operating errors of hydraulic disc brakes
In order to safely roll through life, you need a good reaction, observation and, most importantly, reference brakes.
We have already told you what you need to know before choosing hydraulic disc brakes, which are considered the most in demand in terms of quality. And when you buy disc hydraulics for your iron horse, you should know what mistakes you should not make when using them (by the way, some of these principles can be applied to mechanical disc brakes).
So, a number of rules, following which, your rotors will last you longer and will require a little attention.
Never touch the braking surface of the rotor.
- Firstly, after intensive braking, the rotor is very hot and you will definitely burn yourself.
- Secondly, (KEEP ATTENTION!), Grease from the fingers can stain the rotor, which is fraught with a decrease in braking efficiency and the appearance of extraneous sounds during braking.
If oil accidentally gets on the rotor or pads, this will lead to much more serious problems. If you notice that oil has dripped onto the rotor, for example, when inaccurately lubricating the chain with lubricant in aerosols or when pumping the hydraulic line), you need to carefully remove the wheel and wipe the rotor with a degreaser. At the same time, it is important that the oil does not get on the pads, because they have a spongy structure and willingly absorb oil and you cannot get rid of it with any degreaser. If oil does get on the pads, the brake will brake very badly, while making such sounds in which the pedestrians in front of whom you brake will rush into the loose without looking back. In this case, it is best to replace the pads.
True, there are a couple of “collective farm” methods that have a low percentage of success. If a little oil gets in, then you can try to grind the brake surface of the pads by removing a small layer of contaminated material, but a simpler and more effective method is to heat the pads. When exposed to high temperatures, oil trapped in the block will begin to burn out in the form of smoke or even a small flame. But here it is important not to overdo it. if the pads are heated too much, the braking surface can crumble.
Do not press the brake lever with the wheel removed. If you do this with hydraulic brakes without a rotor or spacer between the pads, the pistons will push until the pads close together and no longer go back on their own just enough to lock the rotor into place. Fortunately, this is easy to avoid: insert a special spacer instead of the rotor when removing the wheel. This spacer always comes with the brakes, but if you do not have one, then you can do with improvised means: use instead of the spacer, for example, an unnecessary plastic card or cardboard bent in half. But if your pads still “come together”, you can remove the pads and try to gently dilute them with a flat screwdriver. If you spread them more than was necessary, then put the pads back in place, put the wheel and push the brake lever a little. the pads will take their place.
Remember to check the thickness of the brake pads. Although disc brakes have a long service life, the pads and rotor will still gradually wear out. If you see that the brake pad material is thinner than 2.5 mm, then it is time to change the pads. The rotor has outlived its life when its thickness becomes less than 1.5 mm.
Use the right tools and supplies if you intend to service your brakes yourself. Never confuse brake fluids. If your brakes use mineral oil, then in no case should you pump them with a pillbox and vice versa (which brake fluid is used in your brakes is usually indicated on the brake lever. see the picture).
If you make this mistake, you will fatally ruin your brakes. Do not line bent rotors with bare hands and you know why (remember the point). There is a special tool for this. Observe the correct tightening torques for the fasteners recommended by the manufacturer. To do this, you need a torque wrench.
Want to learn how to properly service your brakes? Consult our bike mechanics at:
- m. Beresteyskaya, st. Degtyarevskaya, 51V 38-050-388-29-11
- m. Poznyaki, st. Prince Zaton, 11 38-050-388-29-12
Or take the first course “Basics of Bicycle Mechanics” in our School of Bicycle Mechanics and service the braking system of your bike yourself.
Bicycle brake rotor
The brake disc (rotor) can be of the following sizes: 140, 160, 180, 185, 203, 220 mm. Which one to choose? This is the question most cyclists face, consider how and what the rotor size affects.
In a nutshell, the larger the rotor, the more effective the brake, this is due to the fact that the larger the rotor, the larger the lever arm of the braking force. Everything is easy and simple. In most cases, 160 and 180 mm rotor is used for non-extreme riding. For more extreme or powerful braking use 203 and 220 mm rotor.
Disc brake types:
- mechanical (the basic principle of operation of the brakes using a cable, which is placed in the shirt);
- hydraulic (the basic principle of the brakes is with the help of brake fluid or mineral oil, which is in the hydraulic line).
