Which hydraulic disc brakes

By James Bracey TZ. As with all aspects of modern life, the humble bicycle has had more and more revolutionary ideas thrust upon it in the last few years than ever before. We are now used to electronic and wireless shifting from SRAM Red eTap that reliably works, before anyone mentions Mavic Zap , sub gram carbon frames, 3D printed components and of course, disc brakes.

Once the reserve of the mountain bike, disc brakes have been steadily rising in numbers within the road community. When Giant unveiled its new range of Defy carbon endurance bikes for not a single rim brake was to be seen, and the same is the case with the new BMC Roadmachine.

Expect to see more manufacturers following suit, already most of the high profile brands offer disc brake incarnations of their top-end offerings. Yet, in a similar way to the age-old Shimano versus Campagnolo debate, for every rider pro disc there are equal numbers vehemently anti-disc technology. Uncertainty may surround the future of the technology in the professional sport however the fact remains that the disc brake option will likely be high on the list of consideration for all of us for our next purchase.

The key thing is to be properly informed so you can choose the right option to suit your needs. All bicycle brakes are designed to push a friction-creating brake pad against a braking surface on the revolving wheel by way of a hand-operated lever. As pressure is increased at the brake lever the friction force is increased.

The difference between rim and disc brakes is where and how the braking force is applied in relation to the wheel of a bicycle.

Traditional rim brakes, as their name implies, base the braking force on the outer edge of the wheel. A disc brake focuses forces on a smaller rotor, situated towards the centre of the wheel. Disc brakes generate an incredible amount of stopping power, usually far more than is necessary to adequately stop a road bicycle. This allows the rider to apply much less force to the lever before the bike comes to a halt.

Less hand strength leads to a decrease in muscle fatigue, especially on longer descents. Disc brake power can also be customised by exchanging the disc rotor the metal braking surface for rotors of differing diameters.

A larger rotor equates to more powerful brake, useful for larger riders or heavier bikes. Pulling with a specific amount of strength on the brake lever of a rim brake can result in wildly inconsistent results. When you pull on a disc brake equipped lever, resultant braking force is much more consistent. This reliability allows you to accurately judge how much force you need to apply in order to achieve the expected result.

So despite it being easier to lock up a wheel with a disc brake, the feedback at the lever means you are far less likely to do so. When you apply a rim brake in wet weather there can be a split second delay before you start decelerating. This delay is due to the brake pad displacing water and road grime from the rim to enable sufficient contact and friction.

As such the actual braking force you apply in the dry might not stop you in the wet. If you have carbon rims, it might require the strength of Schwarzenegger himself to bring you to a halt. Although not all disc brakes function in the same way, the advantages described above are to a greater extent accurate for all disc brakes. At a very basic level they all feature pistons that push either one or both brake pads onto the rotor.

The differences come with the way that lever force is transferred to the calliper and brake rotor. At one end of the spectrum we have cable actuated brakes, sometimes referred to as mechanical disc brakes.

These function in much the same way as a rim brake, relying on a braided steel cable to move the pistons. The upside of this design is it works in conjunction with your normal, rim brake compatible shifters. Just like rim brakes, they can suffer from cable contamination and are on the whole notoriously fiddly to set up perfectly without rubbing.

In contrast hydraulic disc brakes use a sealed, fluid filled system as the means of actuation. While this is a brake packed full of features, and promises easy setup, it does come with a high price. An evolution of the good old Hope Mini brake, the X2 was designed to take all the performance of that well-known stopper and shave off a few more grams. The Tech 3 lever is excellent, with bite point and reach adjusted easily via large glove-friendly dials. Fitting and adjustment are simple too, with a rotating banjo-shaped hose attachment and top-entry pads making maintenance a breeze.

The brake has two pistons housed in a CNC-machined caliper. Built for gravity-orientated and electric bikes, these four-piston Magura MT5 brakes provide heaps of power and easy modulation. In the caliper, the four pistons press onto one pad, and once bedded in, this system provides plenty of grunt, particularly towards the end of the brake stroke, which is perfect for riding on steep terrain.

Magura offers a range of levers with these brakes and in testing we had the two-finger levers, which exhibited a plasticky feel and flexed slightly. The brakes had a spongier feel than others, but this could be down to the extra length and flex at the lever.

When it comes to maintenance, bleeding the brakes is easy and the long hoses should fit almost all bikes. Changing the pads requires removing the wheel and there is a knack to it. The Magura MT Trail SL differs from other trail and enduro brakes by having a four-piston front caliper and a two-piston rear caliper.

The front caliper provides the high braking power and modulation you need for top-level performance, while fewer pistons on the rear caliper helps save weight. The lever has a flip-flop design and reach adjustment and Magura offers different lever blade types, which can alter the interface between finger and brake. The single-finger design we tested gave a reasonably sharp initial bite and in the mid-stroke it offered plenty of modulation.

The lever itself is 70mm long with no flex, making the brakes feel assured and firm. The four-piston calipers provide excellent stopping power, even on heavier electric bikes. Pair this with the lever feel and these brakes are super-positive, engaging power almost instantly, and giving that trademark Shimano brake feel.

Arguably, this makes applying power with finesse harder than other brakes, but it does give you plenty of confidence that things are working as they should.

However, getting the right bleed is critical to the performance of these brakes. The 80mm carbon lever has a smooth, contoured shape. The lever provides lots of control, making it easy to correct speed on faster sections or apply a load of stopping power when needed. This might make the premium price tag hard to justify for some, but it might also point to just how good SRAM Code brakes and others truly are.

Cross-country mountain bikes might come with mm rotors, trail bikes with mm and downhill bikes with mm rotors, but rotor sizes extend above the mm mark too. Some riders opt to use a mix of rotor sizes, with a larger rotor on the front for greater braking force and a smaller one on the rear to save weight. It used to be that only gravity riders would consider four-piston calipers — known as four-pot brakes — and everyone else would stick to two-piston calipers, known as two-pot brakes.

Of course, two-piston brakes still have acres of power on hand. Most brakes offer reach adjustment, which allows you to set the lever distance from the bar to suit your hand size. Some offer bite point or free stroke adjustment too, varying the amount of lever-free travel before the pad connects with the rotor.

This can be either tool-free or tool-driven. Most disc brake pads are organic pads made of resin, glass, rubber and other non-metallic materials. If pads are removable from the top of the caliper, they can be cleaned or replaced without the hassle of removing the wheel first.

Hydraulic brakes use mineral oil or DOT fluid to drive their pistons. Well for starters, you have to keep in mind how you will be using your e-bike. When purchasing a bike you want to make sure that it is equipped with brakes that you feel that you can trust. It is important to know the difference between mechanical vs. Brakes are an important part of your bicycle just like they are for a car. Typically those who purchase an e-bike will be using it more than those who don't own an e-bike.

So what exactly are Hydraulic brakes? What is the difference between mechanical vs. To begin with, hydraulic brakes refers to when the brake lever is pulled a fluid is being compressed which then will run all the way down to the brake caliper.

After this is done the brake pad is compressed to the wheels rim. With hydraulic brakes there is no brake cable involved in the process. Mechanical refers to when you pull the brake lever the brake cable is being pulled, which in return pulls the brake caliper that essentially pulls the brake pads into the rim.

Note that with mechanical there is no fluid involved making this a big difference between both. So you may ask yourself which one is better? The answer as stated above is what you feel most comfortable in.