Along time, bicycles have evolved and along with them, the braking system. The beggining took the shape of the rod fitted with a piece of rubber at its end that pressed directly on the wheel, while evolution took the brakes to the modern sofisticated hydraulic models, that feature even assistence almost like an ABS. We will describe in this article the most common brake types, where to use them, pros and cons for every type, categorised by the work mechanism.
This system was probably invented after some bicycle riders realised that braking with your feet doesn’t always do the trick. At first, the spoon-style brake was simply a piece of metal pressing on the tire, being wide-spread in the times of the solid rubber tire. Afterwards, its end got a rubber piece in order to avoid tear, and you can still find this model nowadays on bicycles put up for sale at cheap prices, usually in developing countries.
Advantages> no-brainer mechanism
Disadvantages> low stopping power, high wear of the front tire
This type of brake is included in the rear hub and works by simply pedalling backwards. Having a high efficiency, it is wide-spread and probably the most common type of brake fitted on regular single-speed city bicycles, although it is also paired up with internal gear hubs.
Advantages> easy to use, highly efficient, requires low-maintenance
Disadvantages> you might accidentally use it, avergae braking power, doesn’t allow mutiple sprockets
We remain in the single-speed zone, with brakes tucked in the hub and we stop for the drum brake. In this case, we can see a model inspired by the way car brakes work, with calipers that press from the inside out. It requires virtually no maintenance, still stopping power fails to deliver. As opposed to the coaster brake, it’s set in motion by a lever on the handlebar.
Advantages> easy to use, requires low-maintenance
Disadvantages> average braking power at best
For a long time, the rim brakes have been the most popular choice for all the types of bicycles. Braking is done via a pair of pads made from rubber or other materials that press on the rim’s side, regardless if the rim is of carbon or alloy. Further, rim brakes divide into several large categories, each with an inclination for a certain type of usage. The main two sub-types are the rim brakes that use a single mounting point and those which use two, while some other types have been manufactured, but remained in a niche.
Double lateral mount rim brakes
One of the first rim brake ever to feature on a bike was the cantilever. Having a simple functioning mechanism, it is composed out of two pivoting arms and a cable that ties them. A hanger at the end of the braking cable grips the connecting cable, so when the lever is pulled, the hangers engages the two pivoting arms in a motion via the connecting cable.
This type of brake got popular when mountain bikes started flooding the market, so its hayday passed. Only cyclocross, city and low end bikes still feature this type, but even the first two categories of bikes are starting to have disc brakes.
Advantages> simple design, generous clearance, mud doesn’t interfere, can be used with road brake levers
Disadvantages> average braking power, hard to set-up
They have been a great hit amongst breaking options and eventhough they belong to another era, their advantages kept them in the top of choices. The secret lies in the fact that they improved the principle of the cantilever, lengthening the pivoting arms in order to get more leverage and placing the connecting cable parallel to the ground.
This enabled developing very efficient models, like Shimano’s parallelogram models, which were up until recently wide-spread. The V-brake was the flag-ship type of brake for mountain bikes until disc brakes started to become a standard solution. One key-difference versus cantilever brakes resides in the fact that V-brakes need their special lever, because the travel is longer. For instance, a road bike braking lever cannot be used.
Advantages> great braking power, excellent modulation, easy to set-up
Unlike the other type of brakes presented so far, which need two mounting points and are composed out of two pieces, the U-brake is a single-piece part. Also, it has been present for decades and retained its shape and working principle. From the very beggining, road and city bikes were the ones using them, a thing that hasn’t seen much change.
Versions destined for city bikes remained mostly unchanged, with a wide clearance, while the ones meant for road bikes evolved along with them, becoming more compact, more aerodynamic and more light, the top-end models weighing cca. 100 grams/caliper. Using state of the art materials, they also feature high stiffness and wind-cheating shapes. They work just fine for alloy and carbon rims alike, a simple switch of pads being enough to make them compatible with one type or another.
Working principles have not changed, but they have developed in the single and double-pivot sense. The latter brake faster and stronger, and some manufacturers use the single pivot for the rear wheel, and the double for the front wheel.
Mounting also saw some change from the moment the direct mount system stepped onto the scene, with its two screws that hold the caliper in place. Eventually, the placing of the brake reached the underside of the bottom bracket, which left the seatstay unocuppied and a good subject for tampering in order to increase vertical compliance.
Eventhough similar, the road bike U-brakes and city bike U-brakes involve different levers.
Usage> road bike, city bikes, BMX
Advantages> great braking power, low weight, aerodynamic
Disadvantages> mud and water sensitive, faulty modulation
Hydraulic rim brakes
Not very wide-spread, the hydraulic rim brake has its own special place in the heart of bike lovers. One model that came to represent this product is Magura’s HS, which at first looks like a cantilever brake, and has a piston in each caliper that presses the pads against the rim. One hose runs from the lever to one of the calipers, while another hose connect the two calipers and distributes evenly the hydraulic fluid. Manufacturers found city bikes appealing for this sort of brakes, but also some models of mountain bikes and trial bikes have featured them.