Pads are also important, so they can be metal filled or organic. Pads with metal filling are made with a filler of metal filings, so they are more wear-resistant and rub in for a long time, and organic ones are softer, therefore they give smoother braking, quickly rub in and provide better braking.
V-brakes are usually found on budget bike models. Not all frames can be fitted with these brakes due to the lack of pivots for installing this type of brake. It is advisable to use rim brakes when cycling calmly. They are not whimsical to maintain, quite lightweight and cheap in comparison with disc brakes.
Mechanical disc brakes have good braking performance, so it is advisable to use them if you are riding at a more aggressive pace and with limited funds. expensive than rim brakes, but cheaper than hydraulic brakes. The Avid BB-5 and BB-7 disc brakes have been particularly popular in recent years. Hydraulic disc brakes are needed only when high braking power is important, which is why it is used in extreme conditions (for example, downhill. downhill descents). They need periodic oil changes, the hydraulic lines require careful handling, as they can be damaged if dropped, which will entail additional costs.
When buying their hydraulic type, it is necessary to clarify in advance where you can purchase spare parts for it, so that in the event of a failure of a part, you do not have to change the entire set.
Hydraulics should be chosen only by those who drive over rough terrain and love extreme sports. Otherwise, don’t waste your money. Buy mechanical or hybrids that are optimal for cycling and city riding. Their reliability and ease of use will not make you regret your choice.
When buying disc brakes, pay attention to the size of the rotor, which directly affects the braking efficiency. The larger its diameter, the better the response.
The smoothness of the brake depends on the brake pads. Depending on the content, they are organic and mechanical. The latter type contains metal filings. Because of this, they are more wear-resistant, but take a long time to fit for better performance. Their organic counterparts provide gentle braking and rub in almost immediately due to their softness.
If you need to choose powerful brakes, then you should pay attention to the markings. The presence of the abbreviations AM, FR, Trail and DH in it means that you can rely on them. They will provide powerful braking in any situation.
From the above, it follows that mechanical disc brakes are the “golden mean” and are the best choice for any cyclist.
Advantages and Disadvantages of Disc Brakes.
Here are the obvious differences between disc and rim counterparts. Let’s highlight their advantages over the last type of brakes and point out the disadvantages.
The positive characteristics include:
- are durable;
- you can ride with them in any weather, because they are not clogged with snow and mud;
- provide a high coefficient of friction between the metal disc and the abrasive in comparison with the mechanical indicator (pad and aluminum rim);
- works faster and withstands downhill slopes;
- the rim and wheels practically do not wear out;
- his discs are not afraid of strong heating and sudden braking;
- one adjustment is enough for the entire period of operation;
- if the bike is damaged, it will not affect their work.
There are some negative points, these include:
- installation and maintenance will require special tools;
- some models differ in perceptible weight, and because of it there is a load on the hub and spokes of the bicycle;
- high price;
- difficulties may arise when replacing brake pads;
- often get in the way when installing a bike rack.
Today, hydraulics are considered the best type of disc brakes. The above positive aspects mostly concerned her. and more riders, taking care of their safety and comfort, install this system on their bikes.
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.
Are Your Brakes Dangerously Weak? Check your bicycle brakes for these 3 Symptoms!
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.
Advantages and disadvantages of hydraulics
Dosing accuracy and the speed of response of the mechanism to pressing the handle are two main qualities that have led to the widespread use of hydraulic brakes. These are far from the only advantages, but they are the ones that made the downhill athletes turn to hydraulics.
The excellent endurance of the hydraulic brakes also played a role in the migration of hydraulics to the bike. As well as the accuracy of actuation, this was a very important quality for downhill.
The reliability of the system has been proven over the years of its use in automobiles. With proper care, hydraulic brakes on bicycles are many times more reliable than mechanics. The heightened sense of the strength of the dosage allows you to manipulate the brakes with jewelry precision. In extreme sports, this is a must.
The disadvantages of hydraulic brakes include the following: The cost of a hydraulic system is much higher than a mechanical one, therefore a bicycle with hydraulic brakes will be more expensive. Complexity of service. The hydraulic system is a rather complex and technologically advanced unit that requires maintenance skills and a clear knowledge of the design and its features. Not every biker is able to independently sort out the system and carry out its high-quality repair. Also, field repairs in the absence of experience can be difficult. Brake pipes and hoses require careful handling. They are quite vulnerable and the quality of the entire system depends on their condition. Also, brakes can be picky about the quality of the brake fluid or oil, so you should make a deliberate choice when pumping.
