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MotoGP, At Austin fifty kg of force every minute to brake

The Texan track is the one with the most braking sections: 13, matched only by Losail

MotoGP: At Austin fifty kg of force every minute to brake

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Following the event in South America, MotoGP is moving onto North America for the 3rd race of the 2017 World Championship scheduled for April 21 to 23 at the Circuit of the Americas (Austin, Texas).

The track was designed by German architect Hermann and is one of the few circuits in the world to host both the MotoGP World Championship and Formula 1: the single-seaters register a lap time half a second lower than that of the motorcycles.

Some stretches on the track were inspired by famous corners on historic circuits. The Texan circuit stands out for the intimidating incline on the straightaway leading to the first left-hand turn. In all, there is a difference of 41 meters between the lowest and highest points on the track, which makes it easy to imagine what might happen if the riders make a mistake in braking on the downhill stretch.

The Austin track poses a mid-level challenge on the braking systems. According to Brembo technicians, who assist all of the MotoGP riders, the Circuit of the Americas earned 3 points on a scale of 1 to 5. This is exactly what the tracks at Losail and Termas de Rio Hondo registered, but at Jerez, where the race will be held in two weeks, the score goes up to 4.

The demand on the brakes during the GP - Even though it isn't the longest track in the World Championship, the Circuit of the Americas has the most braking sections per lap: 13. Only the GP Qatar matches this number. While at Losail the riders used their brakes for 37 seconds per lap, in Austin they brake for 38 seconds, twice the time spent braking at Sachsenring.

There are five corners where the riders change direction and brake just what it takes to shave off 30 km/h, which reduces the average peak deceleration per lap. The deceleration on these curves varies between 0.4 G and 0.6 G, which explains the average peak of 0.92 G, the lowest value in the World Championship.

Summing up all of the force applied by a rider on the Brembo brake lever from the starting line to the checkered flag, the result comes in at more than 1100kg. Practically speaking, that means a rider has to apply about 50 kg of force every minute, which is more than a Superbike rider applies. This is why MotoGP riders can use carbon discs, which are thicker than the steel discs used in Superbike.

The most demanding braking sections - Of the 13 braking sections at the Circuit of the Americas, 3 are classified as demanding on the brakes, 2 are of medium difficulty, and the remaining 3 pose only a light challenge on the braking systems.

Curve 12 is the toughest of them all: the bikes enter the corner going over 339 km/h and they brake for 6.3 seconds to go down to 67km/h. The 322 meters of braking is the World Championship record and leads to an average deceleration of 1.5 G.

At the first corner after the finish line however, the load on the Brembo master cylinder lever is higher (6,7 kg vs 6,6 kg at turn 12) as is the pressure on the Brembo HTC 64T brake fluid, which reaches 11.6 bar, almost six times the pressure of a can of 7UP. Yet the bikes are going slower when they start to brake, 184 mph, and they push continuously on the aluminum Brembo calipers for 5.2 seconds.

Turn 11 also requires a load of 6,6 kg on the lever, but the braking distance is 200 meters shorter and the deceleration is 1.4 G. This value is still higher than the 0.18 G in deceleration a Porsche 911 GT3 RS 4.0 experiences when going from 100 to 0 km\h.

Brembo Performance - In the MotoGP of the Americas, the Brembo brakes have monopolized the podium in all four of the races contested. Marc Marquez was the winner every time with Honda, which also won second place two times with Dani Pedrosa. Ducati and Yamaha each placed second one time and third twice.

Translated by Jonathan Blosser
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