Hydraulic brakes for bike
Which brakes to choose?
Rim or disc? Or maybe the foot brake is enough? Every cyclist asked himself such a question, first when choosing a bike, then when replacing or improving it. In principle, this question can be answered rather briefly.
The foot brake is great for leisurