Decent disc brakes are essential for boosting control and confidence on the trail.
If you’re looking to upgrade the disc brakes on your bike the choice can be a little bewildering. Fortunately most modern disc brakes are reliable and work great, meaning it’s unlikely you’ll buy a dud, but there are big differences in power and feel between brands and models, so doing your research will ensure you choose the best brake for you and your preferred style of riding.
What type of brake you buy may depend on what sort of riding you do, but being able to stop quickly is absolutely fundamental. Power is crucial then, but as the saying goes, it’s nothing without control. How you meter out the power is down to modulation, which comes predominantly from the lever feel.
Of course this is somewhat subjective, but modulation is vital, because it allows you to feather the brakes and tune the level of braking force depending on how much traction is available from your tyres.
A top-performing trail brake shouldn’t cost much more than £120 (per end), but if you’re looking for lighter weight or more power, that can bump the price to over £200. You can cut the budget and get a basic brake for less than £50, although you will lose some functionality and it will be heavier.
What to look for in a mountain bike disc brake:
There are several advantages to being able to remove the pads from the top of the caliper: you can change pads quickly, wear is more obvious and it also makes alignment easier because you can see the rotor from above as it spins through the caliper.
Disc rotors come in several sizes: 140, 160, 170, 180 and 203mm. You can run any size rotor with most brakes but you will need a different adapter if you change sizes.
Standard rotors are cut from a single piece of stainless steel, but there are also two-piece designs consisting of an alloy carrier with a stainless steel braking surface. They’re more expensive but the smaller braking surface is truer and less likely to warp.
To accommodate different hand sizes, disc brakes have reach adjustment. Tuning is done with either a grub screw or a dial on the lever. With this you can adjust the lever position relative to the bars to suit your hand size, and to a lesser extent, personal preference.
A split clamp allows you to remove the brake lever without removing the grips. The clamp can also be replaced via a MatchMaker-compatible design, allowing you to piggyback a shifter directly to the lever body, saving weight and de-cluttering the bar.
Some brakes have Kevlar or braided hoses, which are less compressive and can boost performance. The hose is usually cut to length for the front and rear brakes, but it’s easy to shorten if not, although you may have to bleed the brake afterwards.
Spare olives and hose inserts should be included in the box. These fittings attach the hose
to the lever, and having spares is useful in case you have to trim the hose when you first fit the brake.
SRAM Guide RE
SRAM didn’t develop the RE for regular trail bikes, but since it costs the same as the cheapest Guide brake, only adds 35g, and packs Code levels of power, we’re totally sold on it for regular trail use, especially if you’re a heavy or more aggressive rider.
SRAM Level TLM disc
As an XC brake, the Level TLM is sleek, lightweight and easy to set up and service. If you don’t weigh much, you could probably get away with it on a short-travel trail bike, but if you ride more aggressively, we’d recommend the Guide instead, as it’s a lot more capable.
Shimano XTR Race disc
Shimano offers two XTR brakes: Trail and Race. The latter lacks the power-boosting ServoWave lever design and finned brake pads, but it is lighter as a result. The Shimano XTR Race delivers unbeatable value and performance and is easy to set up and bleed as well.
Shimano Alivio disc
Shimano’s Alivio brake is a popular choice on hardtails and entry-level full-suspension bikes, and we’ve ridden dozens of sets over the past couple of years. Come rain or shine, on smooth local trails, ragged BikePark Wales runs or lift-assisted laps in the Alps, it’s never let us down.
Sram Guide Ultimate disc
SRAM has really nailed the lever feel and position on the Ultimate, and while we used the minimum Contact Point Adjustment setting, the wide range of adjustability makes it easy to get your preferred lever feel. Not cheap, but they do offer unrivalled control.
Avid DB3 disc
With the lever pivot really close to the bar, you get improved control — one-finger braking is all you need. We like the split clamp too, and its compatibility with Matchmaker mounts lets you clean up your cockpit, but it’s the impressive feel and power that really makes the Avid DB3 stand out.
Hope Tech 3 E4 disc
The caliper doesn’t sport any clever heat shields or fancy backing materials on the pads, but we had no issues with heat build-up or inconsistent braking power. In fact, the opposite was true; the Hope Tech 3 E4 offered the most reliable performance in test, with zero lever pump or brake fade. It isn’t the most powerful, though, and would benefit from a little more progression.
Clarks M2 disc
Overall performance was good, if a notch or two below its competitors. We put this down to a couple of things. Firstly the pads don’t sweep the full braking surface of the rotor; around 3mm is left untouched.
Formula R1 Racing disc
With its oversized pistons and Kevlar hose, the Formula R1 Racing is the most powerful brake here. It’s also the lightest, but the stumpy lever is a little uncomfortable when braking hard; it also needs constant fiddling to run drag-free.
Shimano Saint disc
The Shimano Saint brakes come at a great price but are harder to modulate than other four piston brakes. There’s still a lot of dead lever travel, though; the free stroke adjuster is all but useless, and the power ramps up suddenly, making it much harder to modulate than other brakes in this price range. There’s no arguing with the Saint’s price, though.
Shimano XT M8000 disc
Shimano’s XT brakes have long held a reputation as being ultra-reliable. Unfortunately, on prolonged descents, issues ranging from wild shifts in bite point, to inconsistent power, frequently spoiled our ride with the new M8000 model. In a nutshell, if we hadn’t had the significant teething issues with the M8000, you’d be reading a rating much closer to top marks here.
Above: How to stop disc brake noise
We said earlier that the ideal brake has to be both powerful and well modulated. If it’s underpowered, you’ll end up pulling too hard to slow down, which can affect the way you set up for a corner or ride a technical section.
Conversely, if the brake is too harsh, you can over-brake coming into a corner, losing grip and traction. Fortunately, most of the brakes in this test have sufficient power, but it’s the combination of feel, lever shape, ease of set-up and reliability that gain top scores.
Despite the low price of the budget brakes, they still work great. The Shimano Alivio has great power a comfortable lever and is easy to set up. When you factor in the bleed kit, it’s also great value.
Lightweight disc brakes are obviously all about weight saving, but there is a law of diminishing returns. You really have to ask yourself whether saving the weight is worth the cost. The Shimano XTR brakes come at a great price without a delicate feeling.
When you need to scrub off a load of speed, a four-pot brake really comes into its own. Feel is key, but of equal importance is stopping power and heat management (and reliability, of course, but that’s a given).
Top of the four-piston brakes is SRAM’s Guide Ultimate — pricey but with great lever feel, tons of power and able to handle Alpine riding with ease. For these reasons, it really is the ultimate.