How we test hydraulic disc brakes

Mechanical dyno adds science to the review process

In mountain biking, nothing is more important than being able to stop. That's why our disc brake super-test is probably the most comprehensive, in-depth data gathering feature we do every year. For the latest reviews in Mountain Biking UK, What Mountain Bike and on BikeRadar, we've rounded up 33 different models and split the testing into two halves: real-life trail testing all over the world and mechanical dyno testing.

How we tested them

We test brakes probably hundreds of times every time we ride, accumulating a vast amount of experience and a very broad range of reference in the process. We run long-term sets of all the current models and types of brake as soon as they’re available and circulate them round our test crew constantly.

We also take brakes into intensive-use environments – from gritty moors to mountain downhill courses – as often as possible, and our rider feedback group includes professional mountain bike guides from all over the globe, letting us know what works in the hardest conditions from Whistler to Morocco. We’ve also grilled enduro racers, downhill coaches and shop wrenches to get their time-proven opinions on which stoppers work for them and the people they work with.

2011 has been a very interesting and intensive year for brake testing, with both the product range and our conclusions being totally different to what we’d have come out with 12 months ago. That means we’ve had to put miles and miles and months and months into whole new families of brakes as well as major revisions of known species. 

With the riding info collected, we then took fresh front sets of every brake (except for the Magura MT8, where only a previously used sample was available; this may have affected the figures for that brake) to a state-of-the-art dynometer testing facility to put some figures behind the trail feedback. This gave us not only raw stopping power results, but also confirmed how the brakes applied their power and how they coped with heat. 

All the brakes were tested with a 180mm rotor and a 50Nm force on the lever (1N is the amount of force required to accelerate 1kg at 1m/s2), with the stock pads. To fully bed in the rotors and pads, the brakes were given 60 one-second pulls at 15km/h, followed by 30 two-second pulls at 20km/h. After a 30-second cooling-down period, the testing began. 

With the wheel spinning at 30km/h, each brake was applied for three seconds and then left to recover for 10 seconds. This cycle was repeated 15 times. The results were then averaged out to provide a single power rating, which you can view below. (Weights are calculated including 180/183mm rotors, post mount kit and rotor bolts.)

Power ratings (in alphabetical order)

Brake model Power (Nm) Weight (g)
Ashima PCB 64Nm 328g
Avid Code R 103Nm 429g
Avid Elixir 1 100Nm 471g
Avid Elixir 3 100Nm 442g
Avid Elixir 7 99Nm 395g
Avid Elixir 9 99Nm 397g
Avid XX WC 90Nm 356g
Formula R1 107Nm 355g
Formula R1 Racing 104Nm 334g
Formula RO 124Nm 418g
Formula RX 107Nm 398g
Formula The One 121Nm 393g
Gusset Chute 89Nm 469g
Hayes Prime Pro 90Nm 501g
Hope Race Evo M4 115Nm 496g
Hope Tech Evo V2 120Nm 524g
Hope Tech Evo X2 97Nm 463g
Hope X2 Race Evo 110Nm 377g
Magura MT2 103Nm 428g
Magura MT6 103Nm 337g
Magura MT8 90Nm 339g
Quad QHD-7 Nano 97Nm 463g
Quad QHD-7.1 Nano Light 92Nm 422g
Quad Rapide 97Nm 475g
TRP Dash 85Nm 407g
TRP Dash Carbon 85Nm 393g
Tektro Auriga Pro 77Nm 491g
Shimano Deore M596  104Nm 490g
Shimano SLX M666 111Nm 485g
Shimano Saint 105Nm 529g
Shimano XT M785  107Nm 466g
Shimano XTR Race M985 110Nm 388g
Shimano XTR Trail M988 112Nm 407g

Power ratings (in ascending order of power)

Brake model Power (Nm) Weight (g)
Ashima PCB 64 328
Tektro Auriga Pro 77 491
TRP Dash 85 407
TRP Dash Carbon 85 393
Gusset Chute 89 469
Hayes Prime Pro 90 501
Avid XX WC 90 356
Magura MT8 90 339
Quad QHD-7.1 Nano Light 92 422
Quad Rapide 97 475
Hope Tech Evo X2 97 463
Quad QHD-7 Nano 97 463
Avid Elixir 9 99 397
Avid Elixir 7 99 395
Avid Elixir 1 100 471
Avid Elixir 3 100 442
Avid Code R 103 429
Magura MT2 103 428
Magura MT6 103 337
Shimano Deore M596  104 490
Formula R1 Racing 104 334
Shimano Saint 105 529
Shimano XT M785  107 466
Formula RX 107 398
Formula R1 107 355
Shimano XTR Race M985  110 388
Hope X2 Race Evo 110 377
Shimano SLX M666 111 485
Shimano XTR Trail M988 112 407
Hope Race Evo M4 115 496
Hope Tech Evo V2 120 524
Formula The One 121 393
Formula RO 124 418

What we found out

We've tested a range of brakes this year, from medium powered, medium weight trail brakes to heavier-duty high-power all-mountain/downhill brakes. We’ve also covered a wide price range from £100 to £300-plus. The good news is that there are loads of simple, reliable and powerful brakes for £100 and below. 

As you head towards £150, features such as bite point and leverage adjust start to appear (for explanations of these features see our Buyer's guide to disc brakes). Towards £200 carbon fibre levers, multi-cylinder callipers and the differences between specifically powerful, tough or lighter specialist brakes appear. Beyond £200 you can expect the absolute top stopping technology depending on your priorities. At any price, choosing a brake available in separate parts makes sense if you’ve already got rotors and mounts. 

While functionality or range of features should increase with price, interestingly – or perhaps irritatingly – reliability generally doesn’t. The good news is that there are few really ropey brakes in terms of reliability, but complexity is often the enemy of consistent performance. Some brands need more careful TLC than others on the trail or in the workshop. As working brakes are crucial for safe and confident riding it makes sense to choose a unit that suits your preferred level of servicing and skills with an Allen key and bleed syringe.

Once you’ve got a suitable price and reliability shortlist, apply your riding preferences. If you’re a heavy rider, or just heavy on your brakes, then more power is an advantage. If you regularly ride proper mountains, choose brakes that mean less arm pump and can cope with prolonged pulls without fading or boiling. Don’t think that because your favourite pro uses them they’ll suit you though. Most of the fastest riders hardly use their brakes – which is why they’re fastest. Being able to control your brakes' power very finely in slippery conditions is more important than absolute anchorage. 

Finally think about your personal braking preferences. Some brakes feel very solid under your fingers, others have a softer, squeezy feel. Some apply power progressively, others stop you like a branch through your spokes. Being able to adjust bite point or having a specifi clever feel/ shape might be vital to you, or maybe colour customisation is your thing.

Reviews

Reviews of all the brakes in this article are split across issue 132 of What Mountain Bike magazine (March 2012), out now, and issue 275 of Mountain Biking UK (April 2012), due in shops on 7 March. They'll appear here on BikeRadar in due course. For more help with buying hydraulic discs, check out our Buyer's guide to disc brakes.

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