Technical: How the MotoGP tire display works

Following the small error from the Eurosport special correspondent Regarding Johann Zarco, we wondered about the functioning of the system which allows the nature of the MotoGP riders' tires to be displayed on the screen. And, more precisely, we sought to find out if a last-minute tire change on the starting grid was taken into account by the system.

Here is the result of our work.

The system is based on the TPMS (Tyre Pressure Monitoring System), these small plastic objects inside the rim, at the valve.

Basically, these TPMS allow you to constantly know the tire pressure and its interior temperature. The signal is transmitted in real time by radio waves and can be read in the same way when the motorcycle is in the box, or can be recorded on board when the motorcycle is moving.

Each TPMS has a unique four-digit serial number and therefore unerringly identifies each rim when it passes one of the four timing loops buried in the asphalt of the track.

After each day of tire fitting, Michelin provides the organization with a database including TPMS serial numbers, name of drivers and type of tires fitted (soft, medium or hard, identified) by reading a Code -Bar displayed on the sidewall (Michelin MotoGP tires do not have any RFID chip to identify them, as this would have required a reading gantry at the exit from Pit-Lane, which Dorna does not want).

Here is a basic table:

TPMS	Pile	Rim / Tire
1234	zarco	Rear / Tender
1235	zarco	Rear / Mid
1236	zarco	Rear / Hard
1237	zarco	Front / Tender

 

From then on, the loops buried in the ground detect at each pass which rims are used, and the computer system then makes it possible to know who they belong to and which tires are mounted on them.
In the event of a change on the starting grid, the electronic system detects it as soon as it passes the start and finish line, and can then display it on the screen.

We can therefore be certain that the indications displayed by Dorna are reliable and that any announcement to the contrary is undoubtedly the result of human error.

For the record, during the last Grand Prix of the Americas, the (charming) Eurosport journalist was undoubtedly misled by a little “trick” from the Johann Zarco/Guy Coulon duo.

In fact, they sometimes do the warm-up lap with a rear tire already in use, only to put the new tire on the starting line, thus increasing its lifespan by one lap. This is what was done in Austin, but with a new medium rear tire, and not soft, as announced.

Photo credit: Michelin & Dorna