The front tyre is the most important part of a racing motorcycle because it decides how fast you enter corners, ride through corners and therefore exit corners. In other words, without a front tyre that works well you have no chance.
This is particularly true in MotoGP, with Michelin’s super-sensitive front slick, which needs to operate at exactly the right temperature and pressure to perform at its best.
Reducing pressure slightly can improve grip, plus many riders have lost great results in recent years because front tyre pressure increased too much, changing tyre profile and reducing grip.
So, why not run your front tyre pressure a little lower to increase grip and avoid problems?
Because MotoGP has minimum-pressure regulations, written to prevent teams from going too low, which could lead to the tyre casing failing, with inevitable consequences. Other single-make tyre championships, like World Superbike and Formula 1 cars, also feature minimum-pressure limits.
“It’s been clear for a long time that some teams are cheating the tyre rules,”
MotoGP’s minimum limit is 1.9 bar (27.6psi) for front slicks and 1.7 bar (24.6psi) for rears. Any lower and you are breaking the rules, just the same as if you’re running an oversized fuel tank or bypassing software locks in MotoGP’s spec electronics system.
Which begs the question: why weren’t Ducati and Pecco Bagnaia sanctioned for running an illegally low front-slick pressure during their ride to Spanish Grand Prix victory on May 1?
Because there is a so-called gentlemen’s agreement between the MSMA (the manufacturers association) and Michelin to not disclose any breach of this regulation or sanction any breaches.
This agreement has been in effect pretty much since Michelin became MotoGP’s spec tyre supplier in 2016, but at least two manufacturers have now had enough, claiming that they keep their tyres within the rules, while some rivals regularly send their riders out with illegally low tyre pressures, to gain better race-long performance, and suffer no punishment.
By the way, it’s worth pointing out here that the riders probably don’t know they’re breaking the rules – only a very foolish team boss would tell his rider that he’s riding an illegal motorcycle as he goes to the grid.
The leaked Spanish GP tyre-pressure printout, which reveals Pecco Bagnaia and Jorge Martin running illegal pressures throughout the race – Bagnaia’s front tyre was under the minimum for 25 of 25 laps, Martin’s for 24 of 25 laps
In recent months one senior engineer and one team manager from different MotoGP manufacturers have approached me to discuss this issue. Both said they want the gentleman’s agreement replaced by respect for the regulations.
At Jerez the engineer gave me the official post-race tyre-pressure sheet, which indicated four riders running illegal pressures. Two of them – factory Ducati rider Bagnaia and Pramac Ducati rider Jorge Martin – were under the limit for essentially the entire race.
“You cannot have people breaking the rules and getting away with it.”
“It’s been clear for a long time that some teams are cheating the tyre rules,” the engineer told me. “We are really unhappy with this situation – it’s been going on too long and it’s not correct.
“The problem is that most teams respect the rules but some don’t, so they get better tyre performance and they get away with it, because of the agreement. The really bad thing is that we see repeat offenders.
“As everyone knows, MotoGP is incredibly close, with all of us looking for marginal gains to find an advantage. If you can find even a small advantage in one area of the motorcycle then it can make the difference between winning and losing, so why are teams allowed to illegally gain an advantage and no one says anything? This is completely wrong.
“We think the agreement should be dropped and the rules applied correctly, as they are in every other case. In a high-level championship like MotoGP you cannot have people breaking the rules and getting away with it.
All MotoGP wheel rims must feature tyre air pressure sensors (TAPS) to monitor pressure and temperature
“So we call upon the MSMA, Michelin, Dorna and IRTA to fully implement the tyre-pressure rules, because at the moment the situation is not fair at all.”
Since Mugello 2016 all MotoGP wheel rims have had to feature tyre air pressure sensors (TAPS) to monitor pressure and temperature. This data is logged by each machine and checked by Michelin after every race.
The data from Jerez tells us that Bagnaia’s front tyre was below legal pressure for every single lap of the race, while Martin’s was below the limit for 24 of the 25 laps. (Martin slid off on the first lap and quickly remounted.)
Tyre performance is so critical – teams work at adjustments of 0.1 bar or less – that it’s highly unlikely these pressures would’ve been under the legal minimum by mistake.