All disc brakes, whether hydraulic or mechanical, work the same way, slowing or stopping the bike by pressing the two disc brake pads against the edges of the rotor.
However, as with most things in cycling, there are options for even seemingly simple consumables like disc brake pads.
Your bike’s pads wear out over time, so you need to check your pads regularly for wear before replacing them.
If you are not satisfied with the braking performance, you can also replace and upgrade the brake pads, different brake pads are better for different conditions.
But what kind of disc brake pads do you need for your bike? Everything you need to know is here, including how disc brake pads work, when to replace disc brake pads, and the various materials available.
Mountain bike disc brakes have long been commonplace, but in recent years disc brakes have also become the de facto standard for road and gravel bikes.
As a result, disc brakes are the most common type of bicycle brake on the latest performance-focused machines. But how do they work?
Disc brake pads consist of a piece of brake material glued to a metal backing plate. The metal plate stiffens the brake surface structure and holds it inside the caliper.
When you apply the bike’s brakes, the pistons in the calipers press the brake pads against spinning rotors that are attached to the wheel hub.
There is usually a metal spring to prevent the pads from rattling in the caliper when the brakes are not applied, although some designs, such as the Magura MT 7 mountain bike disc brake, use magnetic pads and pistons and omit the spring.
The friction between the pads and the rotors generates heat and also slowly wears down the layers of brake material in the pads.
Metal plates help dissipate heat from the brakes, and some have fins or other features to help dissipate heat faster.
During prolonged hard braking, the brake pads can transfer enough heat to the calipers to boil the hydraulic fluid in the pistons, causing the brakes to fade and reduce braking efficiency.
As a general rule, you should replace disc brake pads when the thickness of the brake material layer is 1.5mm or less.
The speed at which this happens depends on the type and conditions of riding, as well as the composition of the brake material.
In wet and muddy conditions, the pads wear out much faster than in dry conditions – you may even need to carry replacement kits with you on particularly long trips and replace them in the middle of a trip. In dry conditions, you can get longer life from a set of pads.
More extreme riding, such as downhill mountain biking, wears out pads faster than full trail mountain biking or normal highway riding.
If they are not properly aligned with the rotors, you may also experience uneven wear – or they may rub against the rotors when not in use. We have a separate article on brake pad alignment and how to stop disc brake friction, as well as a guide on how to replace disc brake pads.
When it comes to brake pad wear, you definitely shouldn’t go all the way to metal-to-metal contact between the pad holder and the rotor, as this will not only degrade braking performance, but will quickly damage the rotor.
Like many bicycle components, disc brake pads come in many shapes and sizes to fit different brake models, so the trendy answer is “the ones that fit your brakes”.
But there are many more options for overlays, as overlays can be made from a variety of materials. The best option for you depends on the type of riding you do.
Pads can be organic, sintered, or semi-metallic, and we’ll look at their pros and cons.
Organic disc brake pads are usually made from Kevlar, rubber and silica and bonded together with resin.
If noisy brakes annoy you, organic brake pads are for you. Also known as resin pads, they are the quietest option. They also give you more responsive braking and don’t require warm-up before they start working properly.
The organic compounds help insulate the brake pads from the calipers, so more heat stays in the rotors and less heat is transferred to the brake fluid, although they are more prone to fading under prolonged braking.
Organic pads also wear out faster than other options, so you’ll need to replace your pads more often. They also don’t like muddy or slippery rides, and they can be glazed so you may need to fix the pads.
Organic brake pads are a good option for less extreme riding in dry conditions, so they are great for summer use on road bikes and XC mountain bikes with disc brakes, especially if you live in relatively flat terrain and don’t lose riding technique with a lot of braking.
They are more durable and last longer than organic mats because they handle dirt and wet conditions better.
Sintered pads also handle higher temperatures well, although metal components tend to transfer more brake fluid heat in the calipers than organic pads.
However, sintered brake pads take some time to warm up before they perform at their best, and are also more prone to noise.
If you ride in more extreme conditions (like if you ride downhill or enduro bikes) or if you ride in mud a lot, sintered disc brake pads are a good choice.
Other benefits include better stopping power than organic pads on long descents and faster warm-up than sintering.
Like organic mats, they are easy to glaze and are usually the most expensive option. They are also not as quiet as organic pads.
They are a great all-around option for road racers and XC mountain bikers as they perform well in wet or dry conditions without sacrificing a lot of life.
It’s worth experimenting with pads and pad combinations rather than just swapping like for like.
You can also swap pads between summer and winter, opting for organic pads for extra power and quieter operation in summer and sintered pads for durability in winter.
You can also mix and match lasts using durable sintered or semi-metal lasts on the back and organic lasts on the front.
An organic front pad will give you more stopping power, but at the cost of more wear. The rear brake doesn’t need to have the same stopping power as the front, and stiffer pads need to be stronger and more weather resistant.
For best results, when changing the pad compound, the disc should also be replaced, as the new pads will not adhere well to the layers of material on which the pads were laid.
Still, keeping the same rotors wouldn’t have been a disaster – it just took the new pads longer to set.
The backing material used on the brake pads also deserves attention. You may not have a choice, but some brands make pads with alloy or steel backing – the former can save you a few grams and sometimes promise better heat dissipation.
Titanium pads are also available, most notably the Shimano XTR brakes, again reinforced.
Disc brake pads with integrated cooling fins are also becoming more common, popularized by Shimano with their Ice-Tech pads, which are said to improve braking performance by using airflow to quickly remove heat from the pad surface.
Paul has been writing about cycling technology and reviewing all things cycling for nearly a decade. He worked for Cycling Weekly for five years and has written for magazines such as CyclingNews, Cyclist and BikePerfect, and also writes regularly for BikeRadar. On the technical side, it covers everything from rim width to the latest bike computers. He reviewed some of the early e-bikes for Cycling Weekly and turned them into the complex machines they are today and gradually became an expert in all things electric. Paul fell in love with gravel before it was even invented, riding his SUV down the South Downs and on dirt trails through the Chilterns. He has also tried off-road mountain biking. He is most proud of having completed the South Downs Way on an off-road motorcycle and fulfilled his longtime ambition to climb Mount Grappa on a road bike.
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Post time: Nov-05-2022