Brembo and motorcycle radial brake development – Part 1
From 300 to 0 km/h in 8.1 seconds

Part One – Part TwoPart Three

Competition is a fundamental element in the evolution of the species, maintained Charles Darwin: the strongest win, propagating their superior traits and contributing to improving their kind. Measure for measure, motorcycle racing is, for Brembo, the most favourable environment for the evolution of its innovations and technological solutions for motorcycles.

Moreover, every new goal reached in motor sports is a new starting point for Brembo. This is why the Group invests its efforts and resources in MotoGP, the premier motorcycle racing class, and 28 World titles won in the 500 class/MotoGP series confirm that this has been the right choice.

A pair of massive ø330 mm Brembo semi-floating discs with a thickness of t5.5 mm deliver superb braking force. Grooves running down the centre of the outer edge of the discs increase their surface area for greater heat dissipation. Dual radial-mount Brembo cast aluminium monobloc calipers grip the front discs. The highly rigid opposed 4-piston calipers with ø30 mm pistons contribute to the Ninja H2’s superb braking force, as well as a high-quality image. Brembo radial-pump master cylinder and reservoir receive extra attention before being shipped to Kawasaki. Each part is examined and adjusted to eliminate any ineffective (idle) stroke. A large ø250 mm disc generates strong braking force at the rear.
Dual radial-mount Brembo cast aluminium monobloc calipers on the modern H2.

The work never stops, because each new victory pushes Brembo on towards new goals – some of which still unimaginable. Very often, however, the pursuit of innovation leads in directions contrary to predefined paradigms, conventions and the norm, as demonstrated by the story of the radial mount caliper, the subject of the monographic section of this book.

It is the story of a concept so visionary and radical that it was initially met with scepticism and even hostility. This was even from the leading lights in the motor sports world, where the drive to win often leads to daring solutions.

Yet, through extraordinary tenacity and desire to outdo itself even above others, Brembo continued to believe in this idea, and imposed this technology first in the racing world and then on the road, to such an extent that it has become the de facto standard for modern motorcycles.

2017 Suzuki Ecstar MotoGP GSX-RR
2017 Suzuki Ecstar MotoGP GSX-RR equipped with Brembo brakes

Brembo also has put together infographics of the 18 Grands Prix of the 2016 MotoGP season, with the most significant figures relative to brake system performance during each race and information on the toughest braking points. These will be included in Part 3.

Included is intriguing facts regarding the circuits of the MotoGP World Championship which, for Brembo, remains the most important test bench for its innovations and technology in the motorcycle world.

Brembo’s continuing commitment to innovation and performance led to all 22 riders competing in latest MotoGP season choosing to entrust Brembo brakes not only with their chances for victory, but with their very lives.

2017 Ducati Launch Desmosedici MotoGP machine with Brembo calipers
2017 Ducati Launch Desmosedici MotoGP machine with Brembo calipers

Similarly and for the same reasons, millions of motorcyclists on roads all over the world trust Brembo brakes to deliver dependable braking performance and keep them safe every single day.

Some innovations hit like a punch in the stomach. Others are simply ahead of their times. And sometimes, to gain a foothold, they have to dismantle prejudice and resistance. This is the story of an innovative product that has forever changed the way motorcycle brakes are designed.

This idea was so bold that it was branded heretical. It took patience, tenacity and a great deal of time to be truly understood and appreciated, precisely for its revolutionary nature. This is the story of the radial mount caliper and how Brembo transformed it from an idea that was deemed too daring even for the extreme world of competition racing, into an object that improves the day-to-day driving experience of millions of bikers.

We’re in the early 1990s and Brembo is already recognised as the undisputed leader in braking systems for Racing bikes. This journey began almost 20 years prior in 1972, when the company produced its first original equipment caliper for street bikes.

Brembo components adorn virtually every high performance motorcycle and Bimota have also chosen proven Brembo monoblock calipers to safely assure there is enough whoa to contain the prodigious go.
Brembo components adorn virtually every high performance motorcycle, a trend seen as far back as the 500cc GP class back in the ’90s.

However, the peak of success came about with the presence of Brembo brakes in the 500cc class at the Motorcycle Grand Prix, the world’s highest expression of motorcycle racing. At that time, all of the motorbikes, including those used in major racing competitions, were equipped with two semi-calipers coupled mechanically and fixed perpendicularly in relation to the fork joint.

With that system, the caliper is fixed to the leg of the fork at the upper point, while the part opposite the mounts – farther away from the fork – remains free. When the pads come into contact with the disc, this applies a tangential force on the caliper in the forward direction of rotation.

It is the most natural and logical solution and it is also the easiest to implement from a production standpoint, especially with traditional forks that require just two ears on the cast leg. The downside  is that the part farthest from the mounts is subjected to more vibration or movement in the solicitation of the brakes.

Regardless and mainly due to a lack of alternatives, up until the 1990s, the axial caliper was the standard for the motorcycle industry. Alternatives were not even remotely imaginable.

Early adoption speed bumps

Things proceeded smoothly for Brembo and there was no reason to venture new, risky solutions. Indeed, the most competitive teams in 500cc in those years used Brembo brakes and the technicians of the Italian company were respected and appreciated in the pits for both their skill and the authenticity of the components.

In spite of this, the active brains of the Brembo technicians began to shape an idea for a motorcycle brake caliper that breathed a revolutionary air. This brake caliper was not only obtained from a single block of aluminium rather than two semi-calipers mechanically coupled, but was also characterised by a radial mount in relation to the fork.

Brembo Formula One Brakes
Brembo Formula One Brakes

Essentially a monobloc radial mount caliper, this was a double jump forward with regards to the state-of-the-art of that era. The inspiration came from a world quite near to the Motorcycle Grand Prix, yet rather distant at the same time: Formula 1.

Brembo has been active in Formula 1 since 1975 and already in 1982 had introduced radial brake calipers for the single-seaters, achieving excellent results. Through sophisticated experience and an understanding of the advantages a radial system can have over an axial system, the Brembo technicians started entertaining the idea of adapting the radial connection and applying it in the motorcycling world.

Brembo two-piece caliper, with axial mount design
Brembo two-piece caliper, with axial mount design

In mechanical terms, radial coupling allows greater stiffness in the caliper, which, following the disc in the rotation phase, makes it subject to less mechanical stress and consequently fewer deformations. The radial mount enables resistance to torque that is significantly higher than what an axial caliper offers because it reduces to a minimum elastic deformation.

The radial mount Brembo used on the 2017 KTM RC250 Moto3 machine
The radial mount Brembo used on the 2017 KTM RC250 Moto3 machine

Conscious of how daring the idea actually was, the designers decided to put off the production of a prototype until they had shown some technical drawings to the man seen as a true guru in the field of motorbikes, a man of great charisma and experience: the Japanese Technical Manager of the Honda Racing Team. Unfortunately, the presentation of the drawings turned out to be a bitter disappointment.

After looking through the sheaf of drawings laid before him, the Japanese Honda Racing manager pushed them away with a puzzled, bewildered expression. Evidently the idea was ahead of its time, so much so that it appeared even heretical. The Honda Racing Team welcomed the concept of the monobloc caliper, but flat out rejected the radial mount.

In Part 2 we’ll see how Brembo successfully introduced the concept to a manufacturer and in turn MotoGP.

Part One – Part TwoPart Three