Bicycle rear brake
Brakes for a bicycle, like for any other vehicle, are an indispensable element necessary for handling a bicycle and ensuring safety. The following types are distinguished:
- Drum brakes.
- Rim brakes.
- Disc brakes.
Which type of brakes should you choose? To answer this question, it is worth understanding the features of each type of brakes.
The drum brake (otherwise called “foot brake”) is located in the rear hub of the bicycle and has brake pads inside. The braking process is initiated when the carriage rotates against the movement.
As a result, the brake pads are pulled apart and pressed against the drum. Friction occurs between the pads and the drum, due to which braking occurs. Drum brakes are commonly found on children’s bicycles (e.g. Forward Meteor 12, Forward Timba girl) and inexpensive city bikes for adults.
- Durability. thanks to the closed mechanism, dirt, dust and moisture hardly get into it.
- Drum brake does not cause wheel rim wear.
- Easy maintenance. no need for regular inspection and adjustment.
- Efficient. works even when the wheel rim is bent.
- Are heavy.
- force is required to brake than other types of brakes.
- Cannot be used on multi-speed bikes.
- The presence of a “dead zone”. when it is impossible to brake with the vertical position of the connecting rods.
- There is a risk. if the chain falls off the sprocket and the front brake is not installed on the bike, the bike cannot be stopped.
- It takes time for the transition from moving forward to the beginning of braking, which in some cases can be critical.
This is the most popular brake type today. The principle of their operation is as follows: when a force is applied, which is transmitted through a cable to the brake levers, the brake pads on the brake levers fit tightly to the wheel rim, which ensures braking. Rim brakes are cantilever, caliper and V-brake.
Their mechanism consists of two levers with brake pads attached to the pivots on the fork. With the help of a pair of rods, the cable moves the levers, after which braking occurs. This mechanism is simple and reliable, but it is encountered less and less. It is superseded by other other types of brakes with more effective stopping power.
Most often used on road bikes, but there they are gradually being replaced by other types of brakes. The name of the brakes speaks volumes about its design: the brake pads are pressed against the rim by curved levers that look like pliers.
V-brakes are applied in the same way as cantilever brakes. The brake cable is routed from the side to the top of the brake arm. The brake lever compresses both parts of the brake with cartridge brake pads. This system of parallel padding allows for efficient braking.
In addition, cartridge brake pads can be easily changed using a conventional hexagon. At the moment, this type of brake is the most common. Since V-brakes are the most common type of rim brakes, it is worth considering their advantages and disadvantages separately.
- Simple and efficient design with good braking power.
- Lightweight compared to disc or drum brakes.
- Low price.
- Reduced braking performance if moisture or dirt gets on the rims and brake pads.
- Acceleration of the wear of the rim and brake pads due to increased friction when dirt, sand gets in.
- Wide tires cannot be used with V-brakes.
By the way, we recommend:
Disc brakes with minor changes, modifications and adaptations came to the cycling world from the world of motorcycles and cars.
Depending on the type of drive, disc brakes are divided into mechanical and hydraulic. In a mechanical disc brake, the force from the brake lever to the brake pads is transmitted by a cable, and in a hydraulic disc brake through a hydraulic system filled with brake fluid.
When you press the brake lever at the mechanical brake, a cable is pulled, this force is transmitted to the brake pads, which, pressing against the brake disc, lead to braking. In the case of a hydraulic brake, the required force is transmitted through the hydraulic line from the brake lever directly to the pads.
Bicycle disc brakes: device
A disc brake consists of a brake disc (rotor) attached to the wheel hub, and a brake machine (caliper), inside which the brake pads are located. Disc rotors come in several sizes: 140, 160, 180, 185, 203 and 220 mm. The larger the rotor diameter, the more efficiently the brake works, as the arm of the brake force lever increases.
The caliper (brake machine) is mounted on a fork or frame. Inside the caliper there are two brake pads that are pressed against the rotor by one or more pistons.
Brake pads can be filled with metal filings or organic material. Metal-filled pads last longer and are more resistant to wear and tear. Organic pads are softer, wear in quickly and provide smoother braking.
Disc mechanical brakes
Mechanical disc brakes are usually installed on mountain bikes (Forward Next 2.0 disc, Forward Agris Lady 27.5 2.0 disc, etc.) and touring bikes (Forward Yukon 2.0 disc), less often on city bikes ( For example, Forward Tracer 2.0 disc).
- Difficult to repair in the field without special tools.
- Unlike V-brakes, the various models and modifications of disc brakes make it very difficult to find spare parts for them.
- Danger of twisting the rotor on the removed wheel when transporting the bike.
- Potential difficulty attaching a standard bike rack.
- Heavy weight relative to rim brakes.
- High price relative to rim brakes.
- It is necessary to keep the shirts and cables clean and lubricate them regularly, while the grease should have an optimal density, should not leak from the shirts.
Now that you know the features of different types of brakes, their pros and cons, it will be easier for you to choose a bike with the most suitable brakes and how to maintain them further, for example, adjusting the brakes.
