Disc brakes

Good disc brakes let you shave off speed so you can keep riding smooth and fast, safe in the knowledge that instant stopping power is a finger-flex away; we put 10 of the latest to the test

- Paul Burwell

Power is nothing without control, but ideally a mountain bike disc brake has both. And while it’s easy to think that your brakes are primarily for stopping, most of the time you actually use them to control your speed. In fact, the only time you really need to stop dead is at the end of a ride or the bottom of a descent – the rest of the time you just want to control speed. Disc brakes still need to be powerful though, because that allows you to brake with one finger, which reduces fatigue and gives you a better grip on the handlebar, improving safety and control.

One of the main ways manufacturers are able to increase power is by running larger-diameter rotors and four-piston calipers. Using four smaller pistons rather than two big ones means the pistons push against more of the brake pad, increasing pressure at the rotor. They can also be set up so that one set of pistons contacts the rotor before the second, which can help modulation. On the other hand, more pistons can equal more weight and more complexity, which means a higher price tag.

Recent improvements in brake performance have gone hand-in-hand with the increased capability of most bikes – we’re now riding harder and faster, so controlling that increase in speed requires a more powerful brake. E-bikes have also placed greater demands on braking systems, as there’s more mass to slow down. Which is why rotors now go up to 225mm in diameter and there are so many more four-piston options on the market.

New tech has driven prices up, but we’ve also seen a lot of it trickle down to the low end. Also, you really don’t need to spend £700 on a set of lightweight disc brakes for a 22kg e-bike when a budget brake, using the same pads and rotors, does the job just as well.