The operating principle of rim brakes is extremely simple. On the bicycle handlebar there is a brake lever, from which a special cable (or a hydraulic line is laid) is pulled to the brake pads located on both sides of the bicycle wheel rim. When the handle is pressed, the rim is compressed by the pads, after which the wheel rotation slows down and comes to naught.
There are two types of rim brakes, which in turn are subdivided into several subtypes:
- Mechanical brakes including:
- vector (V-brake or “vibrake”) with V-shaped attachment of the levers to the brake pads;
- tick-borne (“crabs”) with U-shaped levers;
- and cantilever (obsolete predecessors of V-brakes).
- Hydraulic brakes, in which the applied force is transmitted from the handle to the pads by the brake fluid along a specially laid hydraulic mowing line.
Rim brakes have a number of clear advantages over other types of bicycle brakes:
- Low loads on bushings and spokes.
- Less braking heat.
- Easy setup even in the field.
- Low weight of the actual brake.
- Not a high price at all.
Replacing rim brake pads on a bicycle
Over time, rim pads (like any other bike part) fail. And any self-respecting bike enthusiast, not to mention professionals, should be able to replace them. over, this is easy to do with v-brakes. The main thing is to do everything slowly, clearly observing the technological stages in the required sequence:
- Open the brake. bring its levers together and remove the iron tip of the “shirt” from the groove formed (the cable comes out of it).
- Remove old pads, remembering in which sequence the fasteners were used.
- Install new pads, sequentially collecting all fastening washers and washers.
How To Replace Rim Brake Pads | GCN Tech Basic Road Bike Maintenance
It’s even easier when it comes to cartridge pads! It is only necessary to replace the rubber gaskets. remove the retaining cotter pin, remove the old one and put a new gasket, and then secure it with the same (or new) cotter pin.
Care must be taken when changing v-brake pads as they can be left or right (the markings are directly on the pads). Then they should never be confused.
In addition, it is not enough just to change the pads, you also need to adjust them. And before that, check the brake cable for wear or breakage. He must be absolutely intact and easily move around in a “shirt”. It is also necessary to check the shape of the wheels so that there are no “eights”.
The brake pads must be properly pressed against the wheel rim. And the pressure can be adjusted (configured) with the shoe mount. It is not difficult to get the desired angle if you hold down the brake and loosen the nut on each of the pads.
The v-brake cartridge pads should be located strictly horizontally, touching their entire surface to the rim, but not touching the tire. And when the required position is reached, you should fix it with a shoe nut. Regarding conventional brake pads, the rear of the pads must first come into contact with the rim horizontally.
During the tuning process, it is also necessary to ensure that the brake levers come together equally. Position adjustment is possible with a Phillips spring tension screw. If the lever barely moves, then the screw should be tightened, and when the lever moves too easily, unscrew.
Replacing brake pads on a bicycle
Both avid cyclists and novice amateurs have to deal with the need to replace brake pads on bicycle transport. And practice shows that the more you pedal, the more often you should change the brake pads.
A bicycle disc brake is a combination of a steel disc (rotor) located on a hub with a caliper. a device that actually clamps the disc with the brake pads. From the brake lever on the handlebar, the force is transmitted to the brake by a cable (mechanical disc brake type) or through a hydraulic mowing line (hydraulic disc brakes).
Bicycle disc brakes also have their advantages. They are:
- less clogging when driving;
- can work without problems while driving on snow or mud;
- as smoothly as possible (in contrast to rims) adjust the braking force;
- do not react to slightly curved wheel geometry (small “eights” are not a hindrance for them);
- do not affect the wear of the rim;
- and do not require expensive maintenance.
Many bicycle disc brakes have only one moveable brake pad. The second is fixed statically relative to the frame structure. This greatly simplifies and reduces the cost of the caliper. But, however, as the wear and tear, the cyclist will have to tighten the brake pad, which is stationary.
Brake discs are standard sizes. These are 140, 160, 180, 185, 203 or 220 millimeters.
It is the bicycle brakes that are responsible for regulating the speed of driving on a two-wheeled vehicle and, in particular, for slowing down the speed of movement, as well as stopping. They can be of several types:
The most common ones used in most modern bike models are disc brakes and rim brakes.
Replacing disc brake pads
There is a step-by-step guide to replacing worn-out disc brake pads:
- First you need to remove the caliper and clean it if necessary.
- Then remove the retaining ring or wiring so that the bolt does not unscrew.
- Remove the boot (twist or snap, depending on the model). And if the bolt is dirty, then it must also be cleaned.
- Remove old bicycle brake pads. Sometimes they can be easily removed, and in some models they need to be pryed off-tucked a little, freeing them from the L-shaped protruding grip.
- Install new (organic or semi-metallic) pads. They should slide along the rotor, and the spring should not break out of its place.
- Install the bolt, followed by the caliper. To check, you need to press the brake lever several times well. And make sure that the pads have settled correctly and correctly press the rotor.
