How To Adjust Rear Disc Brakes On A Bicycle

Check the condition of the cable and shirts

This item is intended solely for mechanics. Before adjusting the mechanical disc brakes on your bike, you should carefully check the condition of the cables and shirts. If the cable is damaged, namely, if it is fluffed, broken individual fibers are observed, then it should be replaced without fail. It doesn’t matter if the cable changes or not, it must be lubricated before adjusting the brake. We also inspect the cable jacket. If cracks or tears are visible on it, then it is better to replace it.

How To Adjust Rear Disc Brakes On A Bicycle

Check rotor

First of all, we unscrew the brake rotor from the hub and check it for deformation. This can be done by placing it on a flat surface (glass, mirror, etc.) and inspecting it. If the rotor is loose, it should be aligned before adjusting the disc brakes. If the deformation is insignificant, then this operation can be performed when adjusting the brakes.

How to set up mechanical disc brakes on a bicycle

Adjustment of the disc mechanics is required to be done: after installing new pads, cable, rotor or other brake components; in the case when the rotor rubs into the pads when it is required to eliminate the large travel of the brake arm, etc.

  • We check the tightness of the bolted joints at the points of attachment of the adapter to the frame and the rotor to the bushing.
  • Loosen the lock nut and tighten the cable tension adjustment on the steering wheel until it stops minus 1-1.5 turns. Then tighten the lock nut. We do the same on the adjustment located on the caliper. Next, unscrew the cable lock, and, pulling the cable by hand, tighten the lock bolt back. (If you have already done these operations when installing a new brake, then you do not need to repeat these actions).
  • Loosen the bolts that attach the machine to the adapter (for easier adjustment, you can remove it completely).
  • We adjust the position of the fixed (static) and movable shoe. The purpose of this procedure is to achieve an equidistant position of the pads from the center with the caliper slots, so that the rotor can fit between them with minimal gaps. To adjust the fixed shoe, loosen the locknut (if any), and rotate the bolt, which adjusts its position. To adjust the movable one. we rotate the adjustment of the cable tension on the caliper. After the distance is set, tighten the static block retainer. If for this procedure you removed the machine, then you should install it in place, but do not tighten the mounting bolts.
  • We set the correct position of the brake disc caliper. For this, the bolts that fasten it to the adapter must be loosened so that it can easily walk left and right. We press the brake lever all the way and fix it with electrical tape, wire, rope or other improvised means. Next, slightly wiggling the caliper with your hand, screw it to the adapter, alternately tightening the bolts.
  • After performing the above operations, in 80% of cases the rotor will shuffle into the log (s). We determine which of them it clings, and adjust the distance by adjusting the cable tension on the caliper (in the case of friction in the movable block) or by rotating the bolt (if rubbing against the static one). The clearance on both sides should be minimal, at which the rotor does NOT touch the pads.

You can see the detailed setup process for mechanical disc brakes on this.

There are cases that after adjusting the mechanical disc brakes of a bicycle, the rotor “strikes” into the pads in one (or several) places. This suggests that you have it slightly deformed. In this case, you need to align it. This can be done directly on the bike without removing the rotor. Determine the place where it touches the pads by slowly rotating the wheel. Pay attention to which side the rotor is deformed. Then, we turn this section so that access appears to it, and we bend it in the opposite direction from the place of friction. Be careful not to make it worse. Do not put too much pressure on the rotor. It is better to repeat this operation several times to smoothly add the pressing force.

Check the condition of the brake hose for leaks

This item is exclusively for hydraulics. Before adjusting the bicycle’s hydraulic disc brakes, we will inspect the brake hose for damage (it is advisable to replace it, even if the damage is minor), and also check that there are no oil / brake fluid leaks at the joints of the hydraulic line with the caliper and the master cylinder. Another place where the brake fluid can poison is the rod going from the brake lever to the piston (if the cuffs are leaky). Well, after removing the brake pads, check for leaks on the caliper.

