Mechanical Disc Brake Installation and Adjustment
How to set up the brakes on a bike
How to set up the brakes on a bike
The question of how to set up disc brakes on a bicycle is extremely rare for owners of respective vehicles. Unlike rim pads, which require preventive maintenance at least once a season, disc adjustments are performed much less frequently, usually no more than once every 2-3 years. Except in cases of prolonged downtime and obvious signs of incorrect operation. Here, surgical intervention with subsequent adjustment measures is simply necessary.
Experienced cyclists are familiar with the list of reasons for a faulty braking system or situations where additional adjustment is indispensable.
The main reason for incorrect operation is worn out pads. Buying a new vehicle is always accompanied by its individual adjustment. If you become the owners of a brand new two-wheeled “friend”, then its mechanisms need to be run in, and also adjusted in several approaches. Cold storage, in other words, “great”, which has been in an unheated room for a long time, needs additional examination of the pads and the brake system.
Another reason to think about the health of your vehicle and its mechanisms is the appearance of extraneous sounds. Any knock, creak or whistle indicates only one thing. not all bicycle systems work properly. As a rule, problems are related to the block or other mechanisms.
Brakes that do not respond well to the force you apply also indicate hydraulic or cable problems. Mechanical damage found during a visual inspection or after a collision must be repaired in a timely manner. Even if the braking system continues to function, one should not neglect its adjustment or replacement of individual components.
The open mechanism of the rim brakes greatly simplifies the procedure for their maintenance. Cyclists know how to set up rim brakes on a bicycle, but first you need to decide on the type of brake connection. Pads with V-Brake mount do not require special maintenance, basically manipulation with them comes down to replacing worn-out elements.
A slightly outdated type is cantilever. Unlike the V-Brake, the mechanism of this attachment has a more complex device. There is an additional cable here, it is called the central one and is responsible for connecting both sides. Another characteristic difference is the large clearance. Bikes with this system are ideal for “dirty” riding.
The caliper brakes feature a U-shaped retention mechanism. A pair of levers are connected to effectively “bite” the rim. This is the most difficult type of attachment and requires special skill to adjust it. Most two-wheeled vehicle owners are only familiar with the V-Brake type, as it is the most common.
When dismantling the brake system, observe the following sequence:
- release the brakes and, using force, remove the cable jacket from the holder;
- unscrew the mount, which is responsible for fixing to the frame;
- directly remove the brake mechanism;
- if it is necessary to replace the pads, unscrew the screw responsible for fixing them.
The last step is to remember the sequence of washers well. Usually they come in two, subsequent adjustment depends on their correct installation.
The rim brake pads are renewed or replaced depending on the degree of wear. For renewal, it is enough to degrease the surface of the contacting elements, and remove a small layer of rubber that has become unusable. For replacement, it is necessary to remove the fixing screw and pry off the old shoe and then replace it with a new one. Even if the new thing did not fit in size, do not rush to despair, the parameters are easily “adjusted” with a knife, provided that you are not holding a cartridge column.
After a successful replacement, you can start adjusting. The rim brakes are adjusted by changing the pad mounting geometry and cable tension. To do this, use a special screw, which is located on the brake lever. Excessive cable length can simply be cut. After replacement, new pads can move in any plane. The shoe should be flush with the rim, this is the correct position. In the process of checking, special attention is paid to the position of the pads; when braking, it should fit snugly against the rim over the entire area, while driving, it is parallel to the rim. If all points are observed, the screws are installed in their original position and a control check of the brake system is carried out.
It is more difficult to set up hydraulic brakes on a bike. They are practically not found in the modifications of the budget segment, rather it is a companion of a professional vehicle. The main feature of the hydraulic system is the use of brake fluid, otherwise working with it will not cause any particular difficulties. When starting to adjust the hydraulics, it is necessary to ensure that the wheel is evenly fixed in the position in which you move on it. This step is important for the hub and rotor. The brake adjustment is based on the caliper. First you need to loosen the bolts, the caliper should be movable, but not fall. Then squeeze the brake lever. the caliper will be in the desired position. At the final stage, you should check the clearances, tighten the bolts.
In addition to adjustment, the disc brake rotor needs to be replaced or straightened. If the defect is not strong, then replacement can be avoided by tightening the crooked place with an adjustable wrench. The disc mechanism is characterized by a high sensitivity to oily agents, therefore, cleaning and adjusting the system must be carried out extremely carefully. A small amount of oil left on the fingers can get inside. Use a degreasing product to adjust the rear brake of your bike. After partial disassembly, the “large” chain and the carriage should be covered, preventing the ingress of oily liquid into the mechanism.
