Every motorcycle on the road has brakes, and most bikes use pads and rotors – but how much do you really know about these essential parts, other than that they just make you stop? We wanted to take a deeper look at pads and rotors and how they actually work, so we asked a technical expert at performance braking giant Galfer USA for the inside scoop. Some awesome info here!
Without a doubt, one of the most important, but most underappreciated systems on a motorcycle are its brakes. Brakes are essential for any vehicle – after all, you can only go as fast as you can safely stop – but for motorcycle riders in particular, we have a much more intimate relationship with brakes than drivers of autos do.
In a car or truck, you can just mash the brake pedal as hard as you need to in order to stop. But when we ride, we control our brakes manually, individually applying braking pressure to front and rear brakes separately to get the precise amount of stopping power, just how and where we want it. This gives us much more control over our braking system, but it also gives us a lot more responsibility in making sure our brakes perform correctly, with just the right “feel” for our bike and riding style.
The components that are chiefly responsible for braking feel are your brake pads – or, more specifically, the relationship between your pads and rotors. Assuming everything else in your system is working properly (fluid is fresh, brake pressure is adequate etc.), what determines how your brakes behave – how hard they “bite,” how progressive the feel is, and how long they will last – is what brake pads and rotors you choose to run.
There’s a wide selection of pads and rotors out there that all accomplish stopping your bike completely differently. But because brakes are so important, and because it’s so challenging to know what will really work best for you, we felt this required some explanation from a real expert in the field. So we reached out to the Head of R&D and Engineering at performance brake manufacturer Galfer USA, Chris Phelps, for a one-on-one explanation on how these things work, and how to get the optimal pads and rotors for your bike and riding style. You’ll have a whole new level of understanding of your brakes after reading this!
What goes into a brake pad design that makes one pad work differently from another?
There are two main components in a brake pad: the base, and the friction material. The base is the compound that holds all the friction material together, and the friction material is the stuff that actually bites into the rotor and makes it stop spinning.
At Galfer, we have two of what we call “pad families,” determined by the base they use – our Sintered pads, which use a ceramic base, and our Semi-Metallic pads, which use a carbon organic base. Each of those base materials hold the friction materials together, which are a mix of different particles that create friction, and together, create the pad compound. Back in the day, asbestos was used, but that was outlawed long ago, and in recent years copper used to be a major additive, but the EPA is cracking down on that now also. We’ve phased out copper to be ahead of the curve, and we use a blend of different components for our friction material instead.
In the industry, pretty much all brake pads have the same basic construction and general composition – the trade secret is in the formulation of the friction material itself, which is a recipe that Galfer develops very carefully at our Spain headquarters and keeps a tight lock on.
Another thing a lot of people don’t realize is that the formula for the friction material is actually created for individual motorcycles, in order to get the optimum friction coefficient for that particular model. While we might use a lot of the same friction materials in our pad compounds for a Honda dirt bike or a Yamaha street bike, the formulations will be completely different, in order to create the perfect pad for that particular bike based on initial bite, friction coefficient, heat capacity, and so on.
How are brake pads made?
The process of making a pad is more or less industry standard. First, a backing plate that will hold the pad compound in place is stamped out of metal. Separately, the pad compound, whose formulation is secret and mixed slightly differently for every kind of bike, will be mixed and formed into a pad shape. Then, the pads are heat-sealed onto the backing plate to create an extremely strong bond holding the pad to the backing plate. At Galfer, we subject our pads to extremely high heat during the heat-sealing process, so that they can deal with the tremendous amounts of friction, pressure, and heat they’ll endure in use on our customers bikes.
How are Galfer pads different from the competition?
In creating pads, there are a couple schools of thought a manufacturer can take. The first approach they can take is making a pad that is very aggressive and very long-lasting, which is usually a metallic sintered pad. The down side is, these pads will really eat into a rotor quickly.
Believe it or not, this is actually the approach most OEMs take with the factory brake pads that come installed on new bikes these days. Customers don’t like the idea of maintenance items like brake pads and tires wearing out quickly, and it’s a bad look for the manufacturer when they do and tends to drop customer satisfation. So to prevent that, they lean toward really aggressive pads, which last a lot longer, but also destroy rotors much more quickly. Of course, rotors are much more expensive to replace, and this ends up costing the customer a lot more in the long run, but customers think they are getting longer lasting brakes, and that’s what matters to OEMs.
Since we focus only on optimal brake performance here, we actually take the opposite approach, which is to lean toward softer pads that still provide excellent braking performance and do a great job of preserving costly brake rotors for the long haul. This also means our pads wear out faster, but this is better for the customer – pads are inexpensive and easy to replace, and it’s much easier and less expensive to change pads even several times than it is to change rotors even once.
Speaking of rotors, Galfer is known for their rotors, especially their Wave rotors – what’s so great about them?
Our Wave rotor actually has its origin as a development for Trials bikes, which need excellent brake performance, but often have to deal with mud, dirt, and water in the braking system. The wave design was much better at shedding those foreign elements than standard disc rotors.
But once we developed it, we also ended up seeing many more benefits to the design that hadn’t even occurred to us at first. For example, the serpentine surface of the rotor actually creates a contact patch between pad and rotor that moves up and down rapidly as the pads clamp down onto the rotor. This allows the surfaces of both to cool much more rapidly, which means they experience less brake fade, and thus work better.
The design was so efficient, we discovered we were actually able to remove rotor material to lighten the rotor, without reducing friction or creating excess heat – and of course, lightening rotating mass is great for performance. Now, our development process is to keep removing rotor material and retesting until we see excess heat in test rotors, then we put a little rotor material back in, and that’s the finished product – a different design for every bike that works better and is much lighter than OEM discs. Not to mention, they look a lot better too!
What advice would you give to anyone with respect to the pads and rotors on their bikes?
One that should be obvious ias to change your pads when you change your rotors. You can change pads several times and use the same rotors, but when you put in a new rotor, you should always use a new pad. This is because, as brake pads get used, they tend to wear at an angle, so if you put a new rotor in with old pads, you’ll get unequal pressure on the pads and brakes won’t work as effectively, and may give the sensation of a warped rotor.
Another big one for us here at Galfer – which oddly, few other manufacturers in the industry talk about – is doing the bedding-in process for new pads. Whenever a new set of pads is installed, this process should be done to ensure the best performance, and it really makes a difference in getting them to work their best.
In a nutshell, this is what you do when installing new pads:
- Wipe down the rotor with alcohol (stay away from brake parts cleaner, it is very harsh and can damage other parts.)
- Scrub the entire rotor with 600 grit sandpaper to remove all existing pad material built up on the rotor.
- When the pads are first installed, the surface and friction material will not be fully exposed to the rotor, so you need to do this manually. To do this, do a series of accelerations and full stops. Start by going up to 10 mph, then stop. Then go up to 20 mph, then stop.
- Repeat this process up to 50 mph, then stop, and by then you will have shaved off just enough pad material to expose the friction material. After that, you can ride normall.
One more thing – for the first 100-200 miles, braking power will actually increase as the pad gets broken in. So be conscious of this, especially when doing hard stops, because brake pads will work better after a couple hundred miles on them than they did on day one.