How disc brakes are adjusted on a bicycle

Disc hydraulic brakes

disc, brakes, adjusted, bicycle

Hydraulics are used to create a wide variety of mechanisms. Its high efficiency is primarily due to the non-compressibility of the liquid.

The following points are called features:

  • The main advantage is the ease of braking and the softness of the system used. In this case, you can feel the pressure force, which increases towards the end of the handle stroke. In comparison with the mechanical type of the device, the considered one is characterized by a smoother stroke of the handle. Therefore, there is no need to apply a lot of force for braking.
  • The hydraulics can withstand long-term use. This is due to the fact that it is less prone to overheating. Therefore, braking can take place for a long period even when driving downhill.
  • Device adjustments are carried out much less frequently. That is why you can remove the wheel for cleaning or replacing it.

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

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.

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 Stop Your Disc Brakes Rubbing

  • 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.

The main differences between hydraulic and mechanical disc brakes

The main difference between the hydraulic and mechanical types is the principle of transferring the force exerted on the handle to activate them. So, if a cable serves as a conductor of the pressure force in mechanics, then in hydraulics it is a liquid. Both brake and mineral oil (depending on the manufacturer) can be used as a fluid. Both of them are good in their own way, and their effect differs from each other to a small extent. The photo shows a schematic representation of the device of the hydraulic type of disc brakes.

Photo: the main elements of the hydraulic system of disc brakes

Disc Brakes. Basic Adjustment. by Northrock Bikes

How to set up disc brakes on a bicycle

Running a bike is one thing, but fixing it is another. Even skilled and experienced cyclists are faced with the problem of incorrect / defective disc brakes. You can deal with this phenomenon if you clearly know the principle of operation and the structure of the system. And you should start with these main points.

Setting up mechanical disc brakes on a bicycle

In cases where one of the elements of the brake system fails, which makes it necessary to replace it, adjustments should be made. There are several sequential steps that will help you cope with this task efficiently and quickly:

  • We check all fixing elements (bolts). If one or more of them are not tightly screwed in, then they lose their functional purpose.
  • We unscrew (not completely, but only in order to loosen the fixation) the lock nut, after which we tighten the cable tension adjuster on the steering wheel. We bring the locknut to the previous position (fix). With the adjustment located on the caliper, we perform the same actions. Pull the cable by hand after loosening the lock. When the required tension is reached, screw the retainer back.
  • Dismantle the car.
  • As you know, one of the pads is motionless, and the other is vice versa. It is important to achieve an equal distance from the center of the caliper slot for proper rotor positioning. The fixed block is adjusted with a lock nut. By loosening it, you can move the position of the element as much as necessary. The movable block is adjusted by rotating the cable tension adjustment on the caliper. Having reached the desired position, we fix the non-static block.
  • We adjust the caliper. It must be aligned exactly in relation to the rotor.
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That’s all you are done. It often happens that the rotor still rubs against the block when moving. This is not surprising, because it is not always possible to align the pads themselves exactly. Determine which one is not fixed correctly (just push the bike and see, this will be enough) and adjust the desired one as described in the instructions above. But sometimes the cause of friction is rotor deformation. To do this, it must be aligned. If the flaws are too serious, it is better to replace.

Things to do before adjusting the brakes?

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 hydraulic disc brakes

Hydraulic bike brakes are positioned as self-adjusting, requiring no intervention or adjustment. But you still need to set them up from time to time. For example, if you hear strange creaks or rustles during operation, or the factory settings are initially incorrectly set. The following few steps will help you quickly and efficiently set up your hydraulic disc brakes:

  • The bolts fixing the caliper on the adapter must be loosened.
  • Squeeze the brake lever and fix it in this position (if there is no assistant, use the materials at hand: electrical tape, fishing line, wire).
  • We carry out a visual inspection. As with a mechanical system, the rotor should be positioned clearly in the middle of the caliper slot, with pads equidistant from it. If the rotor is not positioned correctly, align it by pressing in the direction where the unevenness is noticed. This will contribute to an even distribution of liquid and fixation in the desired position of the pads and rotor.
  • At this point, the adjustment can be considered complete, and you just have to fix the mounting bolts and return the handle to its original position.

As with mechanics, hydraulics also have a rotor that performs the same function. Sometimes it can give in to deformation. But this can be eliminated by determining the place of the bend and bending it in the opposite direction. Then the shuffling sounds when driving will stop.

Advantages and disadvantages of mechanical brakes

Mechanical brakes are cheaper, cables and casings (jackets), in which they are located, are quite reliable, more accessible than hydraulic lines. It is also important that the repair of a mechanical brake in the case of a bent disc is easy to carry out on your own.

Mechanical disc brakes

Mechanical brakes are more common. They are installed on almost all bicycles today.

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This is due to the points below:

  • They are much cheaper due to design features. Steel with high corrosion resistance is used in the manufacture of the cable. The length is selected depending on the characteristics of the bike.
  • The main elements: cable and sheath, are characterized by higher reliability. The use of steel in their manufacture determines a high degree of resistance to mechanical stress.
  • In the event of a malfunction, it is possible to carry out repairs yourself. All system elements are characterized by a simple design. Therefore, there are no serious difficulties with the repair.

It should be borne in mind that every time after removing the wheel, you have to adjust the system. In addition, the cable has to be lubricated from time to time to ensure the required level of efficiency at the time of operation.

Device and principle of operation

The difference between the principles of operation of disc and mechanical brakes is insignificant. But, there are still differences in their device. Let’s consider step by step, starting with the mechanical type, which is arranged as follows:

  • Brake handle. It is fixed on the steering wheel, for the convenience of squeezing, with a clamp. It is designed to transfer force to the brake pads, bringing them into action.
  • Cable adjuster with lock nut. The first element serves as a regulating device for limiting the cable tension. The second is for fixing the regulator itself.
  • Brake lever adjuster designed to determine a comfortable distance to the handlebars.
  • Cable jacket. protecting it from dirt, mechanical damage.
  • To fix the cable, a clamp in the form of a bolt is used, with the possibility of adjustment
  • The mechanism that allows the cable to be set in motion, when pressed on it, is called a caliper. Its action is not possible without brake pads. rubber or metal fragments that ensure a tight clamping of the disc.
  • Directly disc (rotor). It locks onto the wheel hub.

Figures 1 and 2 show schematically all of the above details.

Figure: Bicycle brakes

Figure: appearance of the brake lever with main elements

How to set up disc brakes on a bicycle

Running a bike is one thing, but fixing it is another. Even skilled and experienced cyclists are faced with the problem of incorrect / defective disc brakes. You can deal with this phenomenon if you clearly know the principle of operation and the structure of the system. And you should start with these main points.

How to release the disc brake on a bicycle

It is enough to screw in the cable tension drum a certain number of revolutions. If its stroke is not enough, unscrew the nut securing the cable to the caliper and loosen its tension. Option “so-so”. unscrew the handle adjustment bolt.

Don’t forget about the fixed shoe. Moving away the movable friction pad with a cable, move the static one, so that symmetry with respect to the rotor is maintained.

Things to do before adjusting the brakes?

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.