As with any upgrade, when shopping for new disc brakes you first need to work out what you need or want from them, compared with what you have now. If it’s simply more power, for instance, you might be able to get that by upgrading to a larger rotor.
If your brakes used to be fine but have become unreliable, the levers or pistons are sticking, or they’ve lost power, don’t assume you need new stoppers. A thorough service/bleed/pad change might get them back to full working order for a fraction of the price. Even if your brakes have never felt great, it’s worth reading the relevant brake reviews here on BikeRadar. It’s a great way to see if your set is performing like it should or whether you’ve got a warranty case.
If you definitely need fresh brakes but your rotors and brackets are the right size, choose a brake that comes just as the lever/body, hose and caliper rather than buying extra rotors and mounts you don’t need.
When it comes to buying your new brakes, make sure they solve the problems you have with the old ones. Try as many different models on the trail (pester your mates) before buying to see how different they can feel and narrow down what you like. If you don’t like the lever feel or positioning of your current brakes, it might be worth investing in a set with bite point adjustment or cam style leverage changes. Read our reviews to check that these features live up to their promise though, because some are more ornamental than useful.
If your current stoppers feel wooden or lack fine control, look for brakes that get praised for excellent modulation. If you want more power, check out our dynometer readings. If you want to shed grams, have a look at the weights on our scales – you might be surprised at how these compare with the manufacturer’s figure. (NB: All brakes have been weighed, priced and tested with 180mm rotors and full post mount kit.) Remember that using a 160mm rather than 180mm front rotor can save up to 50g in bracket and rotor weight, though you will lose a little power.
If you want a brake that’s easy to look after at home, then check our long-term reliability reports, how easy they are to set up in the first place or bleed and service later down the line. Think about pads too – thankfully, many budget brake manufacturers are now smart enough to make their stoppers work with widely available Shimano or Avid pads. It’s still something that’s worth checking if you travel a lot with your bike though.
Key components of a disc brake
Lever: The bit you pull to make the stopping happen comes in various shapes. Pivot positioning and adjustment dials can also change the way each brake feels.
Rotor: The bigger the disc, the more leverage – and so the more power – the brake exerts on the wheel. If you start with a 100mm-diameter rotor, for example, going up 20mm would increase the effective leverage arm by 20 percent. Bigger rotors are heavier though, and aren’t compatible with some forks and frames.
Body: The body holds the lever and clamps on to your handlebar. Some shapes sync better with shifters and suspension/dropper post levers than others. The body also contains the top-up fluid reservoir and the ‘bleed port’ for removing air.
Caliper: The business end of the brake contains one or two pairs of opposing pistons that squeeze the brake pads on to the rotor when you pull the lever. Slotted post mounts are standard but hose positioning and adjustment vary, as do size and weight.
Pads: These tiny pads work extremely hard to turn speed into safely controlled heat. Different brakes use different sizes, shapes and compounds, but some pads are cross-compatible and there are lots of aftermarket options for most brakes too.
Best mountain bike disc brakes
Shimano SLX M675
Outside of extreme gravity situations, Shimano SLX provides unbeatable bangs-per-buck
- Price: £100 / US$130 / AU$240
- Weight: 485g
- Power: 111m/s2
Shimano’s outstanding SLX proves that a top stopper needn't cost the Earth. The lever/body is the same up-and-under cylinder and reservoir layout as the rest of Shimano’s current crop. The short, broad, hooked lever feels great for single finger use and there’s a reach adjuster knob on the knuckle. Unlike XT there’s no ‘free stroke’ bite adjust – but that doesn’t really work anyway, so we’ve certainly never missed it. The safety pinned single-bolt hinged clamp syncs with Shimano’s I Spec shifters.
Modulation and fine control in slippery conditions is excellent and the Servo Wave cam moves the pads quickly to the rotor for a keen but not snatchy feel. The twin cylinder calipers have an outside edge banjo mount and are moderately rather than massively powerful. That means we’d recommend Shimano’s Zee (see below) for proper gravity use. Finned Ice-Tech levers as standard mean SLX doesn’t overheat on big hills or heavy handed use, but you’ll be fine replacing them with cheaper unfinned pads when they eventually wear out if you’re not a caliper cooker.
One of the best things about Shimano brakes at any price is that they’re really easy to live with too. The only slight niggle is that the levers aren’t ambidextrous for easy left/right swapping, but as long as you’re careful you can switch hoses quickly with an 8mm Allen key without re-bleeding.