Brakes, especially disc brakes, need to be adjusted very rarely. For rim types, this is once a season, for other options up to once every few years. Nevertheless, after a long downtime or repair, as well as when symptoms of incorrect operation of the brake system appear, adjustment is simply necessary.
Bicycle brake problem symptoms
How do you know if your bike needs brake adjustment? There are several signs:
- You bought a bike. new mechanisms require running-in and constant, in several approaches after a short run, adjustment.
- You have not used your bike for more than a month. especially if it was cold storage, the maintenance of the pads and the brake mechanism is imperative.
- “New” sounds are heard from the mechanism: buzzing at speed, periodic knocking, whistling, squeaks. problems with mechanical parts or block.
- The brakes began to react poorly to effort, that is, they only work after a certain stroke, do not immediately “release”, etc. a clear sign of cable or hydraulics problems.
- Visual damage to the cables or elements of the brake mechanism. they can continue to work, but it is simply necessary to adjust after, for example, an impact.
Adjusting rim brakes
Adjustment of rim brakes (almost all modern ones are of the V-Brake type) is very simple and does not require any special conditions. over, due to the “openness” of the mechanism, maintenance usually consists not in working with the structure, but in replacing the pads.
Before adjusting, the first thing to do is to make sure that the rim brakes are indeed V-brakes. Actually, there are three types of rim mounts:
- V-Brake. separate V-shaped levers, connected by a cable that is held by a leash (jacket);
- cantilever. with an additional central attachment, from which the cable goes separately to each side. In fact, these are the predecessors of the V-Brake, characterized by a more complex mechanism, but a large clearance, which is beneficial for “dirty” riding;
- caliper brakes. U-shaped mount, in which two levers are connected and “bite” the rim. These models are the hardest to weaken.
For smooth operation of the rim brakes, you need to monitor the integrity of the cable and the absence of “eights” on the wheel. If at least one fiber is broken on the cable, it must be replaced. The cable should run freely in the shirt, and if it gets stuck it is necessary to change either the cable or the shirt. The main thing in the high-quality operation of rim brakes is the high-quality pressing of the pads to the rim. This can be adjusted by fastening the pads. The fastener consists of a set of washers, gaskets and a nut, it allows you to fix the shoe at the desired angle.
To adjust, loosen the nut on each shoe slightly so that the shoe can be moved with your fingers, but it will not move. Place the block parallel to the wheel rim, pay attention that it must not touch the tire (the distance between the block and the tire must be at least 1 mm.).
If you have soft rubber brake pads, they will deform when you brake. Therefore, they must be installed so that the leading edge of these pads is 1 mm. closer to the rim than the rear. To do this, place a 1-1 thick gasket under the rear parts of the pads before adjusting. 5 mm. For example, a piece of rubber cut from a worn bicycle tube.
If you have brake pads with a rigid base that do not deform when braking, you must install strictly parallel to the rim.
Then firmly press the brake lever and tighten the nuts on the pads, carefully watch so that they do not change their position. Then look at the brake levers. Squeeze and release the brake levers several times, the levers should converge and diverge equally. This can be adjusted with the spring tension screws located at the base of the lever. We turn the adjusting screw on the lever that deflects too little, and unscrew it if the lever deflects too much. In order to remove the wheel, you do not need to unscrew the brake cable, you just need to release it from the clamp. To do this, squeeze the brake levers with your hands and remove the rigid part of the cable jacket from the slot.
Whatever your choice, do not forget about the importance of braking elements as an integral part of the bike. Your safety depends on them, so you need to take them seriously and responsibly. The brakes on the bike play a major role in the ride. It is easy to see this on slopes and other irregularities. That is why it is so important to pay special attention to them. This applies to both the front brake and the rear.
The text was prepared by Roman Borisov. Published: May 5, 2020. Sources: forwardvelo.ru, velosreda.ru, velofans.ru. Categories: Choice.
How to adjust the rear brakes on a bike. Self-adjusting the brakes on the bike
Cycling is an incomparable pleasure. A constant wind in your hair, a feeling of complete freedom and independence, besides, cycling can replace constant trips to the gym, it’s no secret that riding a “two-wheeled” affects absolutely all muscle groups. First of all, legs, back, arms, abs. all this is maintained in an active tone thanks to cycling. The benefits of a bicycle cannot be understated. But in order to enjoy walks day after day, you need to take care of your “horse”. Preventive maintenance includes brake adjustment.
Safety comes first! Yes, this rule is worth remembering every time you want to ride a bike. After all, many “ordinary” walks end with injuries.
Bad brakes are every cyclist’s problem. I don’t really want to carry out checks before each trip. It is tedious and time consuming. But here’s the problem. it’s necessary. A routine brake check can save lives and health. Adjusting the brakes on a bicycle is a painstaking task. Therefore, it is so important to be able to do it right.
Varieties and models of bicycle brakes
Brake adjustments on a bicycle can vary. In each situation, it is worth looking at the type of braking system. Most often, cheap bicycles are equipped with mechanical rim brakes, or, as they are also called, V-brakes.