How to adjust disc brakes on a bicycle
The advent of disc brakes on road bikes revolutionized handling and confidence in all weather conditions, but they require proper alignment to perform flawlessly.
Tools you need to adjust your bike’s disc brakes
You will need a 5mm Allen key or T25 Torx wrench depending on your brake mounting bolts.
How to install Shimano Disc Brakes
A wide screwdriver, wide wheel lever or similar flat lever can be used to reset the brake cylinders.
Straightening a bent rotor will require a slotted rotor straightening tool or a large clean adjustable wrench.
Disc brakes provide excellent braking modulation and great power in all weather conditions. They also allow for larger tires than rim brakes and don’t care if your wheel is bent a little. However, quiet, predictable frictionless operation depends on a fraction of a millimeter of brake pad-to-rotor clearance. If the brakes start to rub, there may be several reasons, so we added a menu that will help you check all possible problems, as well as adjust the calipers themselves.
Check the correct rotor
The disc can be straightened by bending it very carefully using a rotor straightening tool or a clean wrench.
If the brake is working properly, check the straightness of the rotor by checking it for rolling between the pads. If you need to straighten it, use a rotor straightening tool if you have one, or a clean adjustable wrench if you don’t have one. Bend the rotor only very carefully and gradually so as not to bend it in the wrong direction. If you can’t see the rotor between the pads, place your bike against a light background. Even a piece of white paper on the floor will do. Make sure the rotor is firmly attached to the hub as this can cause friction as the rotor moves slightly.
Inspect the caliper
Check that the brake pistons move freely by looking through the caliper
First make sure the axles are tight and the wheels do not wobble in the frame / fork. Now pull the brake while looking at the pads on either side of the rotor. They both have to move the same amount at the same time. If only one pad moves, you need to pull the wheel out and slide the pistons back into the caliper using a flathead screwdriver, tire lever, or special piston tool.
ADJUSTMENT OF THE MECHANICAL DISC BRAKE
- Since mechanical disc brakes are more sensitive to wheel axle misalignment, bolts or cams should be tightened while sitting on the bike or pressing down on the front shock. Otherwise, in the future, making small jumps, while driving, friction of the rotor against the block may appear.
- We tighten the adapter tightly. Install the caliper using the instructions above. One of the pads is pulled out by screwing the screw half a turn, which adjusts its position.
- In Hayes brake systems, before performing this operation, you need to unscrew the locking hexagon, and after all the adjustment is completed, return to its original position.
- Gently press the caliper to the rotor so that its plane coincides with the plane of the fixed pad.
- Then, alternately tighten the caliper mounting bolts. The actions given above are carried out with the jacket and cable disconnected. Make sure that the plane of the pad does not move relative to the plane of the brake disc.
- We tighten both hexagons and return the pad adjusting bolt to its original position.
- After that, we spin the wheel, checking for friction. If there is no friction, the static block can be pushed out slightly with the adjusting bolt and vice versa.
- We press the movable block, pulling the lever to which the cable is attached. In this case, the rotor will be slightly displaced towards the static block, but slightly!
- We put the cable and the shirt in the desired position in the lever, the outer block must be pressed. Tighten the corresponding bolt slightly.
- Gently press the brake lever until the start of the working stroke, from which the cable will be in the desired position in the lever. We tighten the fastening of the cable and check for the presence of friction of the pads. We twist the adjustment on the handle a little, if the shoe rubs and vice versa.
The brakes need to be adjusted so that the adjustment on the handle is minimally unscrewed, therefore, it is better to correct the position of the cable on the caliper lever. So the thread of the handles will be protected from damage.
METALLIC BRAKE PADS
Consist of an alloy of metal-containing substances.
- more resistant to heat from friction than organic brake pads;
- work more efficiently in wet conditions;
- I have a greater resource.
- create noise;
- long grinding;
- modulation is relatively worse;
- the caliper heats up instead of dissipating heat through the rotor.
These pads are preferred by riders with a lot of weight. Suitable for use on wet tracks in mud and rain. During long descents, they retain their power, although modulation is worse with them.
They work noisily, but due to the greater rigidity of the composition, they have a tangible advantage in resource. Therefore, when starting the choice of brake pads, first of all, consider in what conditions you will use them.