Unlike many cheaper brakes the hose banjo can also be swivelled for clean routing on all frames and easy bleeding plus included lever joint spares make them particularly suitable for internally routed frames where hose cutting is unavoidable. Weight is high but as usual for Shimano, solid construction means reliability is excellent. The brakes alone offer a bargain, and there’s a range of single-piece, two-part or Ice-Tech bi-metal heat eating rotor options, which are well priced too.
Verdict: Heavy but reliable – powerful enough, with consistent richly controlled performance at a bargain price
- Price: £22.50 / US$61 / AU$N/A
- Weight: 448g
- Power: 77 m/s2
No, that price isn’t a misprint – and we’ve double and triple checked it’s right with Clarks too. So can you really get a 180mm front brake and 160mm rear complete with rotors and brackets for £45 (approx US$56 / AU$67, if you order online)? The simple answer is yes.
Clarks' M2 discs deliver competent performance at a price that beggars belief
Given the history of Clarks we shouldn’t be surprised. Its extensive range of bike brakes has been gradually pushing down the entry price to reliable fully hydraulic stopping for a while now. Though some of the brakes haven’t been great, the recent Skeletal was a solid feeling stopper that’s remained rock-solid reliable under the grimmest long-term use we’ve put it through.
The M2 ushers in a whole new level of affordability. But, Clarks’ Matthew Wright patiently explained when we asked him if he was sure we were looking at the retail price not dealer price, “with Shimano M396 and Avid Elixir 1 prices plummeting we must remain cheap to keep an competitive edge”.
The obvious downside to the discount price is that power is pretty feeble in the 160mm rotor format. That means we definitely recommend the 180mm rotor for aggro trail use – or a larger disc if you’re planning to launch down a DH course. Feel and feedback is actually less wooden than a lot of more expensive brakes though, so arm pump and traction control are much less of an issue. The curved design and gold bore caps mean it doesn’t even look cheap either.
It comes with long-lasting sintered pads as standard and takes Shimano style replacement pads (even the finned ones if you’re feeling fancy) so sourcing spares is easy. We’ve had no trouble with the M2 sets we’ve been running for months and as we say long term experience has been excellent.
Verdict: Low on power, but decent feel, solid reliability and easy spares availability at an unbelievable price
- Price: £130 / US$220 / AU$240
- Weight: 461g
- Power: 147 m/s2
Saint’s cheaper disciple is a huge-power, big-bargain winner for gravity riders with thinner wallets. The dimpled ‘Shorty’ lever and four-pot caliper has obvious similarities with Saint, and while details are downspecced the actual performance is extremely similar.
The brakes actually share more DNA with Deore than with Saint, which means you don’t pay for the largely ineffective ‘free stroke’ bite point adjust of the latter. You don’t get a reach adjuster knob on the knuckle either, just a recessed adjuster bolt. But far more importantly, you do get the Servo Wave cam action that brings the pads in from a wide, mud friendly ‘open’ gap quickly before ramping up the power at rotor contact point. You also get I-Spec shifter syncing.
Shimano's Zee second-tier gravity brakes offer better value than their pricier Saint siblings; power and modulation are still superb
At the far end of the hose you’re getting essentially the same two-piece bolted together four-cylinder caliper. This gives vast amounts of power (around 20 percent more than most trail brakes for a given rotor size) so it needs respect at first. The different sized lead and follower pistons mean fantastic, smoothly squeezed modulation once you adjust to the sheer stopping grunt though. Lack of braking effort keeps fingers and forearms fresher on long descents and better control through jackhammer braking bump sections. Reliability is excellent and one way bleeding is easy and internal edge banjo placement also helps dodge crash/uplift damage.
Obvious cost reducing touches compared with Saint include a painted rather than polished outer face on the calipers and standard non-finned pads retained with a split pin not a threaded bolt. You can always upgrade with Ice-Tech finned pads when the originals wear out. The modular selling model means you can choose basic rotors or Shimano’s unique Ice-Tech steel/alloy sandwich rotors for big mountain heat management if you need to.
Verdict: Massive, superbly modulated, consistently reliable power at a bargain price
Hope Tech 3 V4
- Price: £227.50 / US$273 / AU$450
- Weight: 529g
- Power: 135m/s2
Hope’s biggest brake is a surefire super stopper with excellent rider interfacing. Hope has been machining mountain bike disc brakes since the late 1980s, making the firm one of the most experienced in the field. While machining everything from alloy billet and then assembling it by hand in house in the UK will never be the cheapest way to build a brake, it does provide unmatched quality control.