Most often, hydraulic brakes are used in tandem with disc brakes. Literally a few words should be said about them.
Types of hydraulic disc brakes
The main difference between a disc brake and a conventional rim brake is that braking occurs by clamping the brake disc, rigidly fixed to the hub, with brake pads, which are fixed at the rear on the frame and at the front on the fork stays.
The design of the main brake cylinder can be different, and depending on this, hydraulic brakes are divided into the following types:
- Single piston;
- Twin-piston with opposed pistons;
- Two-piston with floating pistons;
Mostly used two-piston with opposed pistons. There are also single-piston ones, but due to shortcomings, they were almost completely replaced by two-piston ones. Complex multi-piston systems are used mainly for downhill, where power plays a decisive role, rather than simplicity of design.
Due to the type of fluid used in hydraulic systems, brakes can operate on brake fluids and oil. Each of them has its own advantages and disadvantages, but there is no unequivocal opinion on this matter. The caliper can be monolithic, which makes the structure stiffer and lighter, and composite. cheaper in price, but more difficult to maintain.
The hydraulic disc brake is very reliable, but it is not easy to repair and adjust in the field. True, to bring the hydraulic brake to a coma state, you need to try very hard.
There are some problems associated with the fact that disc hydraulics have a very small gap between the pads and in the presence of heavy dirt, the pads are subject to increased wear. But mechanics have no advantages in this case, since worn-out pads cannot be adjusted on the fly, while hydraulics are automatically supplied in the course of wear.
They are more expensive than rim ones, slightly increase the load on the hub during braking, although this is a controversial issue. We will not delve into the details of the drive in detail, since this is a separate topic for conversation, but for now, let’s start considering what the manufacturers have prepared for those who want to put hydraulic brakes on the bike.
Principle of operation
The brake line is filled with a special oil or brake fluid under low pressure. When the brake lever is depressed, the bicycle brake cylinder displaces fluid from the hydraulic system and it applies pressure to the slave cylinder, which is mounted on the fork or bike frame. In turn, the slave cylinder drives the piston and brake pads, which block the wheel by means of the brake disc. Very simple. Here is a diagram for clarity.
When working with hydraulic brakes, it is worth considering that brake fluid is very toxic and can cause severe poisoning. It also has a detrimental effect on paintwork and plastic parts.
Features of Hydraulic Bicycle Brakes
The vector of action of the brakes, both mechanical and hydraulic, is one. stop. a car. But there are a lot of nuances and questions to both one and the other brake drive circuit. Today we will try to wash the bones with hydraulic brakes.
Their main difference from mechanics is that a hydraulic line is used to drive the brake pads, and not cables. The hydraulics connect the brake levers directly to the brake mechanism. In the role of which can be both disc hydraulic brakes and conventional rim.
Review of the best
Out of a million types of braking systems, hydraulics are increasingly found on mid to very mid-range bikes. As their popularity grows, the price falls accordingly. Therefore, it makes sense to consider converting your bike to a hydraulic braking system. There are many examples, but we will give only two. For contrast.
Shimano unveiled a new collection earlier this year, revamping the Deore line. Nice grips, stable operation of the main brake cylinder gives real pleasure from precise actuation and obedience of the entire system as a whole. A slight rattling of the handle itself darkens the picture a little.
The new range offers a choice of splined or bolted rotor mounting. Shimano Deore comes with two types of pads. rubberized and metallized. The former wear out very quickly. The hydraulics in general are of excellent quality and their 50 is definitely worth.
CLIM 8 CLARK`S. The advantage of these brakes is that for the price of a single cylinder you get a full multi-cylinder hydraulic brake. But miracles do not happen, and you have to pay for everything. The design of the handles is a little alarming, but this is not for everybody. But the hydraulic hoses are reinforced with Kevlar and metal.
The caliper has an interesting six-cylinder design that promises to be reliable. The disadvantages of this system are the slightly increased weight. In installation, they are also not as easy as they seem. during installation, they require careful adjustment of the pads to the discs.
Bleeding the brake hydraulic system
Reasons why you should do brake bleeding:
- when you press the brake lever, it goes out to the grip itself, i.e. has too long a stroke, but at the same time the pads do not move, or do not reach the brake disc;
- the brake lever falls through when pressed or has too little movement;
- when the handle is pressed sharply, after the brake is applied, the handle continues to fall smoothly.
