.
How low can you go?
The rear tire of Andrea Dovizioso’s Yamaha RNF WithU was subjected to the minimum pressure for a lap shorter than the twelve laps required, as was the front tire of Alex Rins’ Suzuki GSX-RR.
However, it was the Ducati riders’ front tires that stood out the most: Jorge Martin’s front tire only had the minimum pressure for a lap, although Pramac Ducati raced out in the last corner of the first lap. first and spend the rest of the race. try to catch up.
However, race winner Pecco Bagnaia had the front tire pressure lower than the minimum for the entire race.
There was not a single lap where his front tire pressure was within the allowable pressure range. And Bagnaia went unpunished, and his victory was allowed to stand.
Angry with the current situation, senior members of rival factories sent Oxley the relevant data.
Despite regulations that state quite clearly that tire pressure must be below a certain minimum, the MSMA – the association that represents the six factories in MotoGP – has a so-called “gentlemen’s agreement” that does not penalize any any violation of the tire pressure rule.
Close the gap
However, that will change next year. When that happened, I spoke with the head of Michelin two-wheel motorsport, Piero Taramasso in Portimão, with Peter Bom.
We talked to him a lot about a number of issues, and one problem that arose was the tire pressure issue.
Mr. Taramasso told us that the minimum tire pressure is in the rule book, but the penalty won’t start to apply until 2023. “This is the regulation, it’s written in all the documents, in rule book,” said the Michelin boss.
“So this procedure has been put in place, but starting next season we will still apply this procedure, but we will impose penalties on teams and drivers who do not respect that. ”
Currently, there are no penalties, only a warning system, Taramasso told us. “At the moment, there isn’t a single penalty, just a warning, such as a yellow card and a red card.”
The fact that all data is published and distributed to all teams after each race is intended to encourage teams and factories to respect the rules.
“Everybody is aware of what is going to happen, which is a good thing. We share all the results with all the teams, all the drivers, so everyone knows who is being respectful or not. So it’s very airy. We work with trust and confidence with everyone. But starting next season there will be penalties for those who don’t respect it.”
Rarely violates
Taramasso tells us that falling below the minimum pressure is not common. “I would say it’s very rare.” Relatively little can be achieved by dropping below the rear tire minimum.
“As for the pressure behind this season, everyone has respect. At the front, it happened twice, one at the wheel and the other at the wheel, different manufacturers. But it was just a little, very, very little,” Taramasso said.
This statement was made ahead of the first MotoGP race back in Europe, in Portimão, after riding on tracks where stability conditions barely prevailed. But two races later, four more names were added to those original two violators.
Taramasso explained in some detail how they monitor tire pressure. The data from the sensors is logged into a data logger, and the tire pressure is monitored and recorded by Michelin technicians before and after each session and each race.
Normally, pressure is obtained wirelessly from the sensor using a handheld device, but when the sensor does not return data, Michelin technicians use a traditional manual pressure gauge.
Based on that data, Michelin was able to determine if the pressures were legit during the race.
“At the moment we measure pressure across all race distances, and for now – but we are discussing whether to change it or not – at least half of the race should be at maximum pressure. minimal,” Taramasso told us. “That’s exactly the rule they use for Moto2. That’s the one we also use in MotoE. “
Because tire pressure increases as racers work their tires during the first few laps of a race, it’s normal for riders to start the race under pressure, he explained.
“The way tires work, you start lower and after four or five laps it goes up to the target and then it stays steady until the end.”
That pressure and tire temperature can be affected by all sorts of factors, including whether the rider is following other bikes.
“Rear pressure is pretty steady, but then the front can go up and down, depending on track, position, etc.”
Fairness & Reliability
As Taramasso explains, the goal is to have an enforceable rule that all manufacturers agree to and are willing to abide by.
Discussions are already underway about exactly what pressure is needed to exceed the race minimum, but the other part of that equation is switching to a single supplier for tire pressure sensors. .
“For a reliable metric, we needed everyone to have the same sensor, and today we have three different manufacturers, so we needed to choose one for this. So everyone has the same, because the tolerances are different,” says Taramasso.
Different sensors have different exacting tolerances which means it can be difficult to compare values recorded between different bikes. This is particularly complicated, since the violations recorded are very close to the allowable values.
More functions, more problems
Reliability will be key. As sensors become more capable and more functions are added, they are also more prone to malfunction.
The pressure sensor has a built-in temperature sensor, but some also have an embedded infrared temperature sensor, to measure the temperature inside the carcass, a more accurate measurement than the temperature of the tire rubber. practical compared to the commonly used simple air temperature sensor.
However, these sensors are usually more fragile. A major manufacturer has moved from more complex sensors like those made by McLaren to fully reliable and proven 2D sensors.
For those who closely monitor tire usage, the weakness of the sensors used is reflected in the tire data.
Currently, sensor data is automatically recorded every time riders enter or exit the pit lane, and displayed on screen using telemetry collected by Dorna.
However, sometimes tire data is missing and must be manually added to the results after the race or session is over.
Even if that data is not recorded, manual measurements can still provide enough information, Taramasso explains. “We have the data because we tick the boxes as they come in and out, so you can deduct how much that is.”
All changes in 2023
The new rules, including penalties, to be in place from 2023 will not just extend beyond racing, as the rules are currently being enforced. “Next year, it will also be for qualifying practice and competition,” explained Taramasso.
Whether that data will be shared with the groups is yet to be decided. Currently, the only data shared with all teams is the data collected during the race.
In light of the accusations made by rival teams, Ducati Corse boss Gigi Dall’Igna spoke to a small group of mostly Italian journalists.
His response was largely a repeat of what we heard by Michelin’s Piero Taramasso in Portimão. You can read a transcript in Italian on the GPOne.com website.
Whether any of these will lead to changes in the short term is unlikely, but the wheels are set to roll out changes for the 2023 season.
Drivers may have to race under the minimum pressure allowed in 2022 and go unpunished. But that won’t happen from next year.
Here to stay
Taramasso told us at Portimão, despite all the controversy that inevitably ensues about being the official supplier of arguably the most important part on a racing motorcycle, Michelin is still in it for a moment. long way. “This is for sure,” the Michelin motorsport boss told us.
Taramasso says Racing has presented unique opportunities to develop their product. “This is one of the reasons we joined MotoGP, it was to grow, to be able to do some tests, to try different things, different tires, different configurations, different covers. together. This is what we want to do. And thanks to the teams, thanks to Dorna we were able to do that.”
The global pandemic has had a negative impact on their plans, he said, but there are big plans for the future.
“The COVID-19 situation slows down a lot, because we have a lot of ideas, but in the future we will be able to do it. One thing we also want to do is develop sustainable materials, such as the ones we use in MotoE. We use recycled and recycled materials. ”
That’s exactly the kind of technology that will go down the road tires very quickly.
Photo: Ducati
