Setting up rear disc brakes on a bicycle

Things to do before adjusting the brakes?

setting, rear, disc, brakes, bicycle

The brake system is adjusted periodically. Due to this, a long service life as well as high efficiency can be ensured.

The main recommendations are the following:

  • To begin with, the state of the main elements of the system is checked. This recommendation is due to the fact that even minor damage results in poor performance.
  • All damaged items must be replaced. An example is a frayed cable or a damaged hydraulic line. Do not forget that over time, some elements may wear out.

If the brake system does not have serious defects, then you can start adjusting it.

Adjusting and adjusting disc brakes on a bicycle

Despite the fact that the design is quite simple and reliable, it has to be adjusted from time to time.

This is done for the following reasons:

  • To ensure long-term performance.
  • High efficiency enhancements.

Bicycle disc brake design

In many ways, it is the design of the disc brakes that determines how tuning is done.

All devices fall into two categories:

  • The mechanical device has a cable, due to which energy is transferred from the handle to the executive unit. In this case, a high force can be transmitted.
  • Hydraulics are represented by the line through which the fluid transfers energy to the brake pads.

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 process of their maintenance will depend on what type of brake system is installed on a particular bike.

Mechanical disc brakes

Mechanical brakes are recommended to be adjusted in case the disc rubs against the pad. In addition, adjustment is required in the event of a weakening of the braking force.

Instructions for setting up mechanical disc brakes are as follows:

  • The brake lever is squeezed out to the stop.
  • The lock nut of the machine is unscrewed, after which the regulator is turned inside out. If you need to unscrew it strongly, then you have to loosen the cable.
  • Determined what the gap between the disc and the pad. If the braking device is crooked, loosen the screws to adjust the position. They attach the device to an adapter or plug.
  • The screws that secure the brake are unscrewed.
  • Having made the caliper movable, the handle should be squeezed out to the end, after which it should be fixed in this position. Next, the correct centering of the machine relative to the disc is carried out.
  • Tightening is carried out with a screw to fasten the brake machine. Twisting should be carried out periodically, since only in this case it is possible to exclude the possibility of shear.

After that, the handle is released. Compliance with the recommendations specified in the instructions ensures the ideal position of the disc and pad.

Setting up mechanical disc brakes on a bicycle

Disc hydraulic brakes

In such a case, the reason for the adjustment is the strong resistance of the wheel at the moment of movement, as well as when an extraneous sound or squeak appears.

The adjustment instructions in this case are as follows:

  • On the caliper, the bolts are unscrewed, after which the handle is squeezed out to press the pads against the wheel.
  • The next step is to check the position of the valves. They must be equally spaced from the rotor.
  • Next, all screws are tightened.
  • After locking the caliper, the handle is released. In this position, the block should not be pressed against the rim, be at a distance of about a millimeter.
  • Quite often there is a situation where the pads are located at different distances from the rim. The problem can be solved by pressing one of the pads, after which the handle is worked through 10 times. Due to such actions, unevenness is eliminated.

The final stage involves setting the correct position of the handle, which controls the system. For this, a special adjusting hexagon is installed.

Diagnostics of the brake system

As with the human body, which functions as a whole, before fixing brake problems on a bicycle, diagnostics should be carried out to determine the extent of brake damage. After all, if the block is worn out, from which the impact on the disc becomes much worse, and there is no stopping effect (due), then only it needs to be replaced, and not the system as a whole. So, below are some of the diagnostic steps you need to take to identify the causes of your bike’s “ailment”:

How To Adjust Disc Brakes. Braking Pads Rubbing Against The Rotor. Bike Maintenance