All clear. The reason for the failure of the brake system was the air that got inside. The first step is to find the place where the system grabbed the air. This can be damaged hydraulic fittings, boiling of the liquid due to overheating, a weakened pumping union on the cylinder. After checking the entire system for fluid leaks, you can start pumping.
We always pump the hydraulics on a flat and horizontal surface. The pads should be spread apart so that they do not reach the disc. Next, we unscrew the master cylinder and fix it strictly horizontally. Each system has its own characteristics of pumping, so it is better to do it according to the instructions. The pumping fluid must correspond to the brand indicated in the passport.
Now you should put the cambric on the bleed bolt and immerse it in a container to collect the remaining fluid. We unscrew the cover of the expansion tank, fill in the liquid to the maximum level. Several times smoothly and slowly press the brake lever. Press until it becomes tight. Now holding the handle, unscrew the bleed bolt with a cambric, without releasing the handle. Add liquid to the expansion tank. We carry out the procedure until the handle becomes stiff. We twist the expansion tank and remove the tool. Done, brakes pumped.
So the rumors about the difficulty in servicing hydraulic brakes are greatly exaggerated. Along with some disadvantages, such a system has more advantages. But in principle, the principle of operation of this or that mechanism is not so important to a real biker as the very fact of free movement in space.
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 nuance should be taken into account. if the hydraulic system is closed, then you will have to adjust the pads manually. 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.
After carrying out the work, be sure to check the operation of the brake system in action. ride your bike for a few meters and try to brake. If the cable was overtightened, 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.
Checking the readiness of the system for adjustment
- The adapter to which the caliper is attached is well secured to the frame or fork (bolts are tight).
- The already tested rotor is securely fixed with screws on the hub.
- The wheel is mounted on the bike, the eccentric / nuts are tightened.
- The lamb for adjusting the cable tension is unscrewed no more than 1.5 turns (located next to the handle or caliper).
- The cable is fixed on the movable arm of the machine.
How to adjust disc mechanical brakes on a mountain bike
Mechanics are gradually becoming history. Now it can still be seen in the budget line of Russian Stels, Forward and Stern. Considering the price, there is no need to talk about the belonging of brake system parts to such global brands as Shimano and Sram. Usually this is some kind of noname kit that has a minimum of settings.
Another nail in the list of disadvantages of mechanical disc brakes is that they need to be adjusted more often. This is because one of the pads is motionless. As it is erased, the distance between it and the disc automatically increases. Meanwhile, fluctuations in the values of this gap should be insignificant, otherwise the friction linings will wear unevenly, the quality of deceleration suffers.
How to Adjust Disc Brakes on a Bicycle: Techniques for Hydraulics and Mechanics
Normally, the disc brake stops the wheel as quickly as possible, allowing the force to be dosed on the verge of blocking the rotor. Deviations appear after replacing the cable, pads and overhaul. However, the settings are violated during long-term use, as well as after removing the wheel, for example, to seal the bicycle camera at home. How to avoid the famous shuffling of the rotor, how to eliminate the braking, and, in the end, how to restore the factory braking character. these and other questions are answered by the editorial staff of Autobann magazine.
How to make the brakes brake well
Use good quality pads and center the caliper in time with the rotor so that the disc bends as little as possible.
How to adjust everything yourself
It may be necessary to adjust the hydraulic brakes if you notice extraneous sounds while driving. creaking or rustling. A simple test will help to make sure that the adjustment is necessary: lift the wheel of the bicycle and spin it. If the pads touch the brake disc, the wheel will quickly stop spinning.
The relative position of the pads and the rotor must be very accurate, because this affects the performance of the brake. To check the position of the disc in the typewriter and the position of the pads, place a white sheet under them and, if necessary, direct a bright light on it. against such a background it is easier to notice deviations.
Adjust the hydraulic brake as follows: 1. Loosen the caliper mounting bolts as much as possible so that it can move freely to the sides.
Squeeze the brake lever so that the pads are fully pressed against the rotor.
Check the position of the pad valves. they should be symmetrical, at the same distance from the rotor. Move the caliper slightly to the left or right if necessary.
Without releasing the brake lever, tighten the caliper mounting bolts.
Release the handle and check the brakes. Ideally, the pads should be at a minimum distance from the brake disc, but not touching it.