Disc mechanical brakes
Everything is on the rise. And as you might guess, disc brakes are second in the list of systems of this type. What kind of changes can you see here? All the same levers, the same metal cables. Only the brake itself has been changed. The disc is now bolted to the bicycle wheel. Nearby are two clamps with pads. Yes, the disc wheel is in direct contact with the clamps.
This innovation increases grip. Now, if you hold down the lever, the wheel will not spin. This is why disc brakes are used on sport bikes. With it, the braking distance is halved. And this is what needs to be achieved. Adjusting disc brakes on a bicycle is different from the technique of adjusting rim brakes. So it can be tricky to ride V-breaks all your life and then switch to disc brakes. After all, you will have to learn to configure this system again.
Disc hydraulic brake
So, the winner of the rating. It is hydraulics that rules the world of brakes. How does this system work? There are handles, there is a disc and there are braking elements. They are connected together by rubber tubes, inside of which there is oil, or, as it should be correctly said, brake fluid. What are its pros and cons? The hydraulics are responsive to every pressure. It can be said to instantly transmit pressure. That is why many athletes and extreme sportsmen use hydraulic disc brakes on their bikes. After all, the accurate transmission of sensations helps to win important seconds. The hydraulic brake firmly compresses the metal disc so that, when pressed hard, the rider can literally fly out of the saddle. But, like everyone else, hydraulics have their negative sides.
First, the high cost. This, of course, is a dubious minus, because this system is bought not by ordinary amateurs, but by professionals. Second, the fix issue. Yes, the hydraulics simply cannot be fixed by yourself. The slightest upset. and a trip to the workshop is guaranteed. And again, repairs will cost a pretty penny. Parts of the system, such as tubes, are not very reliable. If this part bursts, brake fluid will escape. Therefore, you can only brake with your feet. Adjusting hydraulic brakes on a bicycle is tricky. This, if possible, it is better to entrust the master.
First steps in repair and adjustment business
As always, start simple first. In this case, from the repair of the simplest brake system. rim. V-breaks are not famous for their ingenuity. A simple device as two and two. What does this mechanical brake system consist of? There are levers that are mounted on the steering wheel. There are tubes (it is correct to call them “shirts”), inside of which an iron cable fidgets. Two clips and pads. Everything is nothing more. That is why there are only three positions on which to regulate the V-break.
Adjusting the rear brakes on a bicycle
In theoretical terms, everything is clear. Three parameters, three actions, and only one result. well-tuned brakes. Once again. this is in theory. In fact, it is difficult for beginners to do everything perfectly. Adjusting the rim brakes on a bicycle is a delicate thing. So you have to be patient first.
So the first step is to adjust the pads. They should be parallel to the rim on both the rear wheel and the front.
Especially do not tolerate the striking of this element on the tire. A couple of kilometers. and the rubber will be frayed to holes. It is undesirable for the block to also go beyond the boundaries of the wheel. From this, it is quickly erased, but the desired effect (good inhibition) is not. Therefore, it is so important to correctly adjust the position of the brake pads. Adjusting a mechanical brake on a bicycle begins with the selection of tools. You will need: a hexagon, a screwdriver and a 12 key. For rubber clamps, you should take only a hexagon. It is worth starting by holding the brake lever. This will push the pads against the rim. Having examined the situation, you can immediately see where something is wrong. Use this tool to loosen the washer. Then, while still holding the brake lever, align the rubber clamp in the desired direction. The same is worth repeating on the other side. This is just the first step towards a perfectly tuned brake.
Adjusting the front brake on a bicycle
The hardest part lies ahead. Do not be afraid, you just need to concentrate. So, you need to adjust the distance between the pads and the wheel. It is important. Again, action monitoring is similar for the front and rear brakes. It is worth remembering that if the distance is too large, the clamps will not fit well. Therefore, there will be no inhibitory effect. If, on the contrary, you leave little room for the brakes, they will strike the rim. This will quickly wear off the pads, and the wheel will constantly brake. In general, you can adjust the distance between the pads and the rim using one nut, which is located on the levers, on top, where the metal cable is attached.
It should be unscrewed, thereby loosening the grip. From this action, the levers will part, do not be afraid. With the force of your hand, you need to lean against the rim. Then squeeze the brake lever so that it does not reach the steering wheel for a couple of centimeters. Keeping the levers in the same position, screw the nut back. Adjusting the brakes on a bike doesn’t stop there.
The springs that are part of the mechanical rim brake system are also responsible for the distance between the wheel and the block. But, unlike a nut with a cable, they allow you to adjust the distance down to a millimeter. That is, more precisely. The spring tension can be changed with a single bolt that is screwed on and off every now and then. This bolt is located on both sides of the brake. Therefore, when a situation arises that one side touches the rim, and the other is separated, you just have to tuck the bolt. and everything will fall into place. When this element is twisted, the spring becomes “harder”. Consequently, the distance will increase. If you unscrew the bolt, the spring will weaken. From this the distance will decrease. So, by adjusting each element, you can achieve perfect accuracy.