  • Deformation of the rotor can be one of the reasons for the malfunctioning of the braking system. Therefore, removing it is a top priority. When you unscrew the clamps and remove the rotor, it must be placed on a flat surface, such as a mirror. Carefully inspect how tightly and evenly the rotor adheres to it, and if you notice irregularities, it means that they need to be corrected.
  • We dismantle the brake pads to carry out a visual inspection for damage. This action is as follows: find the extension on the caliper, and then turn the pads until they are removed. It is not difficult to visually determine the wear on their surface. So, the figure shows that the block on the right is already completely worn out and requires immediate replacement.
  • Figure: Determining Pad Wear
  • The next “candidates for close inspection” are cables and shirts. This item is suitable for those modes of transport where mechanics are used. It is necessary to check the cable for fiber breaks, deformations, and so on. As for the shirts, remember that their function is to protect the cable from negative factors (accumulation of dust, moisture). Therefore, cracks or breaks simply should not be present here. Both elements must be lubricated before installation / replacement.
  • For hydraulics, there is also a test exclusively inherent in this type of system. the condition of the hydraulic line for leaks. It is important to understand that if there are leaks in the hydraulics, the proper pressure may not be exerted on the pads, which automatically disables the system. Damage to the hydraulic lines is quite likely, which are revealed by visual inspection. over, it does not matter at all whether this damage is strong, or insignificant. It is also necessary to check the junction of the brake line, caliper and master cylinder. A rod extends from the brake lever to the piston. another potential place from which fluid can be vented in case of mechanical damage (on the cuffs). After dismantling the brake pads, it is necessary to check for leaks on the caliper itself.
  • The rotator, like the pads themselves, can get dirty while using the bike. Both oil and dust accumulate here, forming solid layers that interfere with the operation of the system. Adjusting the brakes without cleaning the rotor and pads from dirt is a mistake. Cleaning can be done with fine-grained sandpaper. But for this you need to dismantle both parts so that the cleaning is done as efficiently as possible.
  • The final is wheel adjustment. It should not be skewed to the side in any way. You can check this simply by placing the bike on a flat surface and performing a visual inspection. If the wheel is tilted to the side, it must be aligned (loosen the eccentric, then adjust the wheel).
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A set of such activities is required. All this can be done quickly enough if you have all the necessary tools (screwdriver, wrenches). Next, we go directly to the processes of adjusting and installing the brakes.

Varieties of rim brakes

Rim brakes are divided into several types:

  • tick-borne;
  • cantilevers;
  • 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 with attachment 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 mounts of the arcs.
  • 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 unclamping 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 work is to extend the levers under the action of a taut leash. The principle of operation of the cantilever brake:

  • 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.

In justification of the latter, it should be noted 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 connected to each other by a pulling cable. The drive cable is brought to one side, but due to the straight shape of the “tie” forces are equally transmitted to both levers.

Hydraulic bicycle rim brakes are a more advanced mechanical design. 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, move the pads towards each other.

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Advantages. high compression force and efficiency, excellent modulation. Disadvantages. deterioration of work with a blockage of the hydraulic line, complex 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 check and adjust the brakes

There are clear instructions for checking and adjusting the brake system of a bicycle. If you stick 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. Honor has one caveat. if the brake lever touches the steering wheel, then you just need to pull the cable. The operability of the rear wheel brake system is checked in the same manner. To tighten 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 setting of the brake system for rim and disc type is different, since different rotating mechanisms and pads are used.

How to install and adjust the V-brake yourself

  • 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 with the levers and put the spring.

After installation, you will definitely need to adjust the brakes.

The accuracy of the mechanism depends largely 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 terms of efficiency. What needs to be done to adjust the brakes?

Adjust the cable tension. After adjusting, the brake should instantly respond to the squeeze of the handle and rebound when it is released. If the pads do not move away from the rims, this indicates insufficient tension. On the overtightened 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 handlebar corresponds to the thickness of the finger.

If damage is 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 rigid material are placed strictly parallel to the surface of rotation of the wheel.

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.

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.

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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 there is one caveat to Honor. 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, 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 is easy to make a mistake.

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 process of their maintenance will depend on what type of brake system is installed on a particular bike.

Adjusting the rim brakes

Mountain bikes use a v-brake braking system. by its example, we will consider the principles of tuning, as 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 with respect 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 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 block 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 for Honor that the wheel should be braked even with the smallest pressure on 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 stops even when the brake lever is pressed slightly, then the system has been serviced correctly.

Adjusting the rear brakes on a bicycle

Adjusting the position of the pads

“Fasten” the brake by squeezing the levers and placing the cable guide (C) in the stop (D). Loosen the block fixing bolt (K) with a hexagon. We press the lever with the block to the rim and set the block so that it:

  • adhered to the rim with the entire surface
  • did not touch the tire
  • located parallel to the rim

In this position, the block must be fixed by tightening the bolt. When tightening the bolt, the block may move and must be corrected. It will be easier if you find an assistant who will grip and hold the brake lever while you tighten the bolt.

If your brakes squeal, try the following.

Before tightening the bolt, place a folded sheet of paper under the rear (in the direction of travel) of the shoe, then tighten the bolt. So the pads will be smoother to press against the rim when braking (first by the front, then by the rear) and will not “creak”.

We do similar operations with the second block.