Antonio Cairoli vs Valentino Rossi: differences and similarities in Brembo brakes

9/11/2017

 You cannot win 9 World Titles by chance. Here’s how Brembo brakes are designed to win both in the Motocross World Championship and in MotoGP

Antonio Cairoli has done it: the pilot from Patti (Messina) won the MxGP World Championship 2017. It was a well-deserved triumph for Tony, who took Italy back to the top after two difficult years. The feat was unfortunately not emulated by Valentino Rossi, victim of a fall in training. These two wizards have many aspects in common and equally distinctive characters.

These are the most significant:

 

1) Trophies won: both have won 9 World Championships, 7 of them in the top class.

Valentino Rossi has been faithful to Brembo brakes since starting out in 125cc, in 1996, and he still uses them. With 115 GP victories and 9 World Championships (1997, 1999, 2001, 2002, 2003, 2004, 2005, 2008 and 2009), he is the most successful driver ever with Brembo brakes and the only one to have won the World Championship at 125cc, 250cc, 500cc and MotoGP.

Antonio Cairoli, on the other hand, only started using Brembo brakes in 2010, when he joined Ktm, and he has stuck to them ever since. Since then he has won 54 GPs and 6 World Championships: in 2010, 2011, 2012 and 2013 in Mx1, 2014 and 2017 in MxGP.

 

​ 2) The calipers: both have been using Brembo aluminum brake calipers for years.

Except for the material used, the calipers are very different, as one would expect considering the surface and speeds achieved in the two specialties.
To deal with speeds of over 300 km/h on the asphalt, Valentino Rossi’s Yamaha requires the front of two 4-piston Brembo calipers opposite to the radial attachment, perfect for both performance (from 300 km/h to 100 km/h in less than 5 seconds) and for modularity. Of course, these are billet monoblock calipers, a solution first devised by Brembo almost 20 years ago for the Aprilia 250 and then transferred to the 500cc class.

On Motocross World Championship tracks, however, they rarely exceed 100 km/h and then only for a few moments when soil conditions so allow. Modulability takes precedence over power, indispensable for controlling the motorbike even in conditions of poor grip. For this reason Antonio Cairoli’s Ktm employs a single floating Brembo caliper with two 24 mm pistons.

Compared to the fixed caliper, this solution allows gearing to continue even when there is a disk that has been twisted, not an uncommon event after hitting a rock, a violent contact with another motorbike or a fall. Using a fixed caliper in the event of the disk bending, they can cling to the clamp, leading to the complete locking of the wheel.

Another distinctive feature is the opening on the bridge of the Brembo caliper used by Antonio Cairoli: thanks to this shrewd addition, it avoids the build-up of mud inside the gripper that could hinder the perfect sliding of the disk inside the caliper itself.

 
 

3) The master cylinder and pump-clutch unit: both use front and rear Brembo master cylinders and Brembo pump-clutch units.

 Valentino Rossi and all his MotoGP colleagues have been using radial front master cylinders for years to eliminate any possible torsion in the direction of lever traction.
In other words all the energy released on the lever is conveyed to the braking system without any waste. The gain may seem minimal, but overall, from the start to the checkered flag , a MotoGP driver on average exerts a total load on the brake lever of more than 11 quintals. Dispersing part of this energy would oblige drivers to apply even more force to achieve the same braking result.

At lower speeds, Antonio Cairoli uses an axial front master cylinder with integrated tank, 9 mm piston and 19 mm wheelbase. Its advantages are the greater ease of use, greater strength and less space required on the bike.

For the riding of Cairoli and all MxGP riders, however, the operation of the rear master cylinder is much more important. Antonio uses a 13 mm Brembo pump combined with a billet caliper with 26 mm piston plunger. This pairing allows him to gain inclination going into curves, while avoiding unpleasant sliding. Since both need lightning starts, they rely on Brembo hydraulic clutch pumps: victory is created on the early curves.

 
 

4) Brake disks: both use disk covers to preserve their functionality.

Valentino Rossi uses Brembo carbon disks up to 340 mm in diameter: Their lightness and performance are considerably higher than that of steel, though they need to be brought to at least 300ºC to work properly.

Having a lighter motorbike and travelling at slower speeds, Antonio Cairoli needs smaller disks (260 mm) and a steel braking band. Both use disk covers to preserve the full functionality of the brake discs but for different reasons: Antonio Cairoli usually uses them to prevent mud and sand coming into contact with disks and pads which would cause premature wear of the friction material.

Valentino Rossi, on the other hand, uses them on a wet track to prevent excessive cooling of the Brembo disks.

 

​ 5) Brembo’s different design path

As we have seen so far, both use Brembo braking systems, what changes profoundly is the design approach in the two cases (which we would say are diametrically opposed).

The braking system used by Valentino Rossi has been conceived ad hoc to meet his needs and is the result of experiments that have taken place over years. His MotoGP colleagues have also chosen freely to use Brembo systems with the same specifications (carbon disks and pads, steel brakes, radial brake pumps), although each one has adapted it to suit his own driving style.

The braking system of Antonio Cairoli, on the other hand, comes from what Brembo supplies as the primary system at Ktm and is used in the bikes purchased from dealerships. Starting out from that braking system, Brembo engineers have made some modifications or additions (with some racing components such as the rear brake caliper) to adapt it for use in racing.