Bicycle disc brakes can be adjusted with just two screws. The first is responsible for the distance between the disc and the pad. The second is responsible for its location in the vertical plane. Therefore, if the rubber clamps are constantly touching the brake or, on the contrary, the disc has left the “contact zone” of the pads, you just have to work hard with a screwdriver. Through trial and error, you can understand what is responsible for what, and then it’s a matter of technology. By tightening the screw, you can immediately adjust the position.
Hydraulic disc brake
Adjusting the brakes on a hydraulically equipped bicycle is difficult. To do this, you need to have special tools and special skills. But you can do everything to prevent breakdowns. Prevention will help the hydraulics not break down and serve the owner for a long time.
Adjusting the brakes on a bicycle
Adjusting the brakes on a bicycle should be carried out regularly. such maintenance will guarantee the safe operation of the vehicle. There are two main types of brakes on modern bicycles. rim and disc brakes, but disc brakes can be mechanical or hydraulic. The type of brake system installed on a particular bike will determine the process of their maintenance.
How to check and adjust the brakes
There are clear instructions for checking and adjusting the brake system of a bicycle. If you adhere to it, then the whole process will take little time and will be effective.
Procedure for checking and adjusting the brake system of a bicycle:
- Dry brake test. It is necessary to raise the front wheel and, having unwound it, press the left brake lever. If the wheel comes to a sudden stop during this test, the braking system is in order and no maintenance is required. It is worth considering one nuance. if the brake lever touches the steering wheel, then you just need to pull the cable. The operation of the rear wheel brake system is checked in the same manner. To tension the cable, you need to use curly bolts. just tighten them a little and, if only minor adjustments are required, this will correct the situation. It often happens that such a minimum adjustment does not work. in this case, we look where the end of the cable is on the bike (it is always longer than necessary in advance), unscrew the bolt that holds it. It remains only to tighten part of the cable with pliers and tighten the bolt, applying the possible force.
- Checking the brake pads. After the brake levers have been tested, the condition of the brake pads should be carefully examined. However, the order of action can be changed. first work with the pads, and then with the handles.
The brake system setting is different for rim and disc types, since different rotating mechanisms and pads are used.
Adjusting the rim brakes
Mountain bikes use a v-brake braking system. using this as an example, we will consider the principles of tuning, since it is also available on other bicycles with rim brakes. The difference can only consist in a different arrangement of bolts and screws that will need to be tightened / tightened.
Note: it is important to observe three main rules:
- the pads should be parallel to the rim;
- the gap between the rim and the block should not be more or less than 1 mm;
- the pads should be symmetrical in relation to each other.
How to achieve these guidelines when adjusting rim brakes on a bicycle:
- You need to find a hex nut. it fixes the pads. To loosen it and set the brake pads in the desired position, you will need to press the brake lever and watch how the shoe touches the rim. By releasing the brake lever, the shoe can be set to the desired position. it moves up, down and at an angle.
- The distance between the shoe and the rim of the wheel should not be more than 1 mm, although in some models of bicycles there are also 2-3 mm. exact information about a specific vehicle can be obtained either from the instructions for it or on the Internet for technical characteristics. It should be noted that braking of the wheel should occur even with the minimum pressing of the brake lever. That is, if the wheel stops only when the brake lever is fully pressed “all the way”, then this is incorrect.
After carrying out all the specified work, it is imperative to check the operation of the brake system. First, this is done at idle speed. lift the front wheel up, spin it up and press the handle sharply, then do the same with the rear wheel. The next step is to check the operation of the brake system “in action”. get on the bike and ride 3-5 meters, braking sharply. If the bike has stopped even with a minimal pressure on the brake lever, then the system has been serviced correctly.
Setting up disc brakes
As a rule, adjustment of disc brakes consists in periodically tightening the cable. But often you have to replace the pads, however, on disc brakes they wear out longer than on rim brakes. First you need to find out which specific disc brakes are installed on the bike. brake pad adjustments for hydraulic and mechanical systems will differ.
Experts recommend taking note of the following points:
- If there are hydraulic disc brakes on the bike, then replacing the pads may not be necessary. they are able to do it on their own. But one caveat should be taken into account. if the hydraulic system is closed, then you will have to adjust the pads in manual mode. for this, special valves are provided.
- If you have to adjust disc mechanical brakes, then you will need to pull the cable according to the above instructions and check the location of the pads. the distance between them and the disc should be within 0.2-0.4 mm.
- In order to adjust the pads with disc mechanical brakes, you need to use special bolts. by tightening them, you can see how the pad moves. You need to be especially careful when setting the distance between the pad and the disc. 0.3 mm is too small, it’s easy to make a mistake.
Be sure to check the operation of the brake system in action after the work is done. ride your bike for a few meters and try to brake. If the cable is too tight, or the pads are too close to the disc, then too sharp braking will occur. this is a “surprise” in which the cyclist begins to move forward, but without his vehicle. Therefore, when driving for a test, you need to be extremely careful and careful, if necessary, the disc brake system is adjusted again taking into account previous errors.
