They say that in life, “All good things come to those who wait” – the perfect pint or that perfect sunset. But when you’re charging hard into a corner, roost flying, eyes on stalks and breathing hard, when you pull the brakes you want instant action!

A good disc brake does more than just slow you down; it allows you to dance that fine line between traction and skidding. It will have enough power to pull your E-MTB down from speed but still have smooth modulation, allowing you to feel exactly how much force the tires can handle. Finally, a good brake will be easy to bleed, without drips, so you won’t get in trouble for covering the family pet in DOT 5.1.

Anatomy of a good brake

Bleeding systems
What marks out the best brakes is a bleeding process that does not involve wiping brake fluid off the ceiling at the end.

Clamp
Most brakes now come with a split clamp, allowing them to be removed without removing grips. Many brands now provide direct mounts for shifters to minimise clutter on the bars.

Contact Point Adjustment
You choose exactly where in the lever travel you want the bite point (the point where the pads touch the rotor and start decelerating) to be.

Fade
When the pads and rotors get really hot under extreme use (over 500oC), the resin used to bind the pad compounds together starts to boil, producing gas that reduces friction between the pad and the rotor.

Fluid
Many brake brands now use mineral oil for the hydraulic fluid, which is a less toxic alternative to DOT fluid. DOT, however, is cheap and readily available.

Reach Adjustment
Reach adjustment allows you to move the lever start point in and out from the bar. Some models offer a tool-less control, while others need a Torx key or other tool.

Lever ergonomics
Your main point of contact with the brakes is the lever. The best brakes now have a pivot that runs on ball bearings to ensure smooth and play-free action.

Modulation
Modulation is defined as how easy it is to control the amount of force acting through the brake. The best levers feature special cams which change the amount of leverage exerted during each phase of travel, improving modulation and control.

Pad type
Most brakes are fitted with, or have the option of, organic or sintered pads. Organic pads offer a more powerful bite and generally quieter operation, but are more prone to fade during long, hot descents. Sintered pads are much more resistant to heat build-up, but are generally not as powerful as organics.

Pistons
Brakes work by squeezing the pad between opposing pistons, and most calipers now feature two or four pistons. Four-piston brakes are heavier, but generally offer more modulation and are best for E-MTBs

Rotor Size
The most cost-effective way of improving braking performance is to increase the rotor size; increasing a rotor’s diameter can result in up to a thirty-percent improvement in performance and modulation through improved heat dissipation.

Overview

Brake Adjustment Weight (just one) Price (just one)
Hope Tech 3 E4 Reach Adjustment, Contact Point Adjustment 252 g € 214.10
Magura MT4 Reach Adjustment* 212 g € 89
Magura MT5 Reach Adjustment* 248 g € 111
SRAM Guide Ultimate Reach Adjustment, Contact Point Adjustment 230 g € 301
SRAM Guide RE // Reach Adjustment 274 g € 145
Shimano Saint Reach Adjustment, Contact Point Adjustment 300 g
Shimano Deore XT Reach Adjustment, Contact Point Adjustment* (does not work) 278 g
Shimano XTR Reach Adjustment, Contact Point Adjustment* (does not work) 256 g

PS: Readers' Survey 2017 - Give feedback, win awesome prizes: We're giving away prizes worth more than €20,000 among all participants of our reader's survey! Win E-MTBs from Focus, Moustache and Thömus and more! Click here to take part now!

About the author

Trev Worsey