What to do before adjusting the brakes

If you need to adjust disc brakes that have already been in operation for some time, then before making the adjustment, it is advisable to perform the following preparatory work:

Bicycle disc brakes

Disc brakes are designed to brake a bicycle by converting kinetic energy into thermal energy by rubbing the pads against the brake disc. As mentioned earlier, bicycle disc brakes are mechanical and hydraulic. Their principle of operation is the same, but there are slight differences in design.

Disc Mechanical Bicycle Brakes

Disc mechanics is of the following design.

  • Brake handle. It is mounted on the handlebars (attached with a clamp) of a bicycle and is designed to transfer the force of pressing the hand to the brake pads.
  • Cable adjuster with lock nut. The cable adjuster is designed to change the tension force of the cable of mechanical disc brakes. Locknut. for fixing the regulator.
  • Brake lever adjuster. Allows you to adjust the distance from the brake lever to the handlebars, thereby making it possible to set a comfortable position directly under the length of the cyclist’s fingers.
  • Cable shirt. Serves to protect the cable from damage and dirt.
  • Cable. Required to transfer the movement of the brake lever to the brake caliper.
  • Cable holder. The place where the cable is attached and clamped with a fixing bolt.
  • Caliper. A mechanism that activates the brake pads when the cable is pulled.
  • Brake pads. They are metal platforms with an organic or metallized substance applied to them. Inserted into the caliper.
  • Adapter. Serves as a kind of layer between the caliper and the bike frame.
  • Rotor (brake disc). Mounted on the wheel hub.

How to set up and adjust disc brakes on a bicycle

Many riders who are first faced with hydraulic or mechanical disc brakes on a bicycle do not know how to properly set, adjust or replace consumables. Many people think that their design is much more complex than that of a V-brake. But it is not so. Technological, good bicycle disc brakes, especially if they are hydraulic, are more advanced than you break and do a lot better at their job, but remember that this is NOT a cheap mechanic. Next, we will look at how to properly install and adjust disc brakes yourself at home. But we will start with the design features and differences between disc mechanics and hydraulics. And then we will touch on all of the above points.

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Disc Hydraulic Bicycle Brakes

Disc hydraulics are very similar to their mechanical counterparts. The main difference is that the force applied to the brake lever is transferred to the pads not by the cable, but thanks to the DOT4 brake fluid (on Avid, Hayes, Helix brakes) or mineral oil (on Shimano brakes). Next, consider the design of hydraulic disc brakes.

  • Brake handle. Actuates the piston, which presses on the brake fluid.
  • Brake lever adjuster. As in disc mechanics, it is designed to adjust the position of the handle of the steering wheel.
  • Master cylinder. It consists of several parts. An expansion tank with a lid serves as a brake fluid storage. The cap is used when filling and bleeding the brakes. Inside there is also a piston with a cuff and a return spring.
  • Hydraulic line. It is a durable hose that connects the master cylinder and the caliper.
  • Caliper. A mechanism that, when pressure appears in the hydraulic line, activates pistons that push the brake pads.
  • Brake pads. They serve to convert frictional force into thermal energy, thereby stopping the bike.
  • Adapter. The part that attaches the brake caliper to the fork or bike frame.
  • Rotor. It is a perforated metal disc, in which, when the handle is pressed, the pads rub.

Disc mechanical brakes

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

Instructions for setting up disc mechanical 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.
  • It is 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, squeeze the handle to the end, after which it should be fixed in this position. Next, the correct centering of the disc machine 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 a shift.

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

How to adjust disc brakes on a bicycle?

The disc brake system has a simple design that can last for a long time. Such an embodiment is much cheaper and is characterized by high efficiency in application even with increasing environmental humidity.

Disc brakes are of two types: mechanical and hydraulic. Both options have their own characteristics, in which we will talk in more detail below.

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, through which energy is transferred from the handle to the executive unit. In this case, a high force can be transmitted.
  • Hydraulic Represented by the line through which the fluid transfers energy to the brake pads.

Disc mechanical brakes

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

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: wire rope 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 elements of the system 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, it is necessary to lubricate the cable from time to time to ensure the required level of efficiency at the time of operation.

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.

