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 modelPower (Nm)Weight (g)
Ashima PCB64Nm328g
Avid Code R103Nm429g
Avid Elixir 1100Nm471g
Avid Elixir 3100Nm442g
Avid Elixir 799Nm395g
Avid Elixir 999Nm397g
Avid XX WC90Nm356g
Formula R1107Nm355g
Formula R1 Racing104Nm334g
Formula RO124Nm418g
Formula RX107Nm398g
Formula The One121Nm393g
Gusset Chute89Nm469g
Hayes Prime Pro90Nm501g
Hope Race Evo M4115Nm496g
Hope Tech Evo V2120Nm524g
Hope Tech Evo X297Nm463g
Hope X2 Race Evo110Nm377g
Magura MT2103Nm428g
Magura MT6103Nm337g
Magura MT890Nm339g
Quad QHD-7 Nano97Nm463g
Quad QHD-7.1 Nano Light92Nm422g
Quad Rapide97Nm475g
TRP Dash85Nm407g
TRP Dash Carbon85Nm393g
Tektro Auriga Pro77Nm491g
Shimano Deore M596 104Nm490g
Shimano SLX M666111Nm485g
Shimano Saint105Nm529g
Shimano XT M785 107Nm466g
Shimano XTR Race M985110Nm388g
Shimano XTR Trail M988112Nm407g

Power ratings (in ascending order of power)

Brake modelPower (Nm)Weight (g)
Ashima PCB64328
Tektro Auriga Pro77491
TRP Dash85407
TRP Dash Carbon85393
Gusset Chute89469
Hayes Prime Pro90501
Avid XX WC90356
Magura MT890339
Quad QHD-7.1 Nano Light92422
Quad Rapide97475
Hope Tech Evo X297463
Quad QHD-7 Nano97463
Avid Elixir 999397
Avid Elixir 799395
Avid Elixir 1100471
Avid Elixir 3100442
Avid Code R103429
Magura MT2103428
Magura MT6103337
Shimano Deore M596 104490
Formula R1 Racing104334
Shimano Saint105529
Shimano XT M785 107466
Formula RX107398
Formula R1107355
Shimano XTR Race M985 110388
Hope X2 Race Evo110377
Shimano SLX M666111485
Shimano XTR Trail M988112407
Hope Race Evo M4115496
Hope Tech Evo V2120524
Formula The One121393
Formula RO124418

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.

Guy Kesteven
Author: Guy Kesteven

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