How to set up rim brakes on a bicycle
8 minutes Author: Mikhail Skvortsov 312
The braking system is one of the most important technical components of a bicycle. The safety of both the cyclist and other road users directly depends on its condition. Good brakes are essential in any situation, from riding in parks to strong cycling.
In the modern classical sense, a bicycle brake is a pressure mechanism that acts on the wheel rim. There are actually several types of brakes, however v-brake (rim) is the most common option on bicycles of various classes.
Braking system characteristics
The following terms are used to qualitatively describe the operation of rim brakes:
- impact force;
- wear resistance;
- service requirements;
- comparative features.
Force of impact, or braking, is a parameter that shows how much the brake can clamp the rim so that the bike cannot be moved. Maximum effort is required only to stop completely and lock in place. On the road, the effort is not fully used to adjust the speed. The range of action on the wheel rim by pressing the handle is called modulation, or accuracy, of the brakes.
An active cyclist uses his transport not only in dry and cloudless weather. Rain, mud, sand. everyone who rolls out their bike on long trips will have to face this. The effectiveness of brakes allows you to describe their behavior in a wide variety of conditions.
Durability is a measure of durability, taking into account the prescriptions for using the bicycle as a whole. Timely maintenance can increase the service life of the braking system. Service Requirements describe how to properly install and adjust the mechanism, how often to do this, and guidance on how to replace parts.
Varieties of rim brakes
Rim brakes are divided into several types:
- V-brake (vector mechanical);
- hydraulically driven.
Caliper brakes. previously popular modifications, are now rare on the market. They are a classic model of rim brakes that are attached to the fork or stays of the bicycle frame. Design features and operating principle:
- Consist of a handle, a drive cable, two movable bows and brake pads.
- The handle is attached to the handlebars of the bicycle, a cable is pulled from it and fixed on the clamping side of the arches. The body itself is attached strictly above the wheel, pads are screwed to the lower arches.
- Through the cable, the force is directly transmitted to the clamping part of the arcs, due to which they are compressed, and the pads are in contact with the rim.
- Responsible for the release is an elastic metal insert or spring built between the levers.
The levers have a single axis of rotation and move towards each other like pliers pincers. Hence the name. tick-borne. Advantages. ease of installation, simple setup. Cons. weak braking force, low modulation, high abrasion of the pads, require frequent debugging. Fits on road racing bikes and optionally as a front rim brake on road models.
Cantilevers belong to the second type of disappearing brakes. The principle of their operation is to extend the levers under the action of a stretched leash. Cantilever brake working principle:
- Through the main cable, the force is transmitted to the jumper.
- The cable pulls the jumper up, the leash attached to it is pulled.
- The leash connects both levers, which are rigidly attached to the frame.
- Due to the convergence of the levers, the pads approach the rim.
The cantilevers are dirt resistant, will not bump the tire and are easy to install. Significant disadvantages include:
- decrease in braking force as the leash is pulled;
- you need to create a high effort to stop the bike completely;
- difficulty of adjustment.
To justify the latter, it is worth noting that the position of the pads can be adjusted within wide limits.
V-brake is a common type of rim brake on high-speed bicycles. Compared to cantilevers, it has a higher precision and longer shoe longevity. They are also easy to remove and repair yourself.
The vectors are partially similar in design to cantilevers: the front brake levers are bolted to the fork, the rear brake levers are attached to the upper stays. The legs are tied together with a pulling cable. The drive cable is brought to one side, but due to the straight form of the “tie” forces are equally transmitted to both levers.
Hydraulic bicycle rim brakes are a more advanced mechanical model. The drive system consists of a control cylinder, a hydraulic line and power cylinders. The forces from the handle are transmitted to the master cylinder, which, through the oil, acts on the power cylinders. Those, in turn, shift the pads towards each other.
Advantages. high compression force and efficiency, excellent modulation. Disadvantages. deterioration of performance when the hydraulic line is clogged, difficult repairs. Used a similar type of brakes for freeride and trial.
Rim-type brakes have low brake pad travel, which means they wear less during operation. A significant disadvantage of this approach is the inability to be used on wheels even with minor rim curvatures. Sensitive brakes will rub against the wheel on the fly, causing reduced speed and increased pad wear.
How to install and configure V-brake yourself
Installing the brake from scratch:
- Attach the levers to the bike frame.
- Insert the drive cable into the brake lever.
- Install the handle on the steering wheel, insert the cable into the grooves on the frame (if any).
- Connect the cable to the levers and put the spring.
After installation, you will definitely need to adjust the brakes.
The accuracy of the mechanism largely depends on its settings. So, even an expensive system will not work well without proper adjustment, and conversely, a mid-range V-brake can outperform a disc brake in efficiency. What needs to be done to adjust the brakes?
Adjust the cable tension. After adjusting, the brake should instantly respond to squeezing the handle and rebound when it is released. If the pads do not move away from the rims, this indicates insufficient tension. On a tight cable, the handle will be hard to press, and the sheath may burst.
