PERFECT BRAKE SET-UP
How to get powerful, reliable and silent brakes in just five easy steps
To maximise your confidence and ride to the best of your abilities, you need to make sure your brakes are totally dialled. In a few simple steps you can tune your brake system to your riding style and local terrain and get them working as efficiently as possible.
Back to basics first: brakes work by converting kinetic energy – or motion – into thermal energy – or heat. So heat is a vital part of any brake system. But too much of it, or too little, and the brakes won’t perform to their full potential.
BLEED/SERVICE
If your brake levers feel spongy, in other words you can still squeeze them after the pads have hit the rotor, then they’re probably going to need bleeding.
We’re not going to cover the process here, as it’s different for every brake, but there are loads of videos showing you how to do it, and we’ve got some good ones on our Youtube channel (mbrmagazine). It’s not a difficult job to do at home if you have a workstand and a bleed kit. Just take your time and follow the instructions and you’ll end up with sweet brakes and save a load of cash compared to taking your bike to a shop.
Another incentive to buy the tools and learn how to do it is that most brakes will need the fluid refreshing every year or two. Just like in your car, the DOT fluid in some mountain bike brakes very gradually absorbs moisture, and water boils at a much lower temperature than brake fluid. Poorly maintained DOT fluid brakes can lead to a lever feeling softer, and in need of a bleed. If you have a brake that uses mineral fluid, such as Shimano, Magura or SRAM’S new
DB8 brakes, the brake fluid won’t need changing so frequently.
If your brakes don’t need bleeding or the fluid replacing, but the pistons aren’t retracting properly into the caliper or the lever isn’t returning immediately after you pull it, then you’ll need to lubricate the pistons.
Wearing gloves – to prevent the oils on your skin from contaminating the rotors – remove the wheel and pads and use brake cleaner or brake fluid to lubricate the piston seals. Use a piston tool to stop the pistons from being pushed out, and pull the lever then work them back in again with the tool. Repeat for a while, and when they are smooth and move freely, thoroughly remove the brake fluid with water or brake cleaner, let them dry off, then reinstall the pads.
BIOMECHANICS
Taking time to get the brake lever in the best position for your fingers and hands will maximise your confidence and control.
All hydraulic mountain bike brakes are designed to be used with just one finger. It doesn’t matter whether you use your index finger or your middle finger, you want your braking finger to sit at the end of the lever, just before the kink. This will stop your finger sliding around and ensure you have maximum leverage.
Now let’s look at the angle of the brake lever. To a certain extent this is down to personal preference, but one tip worth considering is to run your levers at a fairly flat angle. What this does is let you support your weight through your palms and your arms right up into your shoulders, rather than through your wrists. The benefits can include better control over the bike and less arm-pump on longer descents.
The other two components of lever set-up are reach and bite point. These two need to be approached in tandem, as a short reach won’t work with a long lever throw. To a large degree, lever reach will depend on the size of your hand and the length of your fingers. Small hands will want the levers closer to the bar and big hands will need them further away.
You can adjust this with the dial on the front, or by using a hex key inside the lever.
On some brake systems you can also tune the bite point. This refers to the point at which the pads contact the rotor. Set this up to your personal preference, but don’t go too close or too far away. The former can lead to snatchy brakes and pads that drag on the rotors, which wastes energy. The latter can lead to the lever crushing your knuckles before the brakes start doing anything.
BRAKE PADS AND BEDDING IN
There are two basic types of pad on the market: metal sintered and organic. The brown-looking ones are organic and the silvery/grey ones are metal. Most performance mountain bikes run sintered metal pads. Why? Because they offer better performance and durability in wet conditions and on long descents. Organic pads, on the other hand, tend to be quieter and can offer better initial bite, but they wear out quickly in the wet.
Even sintered metal pads can wear down in the blink of an eye in certain conditions though. Welsh trail centres in the rain are brutally tough on brake pads, for example. One way to prolong the life of your pads in the winter is to stick a piece of gaffer tape over the top of the pad slot on the rear caliper. This will help stop wet grit falling in between the pads and the rotor and grinding them down. Just rip the tape off after your ride and give everything a thorough clean to make sure no grit is left inside.
Another important step in making sure your pads don’t wear out prematurely is the bedding-in procedure. Yes, it’s a bit boring, but spending five minutes bedding in your new pads will pay you back with more power, a longer life and less noise. Just find a quiet piece of flat ground and brake from running speed to walking speed repeatedly
ROTORS
until you feel the power come in. This procedure transfers a layer of material from the pad onto the disc rotor, so effectively there are two friction layers working together. If you are moving from a metallic pad to an organic pad, you will need to buy new rotors or sand down the surface of your old rotors with emery cloth before doing the bed-in procedure.
Rotors come in many diameters, from 140mm right up to 250mm. If you can see black or purple scorch marks on the rotor spokes then you’ve cooked your brakes at some point and it might be worth looking at ways of increasing the power. Bigger rotors offer a greater mechanical advantage and also dissipate heat more effectively. So if you’re running 180mm rotors, you could think about sizing up to 200mm rotors. You’ll need to check your frame is compatible first, and you’ll also need to buy new adaptors, but it’s still a cost-effective way to increase your braking power.
It’s also worth thinking about which brake is getting the most use. Most bikes have bigger rotors at the front and smaller rotors at the back, but take a bike on a long descent and it’s always the back brake that gets cooked. That’s because we tend to drag our back brakes when it’s steep or fast, so they get really hot. So it might actually be worth equalising the size of your rotors if you’re doing lots of long descents.