Disc brake pads should be replaced if:
- decreased braking force;
- a brake “squeal” is heard;
- or an unpleasant grinding noise is heard when the brake lever is pressed.
Riding a bicycle with worn disc brake pads is unsafe. In addition, the rotor (the steel brake disc itself) may fail. And this will already require a serious bike repair.
You will see step-by-step instructions for replacing brake pads on a bicycle with disc brakes in this video review:
How to know when it’s time to change pads?
Don’t wait until it becomes more difficult to stop the bike. It is better to inspect the pads in advance. Outwardly, it will become clear that their service life is over.
Manufacturers deliberately make their surface uneven by providing it with protrusions or spikes.
The more they are erased, the closer the hour when they cease to perform the functions assigned to them.
The process of replacing pads for different types of brake systems is not the same. However, difficulties should not arise even for those who have never changed them on their own before.
How to change the pads on the rim brakes yourself?
If special cables extend from the handlebar brake lever to the wheels, then the bike has a rim brake system. It can be of several types, each of which requires its own approach to work.
- v-brake. To get started, you need to collect all the levers. As a result, a groove is formed, from which it is necessary to pull out the tip of the “shirt”. It is simple to define it: it is from it that the cable comes out. Then remove the old pads by carefully removing the fasteners and put new ones in their place, carefully fixing them.
Sometimes pads of this type are “versatile”, that is, left and right. Manufacturers usually indicate this directly on the details. When installing them, you should be a little more careful.
- Cartridge type. Only the rubber seals are changed here. To do this, remove the cotter pin securing the pads, then perform a simple procedure to remove the worn out gasket and install a new one in the vacant space.
How to change the pads on a bike?
A modern bicycle, as a serious means of transportation, requires constant maintenance. Brake pads especially need attention. Having worn out, they will not allow you to quickly stop the movement. This can lead to very dire consequences.
Although replacing brake pads does not require much skill, even a novice cyclist can do this operation, who has never changed them on his own.
When replacement is required?
You can not miss the moment of changing the brake pads if you keep track of the mileage. As a rule, these parts wear out completely, having served their owner 15 thousand km. Although now there are those that are enough for 30 thousand km. However, these numbers are just a convention. The life of the pads depends on many factors.
Riding style will play a decisive role: the more aggressive it is, the more difficult climbs and dizzying descents the cyclist overcomes, the sooner he will have to think about working with the brakes.
Walking slowly through the park in a relaxed manner will allow the entire braking system to last longer, but only if they are correctly adjusted.
How to change the pads on the disc brakes yourself?
If braking occurs with a special disc, then we are dealing with a disc braking system. Many cyclists consider it to be more advanced. Apparently the manufacturers, too. How else to explain the fact that the bicycles supplied by her are more expensive.
Disc brakes are more convenient not only on the road, but also in maintenance. To change the pads, first remove the caliper. When braking, it clamps a disc that is mounted directly on the wheel and rotates with it. The necessary parts are installed in it.
- To do a good job, the caliper must be removed.
- Carefully deal with all fasteners: wiring, retaining rings and bolts.
- Then remove the old pads and put on the new ones. All that remains is to fix them, put the caliper in place and check if the replacement was made correctly.
To do this, press the brake lever several times, making sure that nothing interferes with the bike’s progress.
There are several rules, observing which, you can afford to carry out the work described above as rarely as possible:
- The brake must be carefully adjusted and it must be ensured that the pad does not permanently clamp the rotor. It is easy to feel this: such a situation will certainly affect the movement of the bicycle, making it difficult;
- You should choose quality parts from trusted manufacturers;
- Avoid situations where emergency braking is required.
Adjusting the V-brake and replacing the pads
We will tell you how to replace the pads and adjust the rim brakes, but if your bike has disc brakes, then this article will help you.
Consider setting up and maintaining a rim brake.
We have already covered the design and variety of rim brakes on our blog. therefore, we will assume that you are already familiar with its construction. In many ways, you can change the force of your brakes by re-adjusting the brake, or by tightening the adjusting bolt on the brake lever. Replacement of pads is performed when their surface is erased to the level of grooves for outflow of dirt (available on all v-brake pads). Those. the working surface becomes completely flat. over, if this happened, only from one edge of the pads, this indicates that they were incorrectly installed. And again they need to be replaced.
Setting up and replacing pads for V-Brake
Replacing the pads:
The tool we need is a 5 Allen key, a 3 Allen key, a Phillips screwdriver, and pliers. Open the brake by bringing the brake levers together with your hand and pulling out the metal arcuate end of the shirt from which the cable comes out of the groove. If you are installing simple new pads, then the main thing is to put on in the required sequence all the gaskets and washers that make up the pads fasteners. And it’s better if you write down or sketch the sequence in which you had them. Sometimes there are left and right pads. This is always indicated on the pads themselves.
The cartridge pads are even easier to change. They have a metal base and only the rubber pad changes. To do this, remove the locking cotter pin, which secures the pad in the shoe, and slide out the rubber pad. Insert new pads and secure with a cotter pin. Do not confuse left and right, otherwise you will not be able to secure them. After the new pads have been installed, they need to be adjusted.
