The most challenging tracks for 2016 MOTOGP's brakes

3/25/2016

Brembo's forecasts and tacks rank according to brake stress

Dopo la gara inaugurale in Qatar il campionato MotoGP riserva ancora 17 gare.

After the opening race in Qatar the MotGP championship still has 17 races to go. The 2016 season alternates very fast tracks (Phillip Island and Mugello, the average per lap is over 176 Km/h) with slower ones (in Valencia, for examples, the average is 157 Km/h), tracks filled with stop and go's and other characterised by large turns.

Brembo attempts to forecast the stress that brakes undergo in all the Motorbike World Championship's tracks of the queen class.

Number of brakings

It is common opinion that everyone can go full throttle and speed differences are mainly determined by engine power. This is not completely accurate because there are some riders who open the throttle before others gaining precious hundredths of second, but this is a different topic. The difference in terms of riding is mainly visible when braking. Not all circuits have the same number of braking sections: Phillip Island only has 3 per lap, while the tracks that host the first four races of the season have 8 each. Also, not all tracks have the same length. To even everything out we are going to consider a whole Grand Prix which, according to the regulations, provides a coverage of about 110-120 km.

The difference that surfaces is even more pronounced: in Valencia riders have to face 240 braking sections, three times more than Phillip Island who has a little more than 80. But also excluding extreme cases, differences between tracks are still relevant: 120 braking sections in Sepang, 168 in Motegi and 189 in Indianapolis, just to name a few. Anyway, the number of braking sections that characterise a track cannot be considered a reliable parameter to quantify the stress that the braking system undergoes. This value, in fact, does not consider elements such as intensity and difficulty of braking sections. An example is the Valencia track which, despite having 240 braking sections, falls under the Championship's average of braking system's stress.

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Time spent braking and decelerating

In order to make our forecasts more reliable we cross-examined, for each circuit, some "historical" indicators significant for the braking system: the percentage of race spent braking (horizontal axis) and average maximum deceleration that MotoGP's undergo (vertical axis).

The first item quantifies the time spent braking during the whole GP, while the second one provided and objective value of the average maximum intensity of brakes during the same GP, expressed as g deceleration.

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In top-right box the tracks of Motegi and Sepang stand-out for their distance from the centre of Cartesian axis. both are characterised by a high percentage of time spent braking (riders use brakes for at least one quarter of the race) and a high average maximum deceleration of braking sections (higher than 1.4 g) The presence of these two variables represent the worst combination for the Brembo braking systems of MotoGP's.

Opposite, in the bottom-left box, are placed those tracks where the time spent braking is moderate and the average of maximum decelerations is lower for the rider's body and the braking systems. We can thus deduce that Phillip Island and Assen have a low stress for brakes. The stress is "contained" always relatively speaking, because, for instance, at the first turn of the Australian track pilots put a load of 5 kg on the lever to go from 267 to 109 km/h.

In the bottom-right box we find quite slow tracks, as shown by the high percentages of time spent braking, but with not very intense brakings. It is Termas de Rio Hondo and Austin's case, both with 8 brakes per lap, but many of them are constituted by "humane" decelerations.

Not even tracks that are included in the upper-left box shall not be underestimated, because even though brakes are not used much, when they do riders employ them very heavily. This category includes tracks with violent braking sections such as Mugello (San Donato above all) and Brno (especially the first curve of the track) which stress the braking system heavily.

The hardest tracks according to Brembo's technicians

The second chart provides a partially different picture from the one found in the first table. Though this is not enough to complete the analysis because the quantity factors highlighted up to this point must be integrated with quality factors which are hard to measure.
This item includes variables such as asphalt grip (some tracks are used also for car races while others are for motorbikes only), weather conditions, riding style and dynamic characteristics of the motorbike.

Equally important to determine the difficulty of a track for the braking systems are the intensity of braking sections and where they are located: having sequential braking sections like in Aragon is different than having them afar from each other as in Sachsenring because in the first case there is not enough time to let brakes cool down.

Handling all these factor with care is no easy task. But Brembo's technicians, thanks to 40 years on the tracks of the Motorcycle Grand Prix (when the queen class still was 500 with two-stroke engines), know how to manage it. It is proven by the fact that almost all MotoGP riders have been trusting them for years. Drawing from Brembo's technicians expertise we came up with a rank that is partially different from previous lists.

For each one of the 18 tracks of the 2016 World Championship the Brembo engineers involved in MotoGP, assigned a grade from 1 to 5 to assess the stress that the braking system undergoes during the race.

The forecast appointed only 2 track with extreme or significant ease on braking systems: Phillip Island and Assen. 9 tracks, this year, have been forecast with an average difficulty for MotoGP's brakes. The difficulty rate should further increase for Jerez, Spielberg (the conditional here is a must since this track is at his first time in MotoGP), Brno and Aragon ranked as "Hard" (grade 4) by Brembo's technicians.
Finally, there are three tracks which should be particularly hard on Brembo's braking systems: Motegi, Sepang and Barcelona got a 5, the highest grade.

Historically, Motegi's Twin Ring is the hardest track on brakes due to an abundance of second-gear turns that deeply stress the brakes. So it is for the difficulty of cooling-down disks between a braking section and the next: from the first to the tenth curve of the Japanese track it is almost uninterrupted braking. Besides, the flawless pavement provides good grip that allows an optimum discharge of the braking torque without losing adherence from tyres, stressing the braking system heavily.

Sepang is characterised by heavy braking sections from which the first and the last stand-out: both are characterised by violent decelerations with maximum g strengths higher than 1.6 g, 220 km/h of speed reduction from the begging and the end of braking and lever loads of at least 6.5 kg. The high percentage of time spent braking and the Tropical weather making managing temperatures quite critical both for brakes and riders.

Barcelona, the only one of the 3 “very hard” tracks in the first part of the calendar, is a very technical track with sudden brakes that deeply stress the brakes. The highest criticalities for the braking system are caused mainly by the difficulty of cooling down brakes due to the particular layout of the track, sometimes aggravated by the high temperatures of Spanish late Spring. Braking sections, all very intense and close to each other (5 in the first half of the track), cause very high working temperatures for disks and pads which cannot cool-down sufficiently in the mixed part of the track.