Disc hydraulic brakes

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

The following points are called features:

  • The main advantage lies in 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 device, the considered one is characterized by a smoother stroke of the handle. Therefore, it is necessary to apply great force for braking.
  • The hydraulics can withstand long-term operation. This is due to the fact that it is less prone to overheating. Therefore, braking can last for a long period even when driving downhill.
  • Device adjustments are performed much less frequently. That is why you can remove the wheel for cleaning or replacing it.

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 becomes a prerequisite for low efficiency.
  • All damaged items Must be replaced. An example is a frayed cable or a damaged hydraulic line. Do not forget that some elements may wear out over time.

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

Disc hydraulic brakes

In such cases, the reason for 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:

  • The bolts are unscrewed on the caliper, after which the handle is squeezed out to press the pads to 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 such a position, the pads 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. To solve the problem, you can press one of the pads, after which the handle is worked through 10 times. By such actions, unevenness is eliminated.

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

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Caliper brakes

Used exclusively on road bikes. Although a more simplified design of caliper brakes can be found on children’s bicycles. They differ from vibracks in that both brake levers are attached to the frame with a single screw. All adjustment comes down to setting the gap between the pads and the rim using the tension on the cable. The most popular brands are Shimano, SRAM and Campagnolo.

Disc brake adjustment

First of all, it is worth checking if the rotor is damaged. If it has chips and burst areas, then no adjustment will help. the brakes will still not work correctly. In case of a damaged rotor, it will need to be replaced.

As for the types of disc brakes, they are mechanical and hydraulic. The latter are put mainly on high-end bikes, because they cost a lot. The only difference between the adjustment of disc hydraulics and mechanics is the work with brake fluid. Before winter, for example, it will need to be drained a little. This will help increase pad free play.

In disc brakes, it is most often required to adjust the angle of pressing the pads against the rotor. Do not forget that first of all they must be strictly parallel to each other.

So, the brake pads on disc brakes are located in the caliper. this is a special device that is attached to the frame and to the bicycle fork using an adapter. To adjust the caliper and pads Follow the steps below.

  • Take the wheel, and fix it in the position that you will use directly for driving.
  • Next, you need to see how the caliper works, for this you should loosen the screws fixing it a little.
  • Now you need to press the brake lever to see how the caliper “goes” and returns to its place. Also remember to check the clearances.
  • Then it remains to tighten the machine, and fasten the screws one by one. that’s the whole setting.

Also, when adjusting disc brakes, you may need to adjust the length of the retaining cable. This is done in the same way as with rim brakes. The mount is untwisted, then the cable is released, shortened or lengthened, the mount is screwed back.


About bicycle disc brake repair

You can learn even more from the article.

Setting up and installing hydraulic brakes on a bicycle is done in the second way, you will learn about this here.

Disc brake creaks

? Find out how to get rid of this problem:

Step number 1. determine the type of brakes

The type of brakes fitted to your bike depends primarily on your riding style. Let’s figure it out on Clear examples.

  • Foot. They are installed on the simplest city models, and on almost all walking bike models, for example, cruisers. Such brakes are very simple in structure, effective and reliable. Also, and most surprisingly, the foot brakes do NOT need to be adjusted at all. They have one peculiarity: the longer you use them, the more effort is needed for effective braking. This is, by and large, the only problem that can arise with such brakes, and it is solved by replacing the internal pads. This should be done by a master, it is not recommended to disassemble the brakes himself. there is a risk of wasting time in vain and gaining a lot of nerves, after which you still have to contact the master.
  • Rim. They are put on walking fables, city, road, highway, mountain and even bicycles for jumping. They are very simple in design, efficient, reliable, and most importantly, they weigh little. That is, despite the insignificant moral obsolescence, rim brakes continue to be used all over the world. Their only drawback is that with prolonged use, the wheel rim is depleted, which leads to its destruction. Disc brakes look like this: two handlebars on the steering wheel that receive pressure, a system of cables, and two small mechanisms with pads on each wheel. they are given force, after which an effective action occurs, that is, braking.
  • Disc brakes. The most progressive of all the varieties that exist today, they are superior to rims in everything, with the exception of two parameters. they weigh more and require the installation of a special rotor on the drum, which makes it impossible to install, for example, a trunk. In general, disc brakes are the most effective ones and are used by professional riders. they allow you to control the ride as efficiently as possible. Therefore, disc brakes are used on high-end mountain bikes, as well as on bicycles for EXTREME riding. it is impossible to come up with something more effective. Due to the braking through the rotor, the wheel rim does NOT suffer at all, and the very condition of the wheel does not affect the braking at all. The last disadvantage of disc brakes is that they require powerful spokes from the bike, because the braking force is transmitted from the rotor through the spokes to the wheel.

