Welcome to Phillip Island, the closest race to the South Pole
After Dovizioso’s win at Motegi, the MotoGP, where the Movistar Yamaha MotoGP team is sponsored by BMC, stops at the second (of three) Asian-Oceanic race, the Australian GP, scheduled for October 20-22 at Phillip Island Grand Prix circuit, for the 16th race of the season.
Inaugurated in December 1956, the track has hosted the 500 cc MotoGP since 1989 and World Superbike since 1990. Located on Phillip Island 140 km from Melbourne, of all the circuits in the championship, this one is the closest to the South Pole. The last two editions featured rigid temperatures given the position on the 38th parallel south: during the 2015’s race the air temperature was never over 15° C and last year it maxed out at 13° C.
In order to keep the correct operating temperature of the brakes, the MotoGP bikes often use carbon covers, the same they use on other circuits too when it rains. The riders could switch to steel discs when it rains but one month ago in Misano, Marc Marquez proved that it is also possible to race in the rain with Brembo carbon discs without being affected.
According to Brembo technicians, who assist 100% of the 2017 MotoGP pilots, Phillip Island Grand Prix Circuit is only slightly demanding on the brakes. On a scale of 1 to 5, it earned a 1 on the difficulty index, a score that none of the other 17 tracks have earned. The same score was given to the Superbike races.
The demand on the brakes during the GP
Even though there are 12 corners, the Australian track only has six points where the MotoGP bikes use their brakes, which is one less than the Superbikes. No other MotoGP World Champion track requires this little braking: Sachsenring and Spielberg have seven braking sections each.
On average, the brakes are used for 20 seconds per lap at Phillip Island, which comes to 22% of the overall duration of the race. And the nearby icy waters of the Pacific Ocean ease the dispersion of the accumulated heat. The average deceleration is 1,12 G, but for three of the six braking sections, it doesn't exceed 1 G.
Adding up all of the force a rider applies on the brake lever from the starting line to the checkered flag, the result comes in at just over 7,3 tons, the lowest in the entire championship. For the Superbikes however, the value is closer to 6 tons because their races are only 22 laps long, as opposed to the 27 laps of the MotoGP races.
The most demanding braking sections
Of the six braking sectionson the circuit, none are classified as demanding on the brakes, 2 are of medium difficulty and the remaining 4 are light.
With 231 meters of braking space, the first curve after the finish line is the most demanding on the braking system: The MotoGP bikes go from 341 km/h to 189 km/h in 3,3 seconds and the riders experience a deceleration of 1,5 G. On this corner, the Superbikes require less time (2,6 seconds) and less space (173 meters) because they are about 30 km/h slower.
Turn 4 stands out for the load it places on the brake lever (5,1 kg) and the pressure of the Brembo HTC 64T brake fluid, which reaches 8,8 bar. Many consider the speed at which the MotoGP bikes begin to brake here as fairly modest, so to speak: 221 km/h. They continue braking for 4,5 seconds. The figures for the Superbikes are identical except for the pressure of the Brembo brake fluid, which gets up to 11 bar.
In the other four braking sections, the bikes reduce their speeds by less than 100 km/h and so the braking distance doesn't ever go over 150 meters. On turn 9, the riders use their brakes for only 2,6 seconds, which is enough to slow down from 221 km/h to 146 km/h.
BMC News, International Online Magazine