They're hefty both in weight and cost, but Hope Tech's 3 V4 brakes are a bombproof option
The Tech 3 lever body is an in-your-face piece of industrial design that stands out dramatically from all the other smooth forged brakes available. Its bulk means you get an extra large volume reservoir for improved long descent heat easy bleeding tolerance.
The two-bolt clamp is directly Shimano I Spec shifter compatible and there are SRAM syncing options too. Long drilled levers also add extra practical power to the already very pokey, long pad four-cylinder calliper.
Rock solid lever mounts mean modulation is clean and clear, although not quite as subtly soft-squeezed through the mid range as Shimano or SRAM’s top brakes. Overall control is boosted by simple and effective external dials, which alter lever blade cams for very obvious reach and bite point adjustment. That makes the V4 one of the few brakes you can properly balance left to right – and they’re easy to bleed too.
The meticulously CNC-machined brake is available on its own and there are various rotor options – including heat reducing twin-skin vented for really heavy duty use. High cost and weight are a potential issue, but reinforced braided metal hoses as standard and inside edge banjo attachment make it an outstandingly bombproof brake. Hope’s above and beyond the call of duty factory support is legendary and it sends a service crew to many UK and some European events too.
Verdict: Expensive and weighty, but excellent control, adjustability, power and bombproof reliability
Shimano XTR M9020 Trail
- Price: £229 / US$275 / AU$505
- Weight: 397g
- Power: 115m/s2
Their look may be essentially unchanged, but Shimano’s new XTR brakes get subtle upgrades to improve already outstanding performance. Some niggles have survived the makeover though.
As with Shimano's top-end Saint gravity brakes, its XTR offerings are classy yet niggles make the price tag harder to swallow
While the up-and-under design is the same, new slipperier coatings on the Servo Wave leverage-altering cam of the Trail give increased power over the previous version. Different leverage ratios mean it’s significantly more powerful than the Race version, and the carbon-over-alloy – rather than full carbon – lever blade is tougher too. You get a tool-free reach adjuster on the lever knuckle for fast finger distance fettling too.
It’s still an impressively light system thanks to such details as titanium bolts and general lever clamp and body/caliper shaving though. Power is a match for bigger, heavier four cylinder brakes on the dyno but for once it actually feels more powerful than the lab numbers on the trail.
That’s mainly because the Servo Wave cam ramps up power progressively at just the point the pads hit the rotor. The other factor is the extra confidence from the fantastically rich and communicative single-finger modulation, so you know exactly what’s going on at the tyre and can load it right up to the edge of sliding.
The pads and pistons get better insulated coating for higher heat tolerance. Bleeding is easy and Shimano brake reliability is excellent across the full range.
They’re Shimano I Spec II angle adjustable shifter compatible and the lack of orange anodised detailing seen on the previous version means their more likely to match your rig. The Free Stroke bite point adjuster has more adjustment for potentially faster engagement but it’s still not great. The very effective heat beating Freeza flan fringed rotors are only available in Centerlock splined format too, which limits wheel compatibility dramatically.
Verdict: Super light with luxuriously rich control and excellent reliability but some detail niggles
- Price: £139 / US305 / AU$TBC
- Weight: 405g
- Power: 102ms2
Italian hydraulics specialist Formula has been building motorbike and mountain bike brakes for years – and never sticks with the same design for long. The new C1 brake is Formula’s most affordable aftermarket option and uses a whole new design.
The hose exits on the upper inside edge of the body, leaving the reservoir sat in a distinctive separate ‘nose’. Rather than being built directly into the body, the master cylinder assembly is housed in a separate cartridge that makes building and servicing easier. Formula has decreased minimum lever reach adjustment to work better with small hands, but the pads still bite very early on in the stroke – which won’t suit everyone.
Light and well-controlled, the C1 brakes from Formula are worth a look if you prize weight over power
Dyno power is on par with other twin cylinder brakes but it doesn’t feel quite as pokey on the trail as lab numbers suggest, so a 180mm rotor is certainly recommended for more aggressive trail or enduro use. The power you do get is delivered with typically smooth, easily squeezed and predictably progressive Formula control that you’ll really appreciate in treacherously slippy conditions.