The first thing to do is make sure the wheel is straight. The second thing to do is to tighten the adjusting bolt to the end on the handle itself and release the brake cable on the frame. After that, our frame with pads moves freely and you need to pay attention to the position of the pads, this is perhaps the main process, since it is the pads that contact the rim that make your bike slow down. The pads should be parallel to the rubber and never touch it. Please make sure that the pads on your bike are installed correctly according to the pictures below.
After the pads have been exposed, and the cable is fixed in the frame back. there should be a small gap of a couple of millimeters between the pads and the rim itself, and the wheel itself should move freely, the pads should not rub against the rim. Thus, we adjust the desired brake lever travel, it can be changed by releasing or, on the contrary, by pulling the cable relative to the brake lever. Then we look at the position of the levers and pressing the pads when the brake lever is pressed, note that the pads must move synchronously with each other, if this does not happen and one side is pressed and the other is not, then the adjusting bolts on the springs that are located at hinges securing the levers (legs). Adjustment takes place by releasing one side and proportionally twisting the other. After the frame is exposed and everything works in sync, the rim brake setting can be completed.
How to adjust everything yourself
It may be necessary to adjust the hydraulic brakes if you notice extraneous sounds while driving. creaking or rustling. A simple test will help to make sure that the adjustment is necessary: lift the wheel of the bicycle and spin it. If the pads touch the brake disc, the wheel will quickly stop spinning.
The relative position of the pads and the rotor must be very accurate, because this affects the performance of the brake. To check the position of the disc in the typewriter and the position of the pads, place a white sheet under them and, if necessary, direct a bright light on it. against such a background it is easier to notice deviations.
Adjust the hydraulic brake as follows: 1. Loosen the caliper mounting bolts as much as possible so that it can move freely to the sides.
Squeeze the brake lever so that the pads are fully pressed against the rotor.
Check the position of the pad valves. they should be symmetrical, at the same distance from the rotor. Move the caliper slightly to the left or right if necessary.
Without releasing the brake lever, tighten the caliper mounting bolts.
Release the handle and check the brakes. Ideally, the pads should be at a minimum distance from the brake disc, but not touching it.
If you notice that one pad is located closer to the disc than the other, but the rotor itself is perfectly centered in the machine, do the following (preferably two people): press the disc against the more protruding pad and apply a little brake. Due to the fact that one valve works more than the other, they will align, and the problem will be eliminated.
The final touch is to set the position of the brake lever relative to the steering wheel. Sitting in the saddle, check if you feel comfortable using the brake lever and if you can quickly press it in an emergency. If the knob is too far for you, tighten the adjusting hex a little more. this will bring the knob closer, but at the same time the pads will move closer to the rotor. The main thing here is not to overdo it and not to make the stroke of the pads too small.
Adjusting the bike’s hydraulic brakes and replacing the pads
The principle of operation of hydraulic brakes on a bicycle is to transfer pressure through the hydraulic line from the brake master cylinder to the brake cylinder in the caliper, which in turn moves the pads. The brake fluid is not compressed, therefore such a system is more reliable and efficient than a mechanical one.
On the other hand, hydraulic lines and the entire braking system require careful attention and constant maintenance, and therefore repairing and adjusting hydraulic brakes often seems to be a difficult task.
Replacing the brake pads
Poor operation of hydraulic disc brakes may be due to the following reasons:
- damage or contamination of the hydraulic line or ingress of air into it;
- complete abrasion of the brake pads;
- dirty pads or disc.
In the first case, replacement of the hydraulic line or bleeding of the hydraulic brake is required, with the second and third cases it is easier to deal with.
First, take a close look at the brake pads. All manufacturers prescribe their minimum thickness, at which the braking performance does not decrease. By the way, the uneven wear of the left and right pads indicates that the rotor is not centered relative to the caliper.
As the pads wear out, the valves move closer to the rotor, so before installing new pads, you should slightly move them apart and re-adjust their position. The entire replacement procedure consists of the following sequence of steps: 1. Place the bike on a repair stand and remove the wheel.
Remove the retaining ring and unscrew the fixing bolt.
Pull out the old pads away from the wheel hub axle. Remember the location of the return spring between the pads. it releases them after the end of braking.
Thoroughly clean the surface of the valves and the inside of the caliper. Use a lint-free technical cloth and a mild cleaner such as isopropyl alcohol.
Using a plastic lever, such as a tube changer, press both valves into the caliper. To install the valve correctly, you need to press on its center, not on the edge.
Install a return spring between the new pads and insert them into the machine.
Tighten the fixing bolt and install the retaining ring.
Clean the brake disc and replace the wheel. Check the correct position of the rotor, pads and the functionality of the entire system.
New pads may require a period of “adaptation”, so at first, the updated brakes should be used carefully.
it should be said that all work should be done with clean hands. Also, to keep the brakes less dirty, you should close them when lubricating the chain. With a comprehensive bike service, the brake system is repaired last.