Brembo, and the art of stopping pilots

Brake, brake, brake! Every lap always the same way, with the same insane deceleration. Without extending lever travel, without symptoms of overheating failure. In the dry as in the wet, in the mugginess of Malaysia as in the cold of Germany. If Marquez, Dovizioso & Co can go from 355 to 90 km/h in 4.2 seconds, as happens at Mugello before San Donato, the merit goes to Brembo. That opened the doors of his racing department to NetBikers

 

There is a girl in the Brembo factory in Curno, that mounts the brake calipers of all the MotoGP riders. She does it smiling, with a pinch of good mood, and to finish and deliberate a clamp she takes a lot of time. She does a lot of testing with precision equipment, and if she is not satisfied, she disassembles them and starts over. Finally, she puts a small code on the clamp with a marker pen. And she puts it on the table next to her workstation. When I saw her she put 4 calipers in a row on the table. They looked like works of art. Polished, very shiny, because this kind of work is done in an environment similar to an operating theatre. I would have liked to take one in my hand, to admire it better and weigh it. But I knew that it couldn’t be done, so I admired them holding my hands in my pocket. And today I tell you all about it. Because, obviously, it was totally forbidden to take pictures.

“The life of all MotoGP riders is in the hands of that girl, who assembles all their brake calipers” said Lorenzo Bortolotto, our guide when visiting the Brembo MotoGP assembly department. He is one of the two track engineers at the Bergamo-based company who follow the World Championship teams. Lorenzo is very passionate about his work and he had already entertained us in the morning in the classroom, with a deep and fun technical presentation. Above all, he answered our questions, without ever refusing to back down.

 

Comparison of MotoGP and road brakes

 

“We are following your activity on the web with great attention and for this reason, we have decided to invite you to the Brembo Digital Press Racing Conference on March 14. The press meeting dedicated to motorcycles sports specialists on the web”.

This was the opening of the email sent to me by the iconic manufacturer of braking systems for motorcycles and cars.
And so here I am on a sunny and warm morning, crossing the gate of the factory. In the meeting room, with the glass window overlooking the production line of the car systems, there are already 5 other colleagues. Bloggers. The day is dedicated to us who write on the web.

 

Two pieces calipers machining

Some Numbers
It starts with a presentation of the company. In 2016, turnover was €2,279 million, up 9.9% compared to the previous year; a trend confirmed also in the 2017 financial year (€2463.6 million). Employees now amount to almost 10 thousand, considering all Brembo plants scattered throughout 15 different countries around the world. 10% of the workforce is employed in R&D departments, with a dedicated turnover of 5%. And here in Curno a new “Carbon factory” is being built, a production line dedicated to carbon fibre, which will allow the company to take home and tightly control every production cycle of this high-quality material. As it does already with steel and cast iron, being also the owner of foundry departments. Brembo also owns the Marchesini (wheels) and AP Racing brands.

 

The technology behind MotoGP brakes
The presentation begins, and the discussion goes straight to the technical level. We are shown MotoGP brakes that have been built. The front calipers are of two types, called Heavy duty and Light duty. Riders choose them according to their driving style, but also according to the track. Heavy riders and those that brake very hard, choose the former, the Heavy duty ones, which have a slightly higher mass and slightly larger pads, to dissipate more heat and avoid deformations. The most massive calipers are also used on circuits where the brakes are under greatest stress, i.e. Japan and Austria.
Temperature is a very important issue for braking systems. Carbon brakes have a range of operation from 250 to 850 degrees. Below this range they don’t brake much, temperature above this range triggers a process of carbon oxidation that can lead to wear of the material in just 3 laps of the track, with serious risks for the pilot.

 

For steel, the temperature range is 100 to 600 degrees. In this case, reaching a higher temperature can lead to deformation of the disc, with dangerous vibrations.
The reason for the shift to carbon even in wet weather is perhaps also here. In fact, Mr Bortolotto tells us that with steel brakes, the temperature safety limit was too close to the limit. So they put pressure on riders and teams to switch to carbon. “But it was not easy. It took us 6 years to convince them. For a psychological fact. Fortunately, Marquez found the courage to break the deadlock. Now everyone has changed their mindset and is using carbon without any problems, even on water.