Within the framework of a specific article, we will talk about rim and disc brakes. these are the most common types, besides, they really need regular adjustment, which cannot be said about the foot brake. But before that, we’ll figure out how to tell if the brakes on your bike really need tuning.

Setting v brake rim brakes

Today, mountain bikes are widely used with v-brakes, so here’s an example of how to adjust the brakes of a bicycle in the case of a rim brake. Setting up the second rim brakes is done in the same way. The only difference will be that the bolts and screws, which need to be twisted, may be in other places. And the approach is the same (even in the case of disc brakes).

So, the basic rule is that the pads should be parallel to the rim. The clearance between the shoe and the rim should be 1 mm. And both pads must be symmetrical.

How to set up disc brakes on a bicycle, set the brake pads correctly

Cantilever brakes

Their mechanism consists of two levers with brake pads attached to the pivot 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 supplanted by other second types of brakes with more effective braking force.

Caliper brakes (C-brake)

Most often used on road bikes, but there they are gradually being replaced by other types of brakes. The name of the brakes speaks more eloquently in its design: the brake pads are pressed against the rim by curved levers, which outwardly resemble pliers.

Disc mechanical brakes

The most popular manufacturers of such brakes are Tektro, Shimano, Avid. The braking force is transmitted in a similar way, but not to the rim, but through a cable and a mechanism called a caliper, to a special brake disc (rotor). The caliper has brake pads made, as a rule, of metal or synthetic materials. One shoe is usually stationary (internal), the other (external), during braking is pressed against the rotor and presses the rotor against the fixed shoe. However, there are also systems with two movable pads. These brakes are usually found on mountain bikes.

Setting up THESE brakes usually boils down to the correct (parallel) installation of the caliper to the rotor and setting the clearance between the pads and the rotor using adjusting devices on the caliper. The simplest brakes may not have such adjusting elements. In this case, the caliper is installed so that the inner (stationary) shoe is as close to the rotor as possible (a gap of 1-1.5 mm), and the outer cable tension is adjusted.

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The main disadvantage of this braking system is the need for frequent adjustments as the pads wear out.

Disc or rim brakes: which is better?

Most likely, no one will doubt that brakes are one of the most important parts of a bicycle. The health and life of not only the cyclist himself, but also all participants in the movement directly depends on the correct operation of the brake system. Therefore, it is logical to conclude that when buying a bicycle, you need to choose a reliable model with a strong braking system, which will allow you to stop the bike in a short period of time in an emergency on the road, regardless of weather and road conditions. However, when choosing a bike, you can easily get confused about the variety of braking systems, their characteristics and recommendations. Therefore, it is worth first to figure out what braking systems exist, and also to compare the advantages and disadvantages of one or another braking device.

Types of bike brakes.

Every day, technology, as well as bicycle parts, are improving. Therefore, the types of brakes that were used before may no longer be installed on modern bicycles. In this regard, we will only talk about two main types of brakes.

1. Rim brakes

  • Mechanical (cable and cable jacket are used for compression).
  • Hydraulic (hydraulic line and brake fluid are used for compression).

2. Disc brakes

  • Mechanical.
  • Hydraulic.

Sometimes bicycles with a mixed braking system (hybrid) can be found. For example, the front wheel may have a disc brake, and the rear wheel may have a rim.

Which brakes are better: rim or disc? Rim brakes

All rim brakes have a common disadvantage: the wheel rim is damaged during braking. In case of severe damage, when the wheel is twisted into a “eight” or “egg”, it is impossible to use the mail brakes. Also, in rainy weather, braking is uncertain, due to wet pads and wheel rims. It is necessary to constantly monitor and adjust the brake as the pads wear off.