Advantages> fantastic braking power, require virtually no maintanance
Disadvantages> moisture sensitive, rim wear
Disc brakes represent the pinnacle of braking currently. They rely on a caliper that includes two brake pads that squeeze the rotor attached to the wheel’s hub. It comprises a lot of pros, from which we underline the following
- Excellent braking power
- Precise modulation that allows applying exactly the amount of braking power the rider desires
- Great reliability
- Good functioning in all weather conditions
- No rim wear
Setting you back when using disc brakes is their weight. Also, some voices point to the hazard in terms of injury of the disc brakes, eventhough extensive testing has not been made, so there is no conclusive evidence in this sense. According to the mechanism the rely on, disc brakes can be hydraulical or mechanical
Mechanical disc brakes
Like rim brakes, they employ a steel cable that pulls the brake pads from the caliper. While the mechanism is simple, it’s not very reliable, having the typical issues like wear, oxidation, jamming etc. The elasticity of the cable induces losses in terms of power.
Inside the caliper, the cable triggers a set of levers that brings one pad closer to the rotor until the pad presses the rotor against the other pad. This happens in the case of low-end models, while the mid-level and high-end models have both pads travelling.
Mechanical disc brakes are present on mountain bikes as well as on road and cyclocross bikes. As you might have presumed by now, the first use a certain type of brake levers, while the last two a different one. Also, one should take note of the fact that wear of the pads is not equal, which means that in time, adjusting the brake might be needed.
Usage> all types of bikes
Advantages> low price, simple, easy to fix
Disadvantages> loss of braking power, low reliability, unequal wear of the pads
Hydraulic disc brakes
Representing the pinnacle of engineering, almost all types of bikes have hydraulic disc brakes, and probably in the coming years, they will be present on all the types of bikes, judging by how things are going.
Inside the caliper, the brake pads adjust themselves as they wear off. Brakes made for extreme riding have even two pistons for one pad, in order to provide extra stopping power. Reliability is at home with this system, eventhough the pistons tend to jam from time to time if they are exposed to mud or humid conditions, but it’s a thing that a bike service can easily fix.
Usage> all types of bikes
Advantages> fantastic braking power, sensitive modulation
According to their destination, rotors vary in diameter. The sizes include versions of 140, 160, 180 and 203mm, the braking power and weight increasing along with the size. If 140mm rotors are for cross-country racing, 203mm rotors fit the bikes that run downhill.
Some manufacturers developed special iterations, like Shimano in the case of Ice Technology, that have an aluminum core, while other models feature extra fans in order to increase air flow and thus cool down the rotor faster. Other manufacturers went for the floating rotor, which implies a slight lateral movement of the rotor in order to better fall into place between the pads when braking.
As for the mounting part, all manufacturers except Shimano use the IS 6-bolt standard, while the Japanese brand developed its own technology, named CenterLock, which is stiffer and easier to mount, having the same system as the cassette. The 6-bolt rotors can be mounted on CenterLock hubs using an adapter, but CenterLock rotors only work with Shimano hubs.
Cross-country mountain bikes usually use 160mm rotors, but some models feature 180mm or 140mm ones, either for better braking, either for shaving off as many grams as possible.
Trail and enduro mountain bikes have larger rotors, at least of 180mm, and a few cases include 160mm rear-brake rotors. Often one can find 4-piston calipers, for one or for both wheels.
Downhill and freeride bicycles come with 203mm rotors, since stopping power is esential. The previous 4-piston calipers are present here as well.
City bikes tend to have 160mm rotors.
In order to attach the calipers to the frame of the bicycle, several mount standards are currently in use – IS, PM and Direct Mount. They are not compatible between themselves and it’s compulsory to use the requested standard, place the caliper in the designated position and even use longer screws when needed. For rotors exceeding 160mm, adaptors will be used, and it is quite important to know that screws that are too short may damage the mount thread. Below you can see the IS, PM and Flat Mount, in order.
Also, you might want to consider the fact that frames are designed for a certain rotor size, and this information needs to be checked in order to ensure proper functioning.
The shape and size of brake pads doesn’t differ, but only the material they are made of. Resin is used for cheaper brake pads, which offer good and silent braking performance, but last lesser, especially in wet conditions. Further, there are the full metal or half-metal pads which tend to be louder and less generous in terms of braking performance, but which last longer even in mud or wet conditions. Choosing the right pad is up to each and everyone, though some rotors work better with certain pads.
Some manufacturers include in their range pads with cooling fans or alloy core, in order to prevent all the heat reaching the caliper and influencing the brake liquid. It is a gain in terms of performance, eventhough marginal.
Regardless of brake type, be sure it is in proper working condition and if it needs replacing various parts, then do this right away. A worn-out braking system will put your life in peril and can cause serious injuries.