As for discs, pilots have several to choose from. And here too the problem is temperature. On very demanding tracks, therefore, heavier components are used, while on easier tracks lighter components are chosen, ones that have a lot of air gaps between the braking track and the supporting flange.
As for the diameter, the 340 mm ones have been used almost everywhere, compared to a few years ago when 320 mm ones were used. The reason? Bridgestone tyres in use at the time had a particularly stiff shoulder, requiring riders to brake very hard and powerfully to press the tyre to the asphalt and achieve maximum grip. A braking technique that overheated the discs. And so the diameter has increased. And today they tend to be used with a single diameter because this makes it easier to change wheels in races with variable weather.
Incidentally, pipe connections on calipers and pumps do not have the classic threaded ring nut we all know, but a quick snap-on connection. This allows quick disassembly and reassembly of the braking system if engineers need to work on the motorcycle.

 

Automated three-dimensional inspection of finished parts

The research and testing phase
Computer simulations are obviously essential during the design process. Loads and tensions, but also air flows, are evaluated. For this reason it is essential to have 3d profiles of all components. This creates some problems, because, while there are no problems for rims and forks, tyre manufacturers are very jealous of their tyre profiles. So computer simulations… lack tyres.
Then we move on to actual tests. The first bench is static, and brings up the brake operating pressures until calipers are broken. To measure the maximum limit of the product under development, and any potential vulnerabilities. Then they move on to a second bench, which reproduces a dynamic test. It may seem like a braking system mounted on a lathe, with a computer simulating specific cycles.

For competitions, track laps are simulated on different racetracks. Therefore, to evaluate the operation in MotoGP, they use the Motegi cycle (the hardest) and the Assen cycle (the smoothest). For the SBK they use the Monza cycle because the Italian circuit is a particularly demanding one for brakes. Obviously there is a third phase of testing that is hands-on. So we are talking about motorcycles on the track for competitions, but also road vehicles, and with different climates, for road systems.

 

Aluminium, magnesium, carbon fibre and titanium
Finally, a brief on materials. For the calipers they use aluminium, with the realization from a single block of aluminium material, starting from the piece of material coming from the foundry. For two years now, the aluminium-lithium alloy – had superior rigidity qualities – has been banned. Therefore the size and weight of calipers have increased slightly.
Pistons are made of titanium for weight-saving reasons. The brake pad plates that work on steel discs are made of titanium. For carbon discs, the pads are made of carbon. And the production cycle of each carbon component is 7 months!

Master cylinders are made in forged aluminium. That is, a cast aluminium that is processed with pullovers that compact the molten metal, in order to increase its mechanical qualities.
The same manufacturing process is used for aluminium or magnesium blocks used to make wheels. With one important difference: because magnesium is highly flammable, it is dry worked at low speed. Because the supply of water in the event of a fire would risk providing additional oxygen to the combustion and feeding it. The burning magnesium is not extinguished with water!
Magnesium wheels no longer have the yellow colour we saw in the past. That was due to the anti-corrosion treatment with hexavalent chromium, which is now prohibited. A different treatment is therefore used, which does not alter the original light grey colour of the material.

The visit continues. We enter different areas of the racing department. We also see some components for Formula One and Rally cars. Stacks of completed discs, ready for delivery to teams. Impressive brake calipers as large as those we see on trains, for cars with very high performance. Raw material, and shelves with rear wheels at various levels of finish. They do not let us access the Formula One department, because there are technicians of a team that are discussing with Brembo engineers the development of the calipers for their single-seater, and do not like prying eyes.

Everything is so close at hand. Everything is so refined, everything seems easy. The atmosphere is cheerful, we chat while walking through the workstations. They also trusted our commitment not to take pictures, and left the phones in our pockets. It is not common, in other companies in order to enter you have to hand over the phone at the entrance.
The visit is over. They give us a USB stick with a temporary link to download everything and more about Brembo. Everything and more, so much so that here you will find only a selection of the most important things. We will tell you the rest little by little.
Meanwhile, if you want to go further in deep, scroll down after the video and photo series. You will find the description of the components available to MotoGP riders for the 2018 season.