However, rim brakes have been successful and are very frequently installed as they have a number of advantages such as ease of maintenance, affordability, and low weight and part compatibility.

Mechanical rim brakes include tick and cantilever brakes. Caliper brakes consist of pads, which are attached to arcuate levers, when braking they compress the wheel rim, thereby reducing the speed of its rotation. The brake cable drives the levers and is conveniently attached to the handle on the handlebars. The plus is that the caliper brakes are generally available and easy to operate. The disadvantages are that such brakes are often skewed, creating NOT the necessary friction on the rim, they quickly become dirty and are noted for mediocre modulation.

Cantilever brakes are very common on mountain bikes. The operation of the cantilever braking system is very simple: two levers with pads are attached to the fork using two special mountings. When you press the brake lever on the handlebars, the cable starts to pull these levers towards each other, thus pressing them against the rim, creating friction and braking of the wheel. The main advantage of this type of brake is the complete absence of the possibility of clogging the brake system with dirt.

Hydraulic brakes differ from mechanical brakes in that there are no levers, which are attached to the pads, as well as cable systems that operate the levers. The principle of operation of the hydraulic system is quite simple: a handle with a master brake cylinder is attached to the handlebars, when pressed, pressure is transmitted to the other brake cylinders, attached to the bicycle fork. The created pressure forces the brake pads to move towards the wheel rim, which leads to braking. It should be noted that such a braking system is very effective and is often used in trials. However, hydraulic brakes are heavy, difficult to maintain, and difficult to repair while hiking.

You should also pay attention to the V-brakes, which are popular and widely used lately. They are very similar in appearance to cantilever ones, however, they have a significant difference in the principle of operation. Due to the specific attachment of the cable to the levers, the braking power of the bicycle increases. They are easy to maintain and reliable, also light in weight and thanks to the system of parallel supply of pads to the wheel, they wear evenly and contribute to better braking. When buying a bike, you need to check that the brakes are adjusted, and then regularly check their serviceability.

As for drum or roller brakes, they are located directly inside the hub itself in the wheel motionlessly, and when braking they are pressed against the rotating part, reducing the speed. These brakes are quite simple and are NOT afraid of dirt or dust. However, in the event of a malfunction, they are very difficult to repair and heavy, therefore they are rarely used on hikes.

Disc brakes

This type of brake has recently become more common and practical for bicycles. Disc brakes are simple in structure. They consist of a disc, which is attached to the wheel hub, a caliper, which is attached to the fork or frame and a cable (mechanical system) or a hydraulic tube (hydraulic system), by means of which the caliper is connected to the brake lever.

When buying a bicycle with a disc brake system, you can be sure of high braking efficiency, you will not need to worry about the condition of the wheel rim, trips should never be affected by weather conditions, they DO NOT need constant maintenance and tuning and have a long service life.

By choosing a bike with a mechanical brake system, you can significantly save on the purchase. The structure of such a system is very simple and looks like a pick-break type brake. Here, a simple cable is used to connect the caliper and brake lever. However, you should consider not only the pros, but also the cons. The disadvantage is that the cable can stretch over time, and this creates the possibility of the cable jamming in the shirt. However, despite this, they are very easy to repair in any conditions, cost less and are well suited for any hiking trip.

If the budget allows, then you can purchase a bicycle with a hydraulic braking system. Here, braking is carried out by transferring the braking force from the brake lever to the caliper using an incompressible brake fluid, which is located in the high-pressure hose. This type of braking system is very efficient and highly modulated. A bicycle with a hydraulic disc braking system is great for professional mountain bikes. But the disadvantages of THESE brakes should also be taken into account, among which their high cost and difficulty in setting up, which requires Special tools and experience, come to the fore.

Finally, it remains to look at bicycles with a hybrid braking system. Such bicycles are very rarely found on sale, because they are high in price and disc mechanics in this case do not win much over other brake systems.

Of the braking systems discussed, hydraulic disc brakes are of course the most highly efficient. However, the conditions and frequency of bike use need to be considered before purchasing. And only after that, make a decision with what type of braking system you want to deal with, and what of this budget allows you.