HOW TO INSTALL DISC BRAKES ON YOUR BIKE
Before considering how to install disc brakes on a bicycle, let’s understand a little what a hydraulic disc brake system is.
As a rule, the component parts of a disc hydraulic brake are: a brake lever, a hydraulic line, a rotor (brake disc) a caliper (having reservoirs for brake fluid, under the pressure of which the brake pads come into contact with the rotor), an adapter by means of which the caliper is attached to the bike frame.
Hydraulic disc brakes have a significant performance advantage over mechanical disc brakes. This is due to the fact that the fluid in the hydraulic lines does not change its density, does not compress or deform, in contrast to the mechanical brake cable.
There are open and closed types of hydraulic brakes. The disadvantages of closed ones include the need for adjustment during operation.
A decrease or increase in the volume of brake fluid, for example, due to the influence of temperature, causes the need to adjust the position of the brake pads. Also, brake pads should be adjusted when partial wear occurs.
Open brakes do not have this problem. Since their design provides for an expansion tank filled with brake fluid (usually located at the brake lever). Such brakes do not require adjustments during operation.
The presence of modulation (smooth movement of the handle at the beginning of the stroke and powerful adhesion of the pads to the rotor at the end) is influenced by the number of pistons in the caliper.
When it comes to choosing a particular model, it makes sense to consult with its owner. After all, different riding styles require different braking systems.
Cross country athletes are suitable for smooth and light, in downhill or freeride. powerful and well-controlled, in dirt jumping. with good modulation and, at the same time, as light and powerful as possible.
After the first adjustment of the pads, relative to the brake disc, they themselves take the correct position. This does not apply to single piston models. They require regulation, almost like mechanical ones. For example, Hayes Sole. This model is not considered the best among hydraulic brakes.
The preliminary preparation of open type hydraulic disc brakes is as follows:
- The brake system must be filled with oil. Shimano brakes use mineral oil. Avid, Hayes, Helix brakes use DOT brake fluid.
- The process of pumping the brake consists in squeezing out air from the hydraulic lines, cylinders and brake tanks, driving oil through them.
- Then the caliper is set in such a way that the brake pads do not cling to the rotor.
- Install disc brakes on a bicycle in the following sequence:
- Fix the brake levers on the steering wheel and adjust their position using a hexagon;
- We install the rotor on the hub, put the wheel in place, tighten with bolts or eccentrics;
- We fasten the adapter firmly, it is possible to use a thread lock;
- Install the caliper, but do not tighten the hexagons, so that it “floats”.
- By pressing the brake lever, check whether the brake pads extend equally when pressed.
- Clamping the brake disc with pads, the caliper will be in place. To help him, you should try to spin the wheel back and forth.
- Tighten the bolts alternately. If the bolts were very loose, you will have to smoothly release again and sharply press the handle.
- Having pressed the caliper, you need to sharply push the handle 15-30 times to bring the pads to the brake disc at the working distance.
- With the handle released, we spin the wheel and check if there is any friction of the rotor on any of the pads. If there is, you need to loosen the clipper bolts and move it slightly towards the rubbing block.
- Then we tighten the bolts back and check if there is a need, we repeat the above steps.
V-BRAKE BRAKE PADS
Disposable. their design consists of a bolt with spacer washers of a metal plate and a rubber base. They have small lines of operation, but also inexpensive.
Cartridge. their design consists of a bolt with spacer washers of a metal plate and cartridge pads, which are removed by pressing the cotter pins. The rubber base can be replaced.
There are pads for both dry and wet weather. You can determine the degree of wear of the rim brake pads by using special marks (grooves).
Worn pads should be replaced promptly to avoid damage to the rim. Note that both cartridge and disposable pads are suitable for V-brakes. And here the rule applies. the more expensive, the more effective.
BIKE BRAKE PADS, WHAT ARE
Cycling safety, the efficiency of its braking system directly depends on the used brake pads. Consider what are the brake pads for a bicycle, their advantages and disadvantages.
Depending on the design and price range, the pads are divided into varieties. And first of all, for two main types of brakes: rim (V-brake) and disc.
PADS FOR DISC BRAKE SYSTEMS
On the market, brake pads for disc brakes are metallized (Sintered) and organic (Resin). And these types have both advantages and disadvantages.
Factors such as rider weight, weather and trail conditions, riding style, and rotor size can dictate the selection of a suitable pad composition.