The tension is adjusted with a bolt on the side of the levers. The setup looks like this:
- Reset Springs.
- Loosen the cable fixing bolt.
- Adjust the tension so that in the fully clamped position the distance from the handle to the handlebars corresponds to the thickness of the finger.
If damage was noticed on the cable sheath, it is recommended to immediately install a new set.
Clearance adjustment. The optimal distance is 2. 3 mm from the edge of the pad to the rim. Determination of brake pad wear: cannot be used when the diverter grooves are completely erased (the whole surface is flat).
How do I fit new pads? The location relative to the rim affects the size of the contact area of the pads with it, the braking force and the life of the material. For brake pads with soft rubber surfaces, install them with the leading edge closer to the rim. Brake pads made of hard material are placed strictly parallel to the wheel rotation surface.
If your bike has cartridge pads, you only need to change the pads. Their position is set with a cotter pin; before removing the old surface, it is removed from the body. Similarly, in the reverse order, insert a new pad and fix it with a cotter pin.
Adjustment of the position and displacement of the shoe housings are carried out by means of a bolt and washers. For accurate fixation, you need to squeeze the brake and set the position of the pads strictly on the surface of the rim.
The last step will be to test the operation of the system in practice, that is, in real driving conditions. As a rule, the V-brake setting is obtained immediately. However, if braking is delayed or the handle does not fully return to its original position, the brakes must be readjusted.
Adjusting the brakes (V-Brake)
Braking tuning requires attention to every detail, from the brake levers to the brake pads.
First step. Adjusting the brake levers
Brake levers should be located so that they can be reached quickly and comfortably. In order to adjust the position of the brake lever, loosen the fastening screw, place the handle as it is convenient for you and fix it. Usually there is a screw on the brake lever, with which you can adjust the distance of the brake lever to the grip. adjust the position of the lever with it.
Step two. Position of the brake pads
It is easier to adjust the position of the brake pads as follows: press one of the pads with your hands close to the rim, adjust its position. Make sure that the block is not too low (the edge of the block is below the rim), but not too high. the block touches the tire.
I would like to draw special attention to the next moment, since there is little clear written about it. Until the nut of which the shoe is fixed is not tightened, the shoe has three degrees of freedom: the washers form something like a ball joint. (Pay attention to how many washers are there? That’s what they are for!). It is believed that the leading edge of the pads should touch the rim slightly earlier than the rear. Therefore, we do this: we put a small gasket under the rear end (see fig.).
This number of washers is needed to get something like a ball joint
Now you can tighten the nut that fixes the shoe.
Step three. Centering the positions of the levers
At this step, you need to fix the brake cable: so that the brake pads touch the rims at least a little if you press the brake lever. At the bottom of the levers there are special bolts that adjust the tension of the springs that press the pads against the rim.
We set it up as follows: press the brake and see which of the pads touches earlier. For the one that touched earlier, we increase the spring tension (or vice versa, weaken it on the other side). It is necessary to ensure that the pads touch the rim at the same time.
Fourth step. Adjusting the distance from the pads to the rim
I believe that this distance should be as small as possible. (1-2 mm. If the rim is even). But then the brakes will work very sharply. the slightest pressure leads to sharp braking. Therefore, the distance can be made a little more.
The distance is adjusted in two steps: first, due to the screw with which the cable is attached to the brakes. Then fine tuning on the brake lever.
The large washer acts as a lock: when it is tightened, the cable tension adjustment screw cannot be turned.
Brake adjustment (V-Brake): 7 comments
Sheer nonsense is written: “At the bottom of the levers there are special bolts that adjust the tension of the springs that press the pads to the rim.”. With what fright does the springs press the pads to the rim, if their task is to remove the pads from the rim? When we tighten the adjusting bolt on the handle, the pads are not closer, but farther, and, accordingly, vice versa, when Unscrewing the pads CLOSER.
Correct and do not disgrace, but rather do not get into questions that you absolutely do not understand.
There is one cable and two pads. The springs press the shoe against the rim, one stronger, the other weaker. This allows the pads to be equally spaced from the rim.
Wash an excellent article. I began to understand what was happening and set up the rear brake. Smit. thanks for the amendment about the spring adjusters, this clears all other questions. Thanks to the author for the intelligible presentation and images of adequate size and quality. PS: I’m not that stupid, but when adjusting the handles I confused the front with the rear and after 5 minutes of adjustment I accidentally adjusted the front brakes)))
Thank you very much only I knew it
Thanks! Clear and well stated.
And after all, not a single surveyor can really explain how the adjusting screw works, which is responsible for the tension of the cable on the steering wheel. Why, when REMOVING, its cable is pulled and vice versa ?
The cable length does not change. When unscrewing, the tube is lengthened by the length of the unscrewed thread, the cable has nowhere to go and it pulls the pads. It’s like with sleeves on a shirt, the longer the sleeves, the less the arms are visible.
Adjusting bicycle brakes of various designs
Depending on the class of cycling equipment, three types of devices are installed on it to ensure a stop: drum, rim, disc. Each of the designs has its own advantages and disadvantages, it is operated in different ways and has specific brake adjustments on a bicycle, which we will dwell on in more detail.