If you notice that one pad is located closer to the disc than the other, but the rotor itself is perfectly centered in the machine, do the following (preferably two people): press the disc against the more protruding pad and apply a little brake. Due to the fact that one valve works more than the other, they will align, and the problem will be eliminated.
The final touch is to set the position of the brake lever relative to the steering wheel. Sitting in the saddle, check if you feel comfortable using the brake lever and if you can quickly press it in an emergency. If the knob is too far for you, tighten the adjusting hex a little more. this will bring the knob closer, but at the same time the pads will move closer to the rotor. The main thing here is not to overdo it and not to make the stroke of the pads too small.
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 other rim brakes is done in the same way. The only difference will be that the bolts and screws that 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.
- You can learn more about repairing disc brakes on a bicycle from the article.
- Setting up and installing hydraulic brakes on a bicycle is done in a different way, you can learn more about this here.
- Learn all about vibrays, their configuration and installation.
Actions to check and adjust the brakes
Setting up disc brakes on a bicycle is different from setting up rim brakes because they use different pads and rotating parts. Therefore, we will consider these systems separately.
V-Brake. adjusting the brakes on a bicycle video
A small instruction on how to achieve this.
- We find the hex nut that fixes the pads, loosen it and set it as needed. To do this, press the brake, watch how the shoe touches the rim when pressed and, if necessary, move it (after releasing the brake). The block can move both up and down, and at the desired angle, so you have the opportunity to set it up as needed. The main thing is to understand the essence.
- We adjust the distance of the pads relative to the rim. The distance between the right shoe and the rim and between the left shoe and the rim must be the same. It should be 1-3mm depending on your bike. In this case, braking should occur even with a minimal push of the handle. That is, it should not be so that you have pressed the handle halfway, and the wheel does not stop yet, and only when fully pressed, braking occurs!
- And finally, it is imperative to check the action of the adjusted brakes in practice. To begin with, you can do this with one wheel raised and then the other. But then be sure to check in real conditions. (Sometimes the wheel slows down in the air, but get behind the wheel, press the handle and drive on!) Therefore, drive 5 meters, press the brake and check all the conditions mentioned above. If when you press the handle 50% (before the steering wheel) the brake is activated, congratulations! You did everything right!
Successful rides for rim brake owners!
- You can find out which brakes are the most popular in this article.
- How to adjust and disassemble the roller brake
- Disc brakes or rim brakes are better
Adjusting and adjusting disc brakes on a bicycle video
Adjusting disc brakes on a bicycle is done mainly by pulling the brake cable, but not only. Replacing pads on a bicycle is necessary when they are not yet completely erased and, as a rule, disc brake pads take longer to wear than rim pads. The hydraulic brakes are self-adjusting as the pads wear out. But in the case of a closed type hydraulic brake, it is also necessary to adjust them (usually special valves are provided for this).
Adjusting mechanical disc brakes on a bicycle is most often accompanied by a tension on the cable to provide reliable braking. The distance between the pad and the disc should be 0.2-0.4 mm. And the pads, as in the case of rim brakes, should be located at the same distance from the disc. Therefore, after you tighten the cable, check the position of the brake pads.
To adjust the position of the pads relative to the brake disc, special bolts are provided. By twisting them, you can see how your last moves. Set the desired distance from the pad to the disc. Make sure that when the wheel rotates, the pads do not catch the disc. After all, the gap of 0.3 mm is very small, and you need to be careful. And of course, check that the clearance you set is enough to brake the wheel.
Mountain Bike Maintenance: How to fix spongy disc brakes
Adjusting the disc brakes of a bicycle must always be accompanied by a test under real riding conditions. Drive on level ground for a few meters to determine if your brake is working reliably. Do not forget that if before that you hooked the steering wheel with the handle, now everything can change significantly. Be careful and careful! Braking too hard after tuning may come as a surprise!
Now you can go on a long and not only trip on your bike with pleasure.!
- It is more convenient to set up and adjust the brakes if you have a rack (holder) for repair and maintenance of the bike
Repair, adjustment and adjustment of brakes on a bicycle with your own hands
Timely brake adjustments can help keep you out of trouble
There are two types of brakes on modern bicycles. rim and disc. Which braking system is used on your bike will determine how you adjust the brakes on your bike. As a rule, the brake does not require frequent adjustment, but there are times when adjustment is simply necessary. After all, a reliable brake is the key to your safety.
often than not, adjusting the brakes on a bike means placing the brake pads at the correct distance from the rim or disc and symmetrically to each other. Also, it may be necessary to tighten the cable or adjust the brake lever.
