317 meters (1040 feet) of hard braking and brakes that reach a temperature of 700°C (1,292°F): this is Mugello

5/25/2021

The incredible braking data for the Italian GP and the secrets of the Brembo brake fluid for MotoGP and your motorbike

According to the Brembo technicians who work closely with all the MotoGP World Championship riders, the Mugello Circuit is a moderately demanding circuit for brakes. On a scale of 1 to 5, it is rated 3 on the difficulty index, the same as the other Italian track for racing fixtures, Misano Adriatico.

The Tuscan track also boasts one of the longest straights in the Championship calendar (1.141 km/0.709 mi) which demands a powerful engine and, naturally, a top-notch braking system so what you have gained on the straight in braking is not lost. Fortunately, the distance between the remaining 14 corners allows the carbon fiber discs to cool down.

Brembo brake fluid can rise to 300°C without reaching boiling point

In addition to brake calipers, discs, pads, brake master cylinders and clutch master cylinders, Brembo also supplies all the MotoGP riders with brake fluid. Two types are available: HTC64 brake fluid has higher heat resistance but lower hygroscopic properties. This refers to its ability to absorb the water (moisture) in the atmosphere.

For this reason, if humidity is high, the brake fluid must be replaced once a day. LFC 600 brake fluid which teams opt for when temperatures are low needs to be replaced much less frequently and is more stable as far as compressibility is concerned and more hygroscopic. They also have different dry boiling points: approximately 315°C for the LFC 600 fluid and 335°C for the HTC64 fluid.

Brake fluids for road motorcycles

LCF 600 Plus fluid is commercially available although it is recommended for track use: since it has a high hygroscopic level, it has a limited lifespan. This depends on a number of factors, but it usually ranges from 2,000 to 4000 km (1242 to 2485 miles). It can be mixed with other DOT3 and DOT4 racing fluids but should not be used in brake systems with magnesium parts.

The Brembo Sport.Evo 500++ DOT4 fluid, on the other hand, has a dry boiling point of 270°C (518° F) and is recommended for road use without compromising performance. Its excellent properties help it to reach a high mileage before it has to be replaced, usually from 12,000 to 24,000 km (7456 to 14912 miles). However, it should not be used in brake systems designed for mineral fluids.

You can see the characteristics of Brembo brake fluids here.

200 kgf (440.9 lbf) less physical effort 

MotoGP riders use Brembo brakes 9 times per lap, for a total 29 seconds, amounting to 28% of the overall race time. This is the lowest percentage of all the GPs which have been raced since the start of the season: in Jerez and Le Mans it is 34%, in Portimao 33% and Losail 30%.

When summing up all the forces applied by a rider to the Brembo brake lever from the starting line to the checkered flag, the value amounts to over 780 kgf (1719 lbf), approximately 200 kgf (440.9 lbf) less than the Le Mans and Jerez races. The reason for this lies with 5 braking events where the force applied to the lever is between 4 and 5 kgf, 4 of which have a deceleration of 1.1-1.2 g.

317 meters (1040 feet) of hard braking 

Of the 9 braking sections at the Mugello circuit, 2 are classified as demanding on the brakes, 4 are of medium difficulty and the remaining 3 are relatively light.

The hardest braking event is the one at San Donato (turn 1): preceded by a downhill section, the MotoGPs approach at over 330 km/h (205 mph) (the Ducatis even faster) and start the turn at 93 km/h. To do this, the riders apply the brakes for 5.9 seconds and cover a distance of 317 meters (1040 feet). There is massive deceleration (1.5G), the brake fluid reaches 9.9 bar and the temperature of the brake discs 770°C (1418°F).