 

 

It all starts with this aluminium block

 

The monobloc caliper starts to take shape

 

And here’s the end result

 

Manufacturing from the aluminium block shown 3 photos here above, is carried out by this 5-axis CNC milling machine

 

The Curno plant also produces Marchesini racing rims

 

The final stage of production is the manual removal of burrs. The staff is mostly female because… it seems that women are more precise!

 

Brembo brakes 2018 MotoGP season

For the third consecutive season 100% of MotoGP riders has decided to rely on the high performance, reliability and safety levels guaranteed by Brembo components: brake calipers, discs, brake master cylinders, friction master cylinders and pads.

From the introduction of the MotoGP series in 2002, all the 278 GPs have been won by motorcycles using Brembo brakes. The winning series in the premier bike racing category is longer as the last GP won in the 500 class with a motorcycle without Brembo components is dated 1995.

The Company leader in the production of braking systems continues in the development work of braking system, in order to guarantee to all riders maximum performances, optimization of feeling and absolute safety. In addition, Brembo is focused on satisfying the requirements of the different teams, offering an extensive “customization” of brake systems, deriving from the optimization of the specific requests of the riders.

For the 2018 season, Brembo proposes to teams a furtherly extended offer of braking solutions for the premier bike racing series providing for each component of the braking system different technical options available for teams and riders. A wide range of technical solutions allowing to guarantee to each rider the possibility to “customize” the braking system in function of driving style, track features and race strategy.

Two types of aluminium calipers are available for the 2018 season (Light duty and Heavy duty) and for use with carbon pads (High Mass and Standard). Much more numerous are the options concerning brake discs, brake master cylinders and wheels.

Due to the absence of regulation novelties and the use of tyres with the same construction and profile of the 2017 season, Brembo technicians working in close contact with the teams expect a braking behaviour not changed much compared to last season.

Brake discs available to MotoGP riders

10 solutions of carbon brake discs
The majority of riders should choose discs with diameter of 340 mm, dividing between High Mass and Standard (low mass). To ensure the same braking torque and obtain a further lightening, Brembo has introduced Light discs with 340 mm diameter. Some teams instead will continue to use Standard and High Mass discs with 320 mm diameter.

Furthermore, for each format of brake disc and pad are available two different carbon compounds differing for initial bite and resistance to high temperatures.
Overall 10 are the different options available for riders as regards the choice of brake discs.

After the result of Japan Grand Prix of last October, with the first 9 riders at finish line with motorbikes equipped with carbon discs despite the strong rain, more riders will renounce to steel discs even with rainfalls.

Carbon ensures a triple advantage: reduction of not suspended masses, friction coefficient identical from the start to the finish line and absence of residual torque issues that can concern
steel discs.

2 types of thumb master cylinder systems
Different are the types of brake master cylinders available for the teams in terms of wheelbase, in order to adapt both the race and the “reactivity” of the control as a function of the feeling of rider. In addition, each motorcycle features the remote adjuster, used by rider with the left hand to vary the position of the brake lever even while lapping the circuit.

Brembo signals that more than a third of MotoGP riders uses regularly the thumb master cylinder. This technical solution, introduced by the Italian Company in Nineties to support Mick Doohan, allows the activation of rear brake by pressing a special lever placed on the left semi-handlebar. Two are the variants of thumb master cylinder systems in use for the 2018 season: the most widespread features a unique circuit of thumb master cylinder and pedal, using a rear 2 piston caliper. The alternative, instead, features two separate circuits, each of which acts on 2 of 4 pistons of the rear caliper. In the first option a system excludes the other, in the second can act simultaneously.

3 options of Marchesini wheels
This year also sees Marchesini forged magnesium wheels used by the majority of the riders competing in MotoGP. 7-spoke Marchesini wheels are realized in 3 variants for the front and rear wheel: a lighter but less stiff solution, one more stiff but also heavier and one in the middle of the two options. The Marchesini (Brembo Group brand) wheels ensure weight savings to the motorcycles, favouring acceleration and handling in changing direction.

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