Replacing disc brake pads:
To replace the brake pads, the first thing you need to do is remove the caliper itself (the car) from the mounting plate to which it is attached with two bolts. It should also be added, before we go further, that the hands must be clean, in no case in oil, etc. When engine oil gets on the brake disc, it becomes covered with an oily film, the pad seeps out with oil. As a result, the braking performance is significantly reduced and the brakes themselves can make an unpleasant noise when operating. Further, depending on the model of your caliper, you should perform a number of tasks to dismantle old pads and install new ones. It should be noted that in some calipers, such as Shimano, a corkscrew pin is used to fix the pads, after pulling out which the pads can be completely pulled out of the groove, while in other brake models, to change the pads, you need to unscrew part of the machine body before unscrewing lock nut. You should also know that if, when installing new pads, one pad is thicker, then it is placed on the side of the driving pad.
Adjustment and maintenance of disc brakes
Unlike classic rim brakes, disc brakes are somewhat more complicated and costly both in maintenance and repair, but just like the first ones, you can service them yourself at home. We have already considered the design and principles of operation of such systems. therefore, we will not waste time reviewing their design and get started right away. The tool you may need to work with the disc brake is a set of hex keys (1 to 6). A very handy portable kit can be purchased on our website. Just as in the case of rim brakes, sometimes for a good robotic brake, it only needs to be adjusted, but sometimes (in disc brakes, this happens less often) it is time to replace the brake pads.
Customization. Despite the visual complexity of the design, disc brake setup is fairly straightforward.
First, make sure that the caliper is installed correctly, namely, the brake pads are parallel, that is, they evenly adhere to the entire plane on the disc brake. To set the caliper in the correct plane, you must first release the fixing cable bolt suitable for the brake machine (so that it moves freely), and then the fixing bolts. By clamping the brake with a lever on the caliper and slightly advancing the wheel, the pads will firmly adhere to the brake disc. After making sure that this is the case, tighten the bolts securing the caliper to the bike body.
Our next step is to set the gaps between the pads and the rotor. We set the right block by rotating from the side of the wheel in such a way that during the rotation of the wheel it does not touch the rotor, but at the same time the gap between the rotor and the block was as small as possible (after setting, some caliper models have a locking bolt. Be sure to tighten) The left pad is exposed by pressing the brake lever on the caliper. Having found the desired position, we clamp the supply cable on the caliper. This completes the disc brake adjustment.
Disc brake installation features
The most common brake system on a modern bicycle is disc brakes. Unlike classic rims, they have their own configuration features. A disc is installed on the wheel in the area of the hub, pressed on both sides by pads. The time it takes for a sharp braking directly depends on the strength and speed of this clamping.
Most often, this type of braking system can be found on mountain bikes. The fact is that disc brakes are very effective in difficult rough terrain and high speeds.
In order to install disc brakes on a bicycle, you can go to any bike workshop, or carry out this process yourself.
In what cases it may be necessary to replace the disc brake:
- A certain element has flown in your brake system that needs to be replaced
- The entire braking system has fallen into disrepair, and you replace it with a new one
- Your bike had a different brake system, but you decided to replace it with a disc
This type of braking system includes:
- A pen
- Brake line
Modern disc brakes are divided into several subtypes:
what the braking system consists of
Before installing such a braking system on your bike, be clear about your future ride, as it directly affects the size and configuration of the brakes. If you prefer to ride on steep mountainous terrain, it is better to opt for large-diameter brakes; small structures are quite suitable for short walks in the metropolis.
In order to install a disc brake, you will definitely need the following tools:
- Allen key
- Thread lock
Following a simple algorithm of actions, you can easily install a disc brake system on your bike.
- Find a suitable workplace. Ideally, this could be a garage, but if there is none, you can sit on the balcony.
- Remove all attachments from the bike, including the wheel.
- With the brake levers locked in place, install the caliper. But, before doing this, you need to check for the presence of a thread lock on the bolts. If it is missing, you will have to apply the fixer yourself.
- Secure the caliper with a hexagon and the brake hose with clamps.
- Reinstall the wheel and all removable parts of the bike.
- Spin the pedals and try hard braking to test how functional the system is.
If you’ve never ridden a bicycle with disc brakes, it can take some getting used to. Do not go long distances at once, but practice driving in a place that is familiar to you. You will quickly adapt to new driving conditions and experience the enormous benefits of a disc braking system.