Insightful details about braking demands from the Circuito de Jerez on MotoGP machinery, brought to you by the company supplying all the bikes on the grid with brakes.
Begin press release:
With the three non-European rounds out of the way, MotoGP heads to Spain for the fourth round of the 2018 season, scheduled to take place at Circuito de Jerez, May 4-6. Opened December 8, 1985, this track has hosted the premier class since 1987.
In 1992 it became the first track in the Championship to replace the hay bales with air fences. The 2.748-mile track alternates between slow, fast and very fast corners. The 13 turns (eight right-handers and five left-handers) represent 31 percent of the total length and provide numerous places for passing.
The significant changes in slope demand a bike that handles well and that is well balanced, in addition to being stable in braking.
Once again, this year 100 percent of the bikes participating in the MotoGP championship are equipped with Brembo brakes and Brembo’s engineers have assigned a difficulty index for the brakes to each circuit on the calendar.
According to the Brembo engineers who assist all the MotoGP riders, the Circuito de Jerez is the most demanding track on brakes in the first third of the season, out of the first six Grand Prix races, on a scale of 1 to 5, it earned a four on the difficulty index, the same score as Aragon, Buriram and Brno.
On every lap, the riders will have to use the brakes 11 times for a total of 33 seconds. In absolute terms, that is not excessively high, especially if compared with the 38 seconds per lap at Austin and the 37 at Losail. However, on these two tracks, the lap records range from 1:55′ to 2:05′, whereas at Jerez lap times are 1:39 and that gives the Spanish track the highest percentage in the championship of time spent braking, 33 percent.
The presence of three moderate braking sections, in other words, with less than a 22 mph drop in speed, translates into an average race deceleration of just 2.359 lbs. Lowering this average are the values of 1.543 lbs. on turns 4 and 7 and 1.764 lbs. on Turn 10. Only Austin, with 2.028 lbs., has a lower average value.
Adding up all the force the rider applies on the Brembo brake lever from flag to flag, the value is greater than 1.543 tons, a value that Losail and Valencia also reach. In practical terms, on each lap, the rider has to apply a force of 114.6 lbs.
Of the 11 braking sections on the Circuito de Jerez, two are classified as demanding on the brakes and five are of medium difficulty. The remaining four have a low impact on the braking systems.
The most complicated braking section is on the first turn (Expo 92) that comes after a 656 yard straight, which is the longest on the track. The riders begin to brake at 174.6 mph and complete the operation only after 4.6 seconds, during which they cover 239.5 yards. In order to drop to 53 mph, they apply a load of 15.21 lbs. on the brake lever and undergo maximum deceleration of 3.307 lbs.
Braking operations on Turn 6 (Dry Sack) are also quite difficult. The MotoGP bikes go from 182.1 mph to 40.39 mph in 275.6 yards and 5.5 seconds. However, the load on the lever (14.55 lbs.) is lower, as is the pressure of the Brembo HTC 64T brake fluid (166.8 psi) and deceleration is 3.086 lbs., which is 0.4409 lbs. higher than the 124.3 to 0 mph of a Porsche 993 Turbo.
Also noteworthy are the braking system’s 147.9 psi on the second turn, the equivalent of about seven times the pressure of beer on tap. The MotoGP bikes brake for 3.3 seconds to set up the turn at 41 mph, but the deceleration is only 2.425 lbs.
Brembo brakes have won 27 out of the 39 Spanish GP editions, including the last 24. Yamaha has won two of the last three editions, but Honda boasts no less than 17 wins with Brembo brakes. This year, Valentino Rossi is chasing his tenth win at Jerez. He won in 1997 in the 125 class, in 1999 in 250, in 2001 in 500 and six times in MotoGP. Each time he won, he was using Brembo brakes.