The extended reservoir design also syncs easily with shifters and remote controls and there’s a SRAM compatible combo mount. Increased pad clearance means the C1s are easier to set up than previous Formula brakes too but they still scream if alignment is not bang on. Otherwise weight is impressively low for a mid price brake.
Hardware is more robust than the super light alloy parts found on posher Formulas and there are black or white painted options too. We’ve had no trouble with our long-term sets despite regular downhill track sessions, and others we’ve used on complete bikes have been fine too.
Verdict: Smoothly controlled and lightweight, but power is only average
Shimano Saint M820
- Price: £210 / US$275 / AU$355
- Weight: 474g
- Power: 146m/s2
Shimano’s mighty Saints come marching in with massive power, single-finger control and excellent reliability – but there are some disappoints in the details. The up-and-under reservoir and master cylinder lever body layout is business as usual for Shimano though slightly different in exact shape. The chunky cut, deeply hooked finger-and-a-half lever blade has shallow grip dimples and a tool-free reach adjustment dial.
Shimano's top-line Saint M820 units are superb in many ways, but aren't worth their premium over Zee in our opinion
The crosshead ‘Free Stroke’ bite point adjust screw is stiff to use and doesn’t actually make much difference, so you’ll not always get your lever feel exactly matched. The Servo Wave cam – which brings the brake to bite point quickly before increasing power - is a really neat, and now SRAM-imitated, design though.
Add this leverage multiplication to the already very strong bite of the long pad four-cylinder calipers and it’s one of the most powerful brakes available, on both dyno tests and the trail.
This does mean you’ll potentially be walking back up the trail to find your bike unless you treat these brakes with respect the first few times you ride them. Once you’re used to the cam feel and sheer stopping power, they’re beautifully modulated.
Because you never have to really heave on them, you can single-finger brake through the sketchiest, steepest sections. That means an easier, more assured grip on the bars and less arm pump on really long or particularly demanding descents. Finned ‘radiator’ pads also help dump heat build-up if you’re melting your brakes down proper mountains.
Reliability is excellent and the mineral oil innards are easy to bleed too. The brakes are sold separately but are designed to work with Shimano’s distinctive steel-braking-surface, alloy-core Ice-Tech rotors with Freeza flan fins on the inner edge to dump heat really effectively on long descents.
The Freeza rotors only fit Centerlock splined hubs though – and given that the rather lame Free Stroke feature is all you really get extra, Zee offers far better value.
Verdict: Flagship gravity brake with huge power and control but detail niggles and high price
Hope Tech 3 E4
- Price: £202.50 / US$250 / AU$420
- Weight: 469g
- Power: 109 m/s2
Hope’s extra-modulation four-cylinder brake meets its extra-adjustable Tech 3 lever to build a subtle all-round stopper.
The Tech 3 lever is beautifully carved from alloy billet and then laser-etched and assembled in Hope’s own factory in the northwest of England. The result is a distinctively angular/mechanical look compared with smooth cast competitors.
Hope's 3 E4 brakes are consistent, beautifully made performers but come at a steep cost
The big external knobs give wide and obvious adjustment of both bite point and reach for perfect left to right and front to rear balance. The large reservoir provides plenty of heat capacity for big mountain work too and they’re available with Shimano or SRAM combo mounts if you want.
If you don’t want the extra dials then the Race Evo E4 brake uses a much more minimalist design to save 40g per side, but still has hidden reach adjustment.
Dyno deceleration figures for the beautifully detailed four-cylinder brake are on par with Shimano and SRAM trail brakes. The Hopes have a slightly stiffer, more mechanical feel than the richly squeezed application of SLX or Guide RS, for example.
The drilled lever means no slippage in filthy weather though, and consistency of control and reliability is excellent.
The brakes are sold separately, with Hope offering both single-piece steel and alloy centred floating rotors (as tested here) in a full range of sizes. As they’re built and assembled in-house in Lancashire, various braided hose and occasional special edition upgrades are available to order.
While indulgently sculptural UK machining and building are inevitably reflected in the price, the brakes’ value is boosted by excellent reliability and Hope’s truly outstanding backup in the event of a problem.
Verdict: Decent all-round control with excellent lever adjustment and reliability
Avid Code R
SRAM Guide R
Formula T1 racing
Hope Race Evo X2
With the highest scores going to the cheapest brakes here, you don’t need to spend a fortune to get reliable stopping control. Hope and Shimano prove some premium brakes are worth paying for though, and don’t forget SRAM’s Guide RSC, which scored 4.5 stars in our long-term review.