The most common type of device for controlling speed, stopping bicycles designed for city trips, including children’s models. It also has a second name. foot. The assembly is located in the rear wheel hub, and the process is initiated by reverse pedaling. The pads inside the drum are pressed against the walls of the drum, as a result of which friction slows down the movement of the rear wheel.
Due to the simplicity of the design, adjusting the drum brakes on a bicycle is not necessary. The block is durable, isolated from dust and moisture, and is effective even when the wheel is deformed. However, there are a number of disadvantages of the drum design. It:
- the need to apply great efforts to trigger;
- the inability to use it when the chain has flown off on the move;
- the presence of a “dead zone” and a transition period from decision-making to the beginning of the physical process.
Types of shoe or rim structures
It is by far the most common and popular design found on most bicycles. There are three types of shoe blocks:
They have several differences, but their principle of operation is the same: a force is applied to the levers, which, through the cables, presses the pads against the rim of the wheels, slowing down their rotation. They are balanced by shifting the pads. To do this, the fastening nuts are loosened, and each of the pads is positioned relative to the rim. In this case, it is necessary to maintain a distance of at least a millimeter between the tire and the block. The cable tension is set with a hollow nut on the brake handle. The features and procedure for adjusting the V-brake rim blocks are described in detail in the video review https://youtu.be/fAu7p5nZ1Ok.
For cantilever systems, reach adjustment is applied using a screw located in the handle, which changes the tension of the cable that transfers the forces to the pads.
For tick-borne types, the bicycle handbrake settings are performed using the pad adjusters and the cable eccentric.
Speaking about adjustments of rim systems, it should be noted that for all types they are reduced to adjusting the position of the shoes and the tension of the cable. Block blocks due to their design are highly efficient, lightweight and inexpensive. At the same time, the ingress of water or dirt on them increases the distance to a complete stop, accelerates the wear of the wheel rim. And one more nuance: V-brake cannot be used on bicycles with wide tires.
So, if you do not know how to set up rim brakes on a bicycle, then you should turn to more experienced members of the cycling community or a professional mechanic. But, nevertheless, it is easier and more convenient to master this simple process on your own, using the numerous video reviews and descriptions contained in the accompanying documents for your bicycle, especially since all the necessary tools are included in the package.
How to set up disc brakes on a bicycle
Disc brakes are of two types:
- mechanical. the pads are driven by a handle and cables;
- hydraulic. in such systems, pressure on the pads is carried out using a process fluid under pressure.
Mechanics are easier to repair, but hydraulics are by far the most powerful braking device installed on bicycles. Before adjusting the brakes on a bicycle, make sure that its parts are free from critical wear and mechanical damage. If the disc has a curvature, it must be corrected with a rotary or adjustable wrench.
When adjusting disc brakes on a bicycle, it is very important to correctly position the pads relative to the disc. This is a basic adjustment made with two Allen screws. Follow the link https://youtu.be/-wzOEfLWTpU you can get a visual understanding of the process by watching the video on how to set up disc brakes on a bicycle.
And remember that the front brake of the bicycle must be adjusted in such a way that even when the handle is pressed sharply, braking occurs smoothly, otherwise you cannot avoid the sharp blocking of the front wheel, which is fraught with overturning of the bike. In case of emergency you will be backed up by the bike’s rear brake settings, quickly and clearly provide a stop.
Rear wheel brake adjustment.
Install the rear wheel brake lever 3 (Fig. 9) with a hook so that in the extreme upper position it rests on the roller 4 of the driver’s footrests, and with the adjusting screw (Fig. 27) located in the sprocket casing, ensure free play of the brake lever pedal down by 5. 15 mm.
Figure: 27. Rear wheel brake adjustment
Adjustment of the double-cam drum brake.
Make adjustments in the following order:
unpin and remove the pin from the connection of the rod with the left short lever. Using the adjusting screw 5 (Fig. 23), when unscrewing the gap between the shoes and the brake drum, adjust the tension of the brake cable so that when the wheel rotates, the lower shoe touches the brake drum, then tighten the adjusting screw 1/2 turn;
by turning the left lever clockwise, bring the upper block until it touches the brake drum of the wheel and adjust the thrust 2 so that the gap between the shoe and the brake drum is the smallest and ensures wheel rotation without touching the block. If the holes do not match, adjust the rod length by loosening the lock nut. Insert the pin into the hole of the left arm and tie rod and cotter;
set a free travel of 10.20 mm at the end of the front wheel brake lever. It is not allowed to touch the brake shoes on the drum. The degree of wear of the brake pads is determined by the position of the flag 4 (Fig. 23). The maximum permissible wear corresponds to the coincidence of the flag with the mark “1” on the brake drum cover when the hand brake lever is depressed. When assembling, set the flag to the “0” mark (the brake lever is not connected to the cable). After adjusting the brake, the flag will take a position between the marks “0” and “1”.