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 turn 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.
Adjusting disc brakes on a bicycle is done 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. a matter of technology. By tightening the screw, you can immediately adjust the position.
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.
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 device as simple as two or two. What is the structure of this mechanical brake system? There are levers that are mounted on the steering wheel. There are tubes (it is correct to call them “shirts”), inside which an iron cable fidgets. Two clips and pads. Everything is nothing more. That is why there are only three positions on which it is worth adjusting the V-break.
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.
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 that it instantly transmits 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 firmly, the rider can fly out of the saddle in the truest sense of the word. 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 repaired by yourself. The slightest upset. and a trip to the workshop is assured. And again, repairs will cost a pretty penny. Parts of the system, such as tubes, are not very reliable. If this part bursts, the brake fluid will leak out. Therefore, you can only brake with your feet. Adjusting hydraulic brakes on a bicycle is tricky. If possible, it is better to entrust this to the master.
Mechanical disc 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 drive V-breaks all your life and then switch to disc brakes. After all, you will have to learn to configure this system again.
Adjusting the rear brakes on a bicycle
In theoretical terms, everything seems to be 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 rim brakes on a bicycle is a delicate thing. So you need 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 fray to holes. It is undesirable for the block to also go beyond the boundaries of the wheel. From this, it is quickly erased, but there is no desired effect (good inhibition). 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. After examining the situation, you can immediately see where something is wrong. Use this tool to loosen the washer. Then, while also 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.
Disc or rim brakes: which is better?
Most likely, no one will doubt that brakes are one of the most important parts of a bike. 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 an emergency on the road in a short period of time, 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 worthwhile to first figure out what kind of braking systems exist, as well as compare the advantages and disadvantages of one or another braking device.
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 almost impossible to use the brake. Also, in rainy weather, braking is uncertain, due to wet pads and wheel rim. 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 because 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 that 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 often warp, creating unnecessary friction on the rim, they quickly become dirty and are marked by 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 mounts. When you press the brake lever on the steering wheel, 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 that 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 approach of the 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 speed. These brakes are simple enough 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.
Types of bicycle brakes.
Every day, technology, as well as bicycle parts, are being improved. Therefore, the types of brakes that were used in the past may no longer be installed on modern bicycles. In this regard, we will only talk about two main types of brakes.
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 brake.
Are the brakes on your bike slowing down badly? Analysis of the problem.
Have the mechanical disc brakes stopped slowing down? Major breakdowns.
The advantage of mechanical disc brakes over rim brakes is that small eights on the wheel do not affect the operation of the brakes, everything is within reason, of course)). But this type of brakes also needs to be paid attention, tuning and adjustment.
- If the brakes are abruptly lost. check if the cable and brake shirts are in place, the cable may have broken, it needs to be replaced.
- The brakes began to squeak and squeak when braking. it is necessary to clean dust, grease, dirt from the brake pads and rotor, degrease the rotor. There is already an article about this problem in our blog.
- The brake lever is fully depressed, with good effort, but the brakes do not brake well. check the clearance on the pads, adjust. Clean the brake caliper, pads and rotor, it is highly advisable to degrease all elements.
- If the rotor is rubbing against the pads, check if they are in the caliper. The caliper itself could be displaced from the installation site, fix something that is not in place.
Stopped braking on the bike, what’s the problem?
Analysis of a problem that is directly related to the safety of the cyclist. good, tenacious brakes. Effective brakes on a bike will give you confidence while driving and the ability to stop in time in front of danger. Before reading, we recommend that you read our article on the types of bicycle brakes.
The article will briefly describe the possible causes of weak brakes on a bicycle, brief recommendations for elimination.
Major breakdowns of bicycle V-brakes (rim).
The pads are rubbed against the wheel rim, tire, or even come together and do not diverge to the sides of the rim.
- check the pads for wear, they may need to be replaced, how to check this can be read in this article.
- find a place to mash. something stuck between the frame or dirt, other foreign objects.
- fix the “eight” on the wheel, if the wheel is level, adjust the slope of the “ears” of the brakes in the desired direction.
- check the position of the pads, must be parallel to the braking surface, align.
