I come from an automotive mechanical background and during my apprenticeship I was told ‘Brakes is Life’…whatever you do don’t stuff ‘em up!
Nothing could be truer when your hurtling down the tarmac at 200mph and need to rein in a 160kg monster. But is the weight of the beast really the issue, or is it the speed of today’s bikes that makes stopping them so hard?
Like many of us I was watching the North West 200 during mid-May. Guy Martin caused quite a stir with his comments about being ‘bored to the back teeth’ doing speeds that most of us would be afraid of reaching in a car on the Autobahn, never mind on a road racing circuit in Northern Ireland known for its danger. His comments referred to the number of chicanes that have been added to the circuit over the years, specifically designed to limit speeds when the bikes are going into places like Magherabouy and Metropole. Without these chicanes the bikes would easily be doing in excess of 200mph into tight sections with little or no bail out except for them brakes.
For those of you, (like me) that weren’t paying attention at school braking comes down to a matter of mass and speed, but speed counts for much more than mass. The equation for energy is rather boring but it goes something like this…energy equals one half of mass multiplied by velocity squared. This is the energy (heat) you need to dissipate during braking, so speed is way more important than mass.
Which brings me back to the point…if mass isn’t really the problem then stopping a missile travelling at 220 mph is. Safety is a real concern, whether it is on the roads of Northern Ireland or the tracks of the MotoGP, brakes matter. The organizers of the NW200 realized the inherent dangers of riding today’s bikes at these speeds on open roads and took action to slow things down, but how do the ‘big boys’ do it?
Well firstly some sanity prevailed amongst the MotoGP governing bodies, when in 2014 the FIM allowed the use of 340mm diameter carbon disc front brakes at all MotoGP tracks instead of just Motegi where they were mandatory and the Circuit de Barcelona-Catalunya and Sepang where the use of 340 mm discs was optional.
Data released early in 2014 showed that the factory bikes were reaching speeds of 220 to 225mph on long straights and many riders were finding it a little difficult hauling the machines in. The rule change was introduced on the grounds of safety and although the members of the MSMA (Motorcycle Sports Manufacturers’ Association) could not agree the Safety Commission did, with the rule change introduced just before the Italian Grand Prix in 2014
So what exactly are these carbon brakes and why are they so important in stopping these 260hp beasts, after all the WSBK continues to use conventional steel discs? To better explain things we need to understand the difference between WSBK and MotoGP racing. World Superbikes are designed around a street bike concept whilst Moto GP is a prototype series. The FIM rules for each category dictates what can and can’t be used or modified. Two of the major differences between the individual series are the tyres and the braking systems employed. In a nutshell it is generally easier to stop a Superbike than a MotoGP bike due to a number of factors including speed, weight and grip (of the tyres).
In 2012 MotoGP bikes began generating disk temperatures in excess of 1000 degrees centigrade. That’s way to hot for steel and even as it turns out, for the carbon systems (and braking components) of the day, which in general run at their most efficient between 300 and 800 degrees…hence the introduction of the 340mm discs and a redesign of the monobloc calipers and master cylinders that we see today.
So how long does it take to make one of these high tech carbon discs? Well, according to Brembo brake engineer Lorenzo Bortolozzo ‘its like making a baby’ and for MotoGP that means the process can take up to 9 months! Believe it or not the ceramic discs must spend six months in the oven, baking and curing them so that they can handle the rigors of race day. After cooling they are ultrasonically tested for defects before machining, all the while checking the surface is perfect. Any imperfection on the surface will create vibration which will ultimately be transferred into the hand of the rider.
The pain and suffering of many a rider, especially in MotoGP has generally always resided in their own hands (with a little help from Brembo) so it’s important that these braking systems are not ‘stuffed up’ as my mechanical teachers of the day eloquently put it. And whilst these carbon systems are great in the dry it’s a whole different story in the wet, where due to the lack of heat the standard steel braking systems remain the preferred and better braking option.
I previously mentioned the development of what are known as monobloc calipers. These calipers have quickly become the high performance standard of motorcycle racing around the world and are constructed from a ‘single block’ or ‘billet’ of material, as opposed to the much weaker and ‘springy’ two piece standard caliper design seen on most production bikes.
Monobloc calipers are known for their stiffness and for MotoGP at least were constructed from a lightweight aluminium-lithium alloy. For the 2015 racing season however this material has been prohibited requiring the monobloc calipers to be manufactured using the heavier traditional aluminium. These hand painted, shiny nickel finished calipers are certainly required to pull up todays premier class machines and are the choice for all serious motorcycle racing teams throughout the world.
One of the rule changes MotoGP introduced in 2012, with regards to brakes and safety was the mandatory use of Front Brake Lever Protectors. The mandatory introduction of the protectors had previously been rejected due to fears that in some cases the protectors may cause injury to hands and fingers that in most cases would have been avoided. This fear proved to be groundless however due to a clever bar-end design which today provides protection against the sort of crash experienced by Hector Barbera at Mugelo in 2008. During the 250cc race that year, Marco Simoncelli moved across the track in front of Barbera, clipping his brake lever and launching him over the handlebars and down the track at over 160mph. He was lucky to survive.
Of course that wasn’t the first time this type of incident had occurred in motorcycle racing. During the MotoGP race in 2006 at Catalunya, Sete Gibernau was sent flying when he tangled with Loris Capirossi as they braked going into turn one…the culprit again was an un-protected front brake lever.
Unfortunately on this occasion that wasn’t the end of it. The impact caused Capirossi to move sideways into Marco Melandri, which sent both the Italians hurtling into the back of Danni Pedrosa and John Hopkins in front of them. The chain reaction saw a total of six riders and machines ‘bite the dust’ at high speed and hurtle into the gravel trap that day.
Amazingly Gibernau managed to walk away from the scene of the crash with a fractured collarbone, whilst both Capirossi and Melandri lied motionless on track. After all was said and done, Melandri was diagnosed with a dislocated collarbone, mild concussion and a multitude of minor injuries, whilst Capirossi escaped with non, life threating chest injuries.
Of course that’s not the end of the braking story in MotoGP. Many technologies come and go depending on what today’s high tech teams are trying to achieve. Many riders in recent times have tested the use of ‘Thumb Brakes’ however none of them have been early adopters. Former Repsol Honda rider Mick Doohan is the most famous user of a thumb brake due to leg injuries – necessity being the mother of invention. Perhaps we will only see thumb brakes back in action when performance becomes an issue.
So that’s it. An insight into MotoGP braking and the strategies employed to haul in today’s 260hp monsters.
Brakes is life. Whoa My Donkey