To improve the operation of the front wheel brake drive in the spring-autumn period, we recommend lubricating the front brake cable rope with motor oil or brake fluid, and position the adjusting screws with the groove down. Lubrication is performed by dipping the rope into a container with oil and subsequent movements of the shell (5-10 times) along the rope.
Rear wheel drive chain
Figure: 28. Installing the chain lock latch, chain tension control
To apply lubricant to the chain, disengage the lock, remove the chain, rinse and apply lubricant (see Table 2) or remove the right crankcase cover and, turning the rear wheel, apply lubricant to the chain. When assembling the chain, connect the links with a lock, set the latch with a cut in the direction opposite to the movement of the chain (Fig. 28).
Check the chain tension by pressing the lower rubber chain cover up and down in the middle of the chain cover (fig. 28). When moving the chain over 30 mm, tighten it by changing the position of the rear wheel axle with nut 3 (Fig. 29). After adjusting the chain, tighten the nuts of the axle shaft, axle and guy wires. In the case of a large stretch of the chain, shorten it by two links using the connecting link and the tool from the kit. When adjusting the chain, make sure that the wheels are in the same plane. Adjust the wheels in one plane according to the risks on the pendulum fork and the projections of the chain braces. After adjusting the chain tension, be sure to adjust the rear wheel brake.
Figure: 29. Adjusting the chain tension:
1, 2, 3. nuts; 4. lock nut
Maintenance of the speedometer gearbox consists of lubricating the gears. To do this, remove the disc brake cover, unscrew the bolt, take out the flexible shaft, the gear sleeve. Rinse and lubricate parts. Assemble in reverse order.
The electrical diagram is given in Appendix 6. The electrical equipment of the motorcycle includes:
sources of electricity. storage battery and generator;
control device. voltage rectifier-regulator;
ignition devices. ignition coil, sensor, switch and spark plug;
lighting and signaling devices. headlamp, rear lamp, direction indicator lamps, sound signal (for a motorcycle with a side trailer, an additional front marker lamp and a rear lamp);
control and monitoring devices. ignition switch, warning lamps, turn signal interrupter, light mode switch, horn switch, direction indicator switch, light mode switch, high beam warning switch, emergency engine switch, front and rear brake light switch.
Alternator (Fig. 30) single-phase alternating current with excitation from permanent magnets.
The rotor of the generator is mounted on the cone of the right half-axis of the crankshaft of the engine, the stator is in the cover of the generator or on the base fixed in the crankcase. The stator has two separate windings: charging and power. The charging winding is connected directly to the commutator and serves to power the engine ignition system, the power winding through the rectifier-regulator provides power for lighting devices, signaling and charging the battery.
Figure: 30. Generator and ignition sensor:
1. rotor; 2. stator; 3. ignition sensor
The ignition system is powered by alternating current, the rest of the consumers. through a rectifier-voltage regulator with direct current.
The generator does not have sliding contacts and rubbing parts, its maintenance is reduced to monitoring the state of electrical insulation, wire connections and the reliability of the rotor and stator fastening.
The serviceability of the generator set (generator-rectifier. voltage regulator) is checked using a DC voltmeter with a scale division of 0.1 V. The voltmeter is connected to the “” terminal of the rectifier-voltage regulator and “ground”. At medium engine speeds with the battery connected and the headlight high beam on, the voltage should be 13.7. 14.7 V. Voltage deviation from the specified values indicates a malfunction of the rectifier-voltage regulator or generator.
Remove the generator from the engine in the following order:
disconnect the generator and ignition sensor wires from the rectifier-voltage regulator, switch, main harness;
remove the cover of the generator with the stator, unscrew the four screws securing the stator and the screw of the bracket for fastening the wires to the cover of the generator, disconnect the stator from the cover of the generator;
unscrew the rotor mounting bolt, using as a puller the screw from the tool for squeezing the chain link axle (screw it into the rotor shaft), remove the rotor.
If the stator is installed on a base fixed in the crankcase, unscrew the four screws securing the stator to the base, remove the stator with a harness.
Install the generator in reverse order.
The battery is the power source when the engine is not running. The “-” terminal of the battery is connected to the “ground” of the motorcycle. Reverse connection of the terminals is unacceptable, as it leads to failure of electronic devices, other electrical equipment and the battery itself.
The actuation, operation and maintenance of the battery are described in the enclosed battery instruction manual.
Parallel to the battery, a 2200 microfarad capacitor is connected, designed to smooth out the ripple of the rectified voltage and ensure the normal operation of the motorcycle’s electricity consumers in the event of a battery failure or its absence.
General conditions for the selection of a drainage system: The drainage system is selected depending on the nature of the protected.
Transverse profiles of embankments and foreshore: In urban areas, bank protection is designed taking into account technical and economic requirements, but attaches particular importance to aesthetic.
Papillary patterns of the fingers. marker of athletic abilities: dermatoglyphic signs are formed at 3-5 months of pregnancy, do not change during life.
Single-column wooden support and ways to strengthen the corner supports: Overhead line supports. structures designed to support wires at the required height above the ground, water.