- check if the wheel is correctly inserted into the axle of the fork or frame, check for damage to the cable and shirts, whether all elements of the brake system are in place
If rim brakes do not give you the efficiency you need, read our article on upgrading V-break brakes.
Does the hydraulics on the bike slow down? Faults in hydraulic brake systems.
The most efficient type of bicycle brake available today. hydraulic or “hydra” by the people. There are usually fewer problems with such brakes, but if they do arise, most likely you cannot do without a workshop and straight hands.
- If the brake lever has dropped sharply. first of all, check the tightness of the system, leakage, fracture, cut in the hydraulic line, torn out bolt, fitting on the caliper or handle. you need to replace the part that has broken down and bleed the brakes (get rid of air in the brake lines, calipers.
- By pushing the handle, the brakes react at the end of the handle travel. it is necessary to pump a sealed system into which air has entered, replace the waste fluid. Also pay attention to the wear of the pads, they may need to be replaced.
- The rotor is jammed between the pads. such a situation is possible in very hot weather, the bike was lying in the sun, the liquid in the system expanded from heating and the pads were reduced. Let the bike and brake system cool down, the problem should go away.
- When removing the wheel, the pads came together, it is impossible to insert the rotor between the pads. most likely the brake lever was pressed with the wheel removed. It is necessary to “spread” the pads with a knife, flat screwdriver, wedge them. Care must be taken in this process so as not to damage the pads.
- The hydraulics squeaks, whistles, makes a loud noise when braking. dust, dirt, grease, oil have got on the pads and rotor. you need to clean and degrease the parts. How to get rid of the oil on the pads in this article.
HOW TO FIX SPONGY OR WEAK HYDRAULIC BRAKES // SHIMANO
Keep your brakes clean and inspect and service regularly. this is the guarantee of their durability, good adhesion of the pads and your personal safety.
Troubleshooting disc brakes
Why are my brakes screeching?
This is most often due to pollution. Sometimes it’s a bad setting, sometimes. warning about the need for new pads, sometimes. this happens because the pads are polished, or of the wrong material, but most often it is dirt.
Keep all oils, degreasers and bike cleaners away from pads and discs to prevent squealing. And, of course, the brakes must be worn.
Why do I sometimes hear brake friction when not braking?
Disc brakes operate to very close tolerances, usually just a millimeter or less of space between the rotor and the pads. This leaves little room for error. If sometimes you hear brake friction, this is either a sign of a bent disc, or the brakes need service, or an external influence.
Friction can be caused by the flexibility of the hubs and frame (forks). Do you sometimes hear these sounds when you tilt your bike while cornering or sprinting? If so, that’s flexibility. First, check if your axles are tight. Also make sure the hubs don’t play. If all this does not solve the problem, make sure that the caliper is correctly positioned with even pad clearance on both sides of the rotor. If this does not correct the situation, then the problem may be simply in the flexible axis or the installation of dropouts.
Sometimes the pads rub because the pistons behind them stick. This can be due to accumulated dirt, and sometimes simply to prolonged use. Servicing the brakes (with reinstalling and cleaning the pistons) and bleeding them usually solves the problem.
Finally, there may be enough dirt, sand, or just water to make the discs shuffle or even howl. If you just drove through a puddle and the discs rub a little, do not worry about it. The very first press on the brake will most likely clear the dirt and restore silence.
A deformed rotor causes friction in the brake every time the wheel is rotated.
My brakes rub, but only at one point on the wheel. What to do?
The disc appears to be deformed. It is only about two millimeters thick, so it may well bend. Be careful not to lean your bike discs against anything and be doubly careful when transporting your bike in a car or case so as not to bend them.
If this happened immediately after a long descent, it may be due to overheating. Allow the rotor to cool down, and if it is still deformed, follow the advice below.
If the rotors are not critically bent, then they can be pulled out or bent into their original shape. This is usually done with the wheel mounted on the bike, using the brake pads as an indicator. Take a piece of clean paper towel to touch the surface of the disc, and gently press down with your thumb at the rubbing point to bend the disc backward. Take it easy! No effort required to bend the rotor back.
For greater accuracy, there is a special tool (in the ProVelo workshop). Alternatively, an adjustable wrench can be used, but make sure it is perfectly clean before using it.
My hydraulic brakes are rubbing constantly. What to do?
You just shot the wheel and now they rub like crazy? If so, see the section above on traveling with disks. It talks about how to put the brake pads (and pistons) back into the caliper to reinstall the system.
