Before it even begins, it seems more than likely that the 2023 MotoGP season will be all about front tire pressure management. Multiple signs seem to indicate this, from the problems encountered more and more frequently by certain drivers to the sanctions planned this year by Dorna Sports, and this is why it seems useful to us to study in depth a subject of which very few people imagine today the importance and the level of technicality.
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5/ The solutions adopted by the teams…
The sensors that record pressure are discharged after each run. The teams also have internal and external temperature sensors for the front and rear tires.
Since 2022, Michelin has provided Dorna with the list of pressures recorded, in the form of a table with red, orange and green colors, therefore without numerical values. This table is then redistributed to all MotoGP teams.
With a pressure which can vary by 0,4 bar while the operating range of the front tire is concretely only 0,25 bar, the teams have no other solution than to start the race with a pressure not regulatory, hoping that this, carefully calculated, will correspond to the regulations at the end of the event.
Today, Yamaha is the only MotoGP team to use nitrogen to try to reduce the phenomenon: as soon as the tires, mounted and inflated with dehydrated air by Michelin, return to the box fabio quartararo et Franco Morbidelli, they are immediately deflated before being reinflated with nitrogen. But that doesn't change the problem: in practice, if the pressure rises largely because of the humidity contained in the volume of the tire and the rim, whether dehydrated air or nitrogen is used, the tire “makes water” by heating, and there’s nothing we can do about that. We even managed to find traces of condensation inside the rim when removing the tire!
So at Yamaha, as with all the other manufacturers who have already tried nitrogen in vain, we calculate by trying to imagine the race as best as possible...
« Today, all brands have tons of data and have developed heat blanket temperature charts to obtain the pressure during the race, depending on the starting position and the competing bikes in front : the Ducati being reputed to be easy to overtake, the teams take the pressure off a little more if they expect the rider to ride in a pack for a good while behind the Desmosedici. On the contrary, a driver who expects to ride alone will be able to apply a little more pressure. »
“We have calculation tables that recalculate the temperature of the tire based on the temperature of the heating blanket. The covers may indicate 90°, but this is not at all the temperature of the tires, which can vary quite a bit depending on their positions in the heating cabinet: at the top or bottom, on the sides, etc., it there is up to 10° of difference, therefore 0,1 bar. For us, this is huge! We therefore have an instant connection with the sensors which are in the wheels, we know the temperature of the air, the rim and the rest, and we have software which gives us the right pressure to put according to the value of basis that we want. »
« All drivers have a front tire pressure alarm on the dashboard, some even with the numerical value. »
« During the race, the driver has pressure alerts on the dashboard: At the four corners of the dashboard, there are four colored lights that indicate too high or too low pressure in the front and rear tire, in order to warn before each turn if the pressure is correct. At the rear, the driver will feel incorrect pressure more easily, because it will be when accelerating, but at the front, if the pressure is too high, he will find himself on the ground entering a corner without having had time to to understand. »
« We have plenty of systems to influence the temperature, in particular with disc covers and mudguards. But in terms of pressure, it will affect 0,05 bar. »
6/ Cheating or not cheating?
It's obvious: by starting with non-regulatory pressure, there is a risk of ending the race with too low a pressure, if the driver is driving alone and is not incisive enough. But no sanctions were applied in 2022, due to the non-calibration of the internal sensors of different brands which equip the different manufacturers. Some people quickly understood this and have been putting into practice this simple reminder policy for years... but this mainly concerns the rear tire.
« In MotoGP, for a very long time, only Aprilia was white as snow in terms of pressure, which is no longer true, since they saw that the Ducati were regularly in red (on the table established by Michelin) and finished on the podiums without being sanctioned in the least. At Yamaha, there were some resounding errors because overall the Japanese are terrified at the idea of being disqualified for too low a pressure since Maverick Viñales' victory at Sepang. They are now taking a margin of safety, which has occasionally generated pressure that is much too high for Fabio Quartararo.. The others are between Yamaha and Ducati. »
«No team seeks to ride with too low a pressure at the front, although at the rear it can happen at the rear despite premature wear over the length of the race. »
«I would say that there is not really intentional cheating on the front tire pressure : it's more of a bad estimate of position in the group and aspirations. »