If this was not the case, your brake caliper probably needs to be aligned. Look through the caliper to see if the rotor is rubbing on only one side. Yes? Okay, then you need to loosen the two bolts holding the caliper in place. Most calipers can then be automatically aligned by pulling on the brake lever and pressing the pads against the disc. Then, while holding the lever, tighten both bolts. Sometimes it doesn’t help, but there are many other tricks to deal with it.
Align the caliper visually and tighten it gently (with a white sheet on the ground to improve visibility).
Another variant. use a business card between the rotor and the rubbing block. With the card in place, repeat the process above. Loosen the caliper bolts, press the lever and tighten the bolts while holding the lever. This may take several tries, but it usually solves the problem if the brakes do not want to slide into place automatically.
If you’ve just installed new pads and the clearance is minimal, try pushing the pistons back into the caliper bores (use a plastic tire raiser or the rounded back end of a small wrench). Sometimes there is too much fluid in your brake system (this happens if the brakes were quickly bled or the system was replenished with worn out gaskets. You need to bleed the system again or, carefully opening it, release some fluid (without letting air in!).
Several people have tried to adjust my brakes, but no matter what, the pads do not fit correctly on the braking surface of the rotor. What to do?
If the caliper alignment is correct and your rotor is straight, then it looks like the frame (fork) is to blame. Ask the frame manufacturer how to fix the problem, but they will most likely suggest a replacement (preferably at their expense, of course).
Sometimes paint or simply poor manufacturing tolerances can cause caliper alignment problems. Park Tool offers a tool called DT-5.2 Disc Tab Facing. This tool removes material until the brake caliper mounting surface is parallel to the axis. This is an extremely expensive tool, so look for the workshop that has it (unfortunately, there are not many of them, but the ProVelo workshop does).
Park Tool Disc Tab Facing Tool (DT-5.2) is designed to align brake caliper mountings of all standards. A useful thing that is in the ProVelo workshop.
My disc brakes are running out of power. What can be done?
This could be due to several reasons, but most likely it is one of the problems below.
First, it is most likely that the braking surface is dirty. Even a little greasy sweat from your fingers can reduce the effectiveness of disc brakes. Cleaning the system can help, but if it is heavily soiled, new pads and a thorough rotor cleaning are needed.
On extremely long downhill runs, lining may occur. This can be determined by their glassy surface. Remove the pads and sand them with sandpaper. this should help.
Air in the system can also be to blame, which interferes with efficient transmission of power from the lever to the caliper. Bleeding the brakes will solve this problem (see the section on bleeding the brakes above).
Finally, it may be that your brake rotors are not large enough for your riding style or body weight, especially if your bike is now equipped with 140mm discs. Find out if larger rotors will fit on your bike for more leverage.
What to do if the hydraulic brake lever falls very close to the handlebars?
It looks like there is not enough fluid in the system. Check to see if bleeding is required by following the guidelines in How Do I Know When My Brakes Need Bleeding? (section above).
If this is not the case, then it is known as leverage failure. You have several options for solving.
Pumping the brake pads closer to the rotor will provide less lever movement. To do this, remove the wheel (and rotor) and carefully press the lever until you see the movement of the shoes. Reinstall the wheel and check the feel of the lever. Repeat this procedure until the lever moves properly. Keep in mind that this will make it difficult to fit without friction and will only work as long as the pads are not worn out.
Some brakes also have a lever travel adjustment. If you have one, then there is an adjusting screw that you can use to reduce its travel.
Why do my brakes lose power during extended braking??
Sometimes this is a sign that the brake fluid is overheating and starting to boil. When this happens, which was previously incompressible, the fluid becomes a compressible gas and the braking quickly loses power. In this case, it is highly recommended to upgrade to a larger rotor size or fit heat dissipating pads and discs (e.g. Ice Tech from Shimano).
It is also possible that there is air in your system (see the section above on bleeding the brakes).
Make sure the brakes do not overheat.
What to do if the brakes suddenly lose power?
The first thing to do is try to pump up the brake. Just press the lever quickly for some time. If it is air causing sudden brake problems, then pumping the lever will likely move the bubble from the hose to the upper reservoir.
If this does not work, then most likely you will only have a service brake on one wheel. Use it carefully to get to the house, and then contact a mechanic for service (repair). Although very rare, a faulty component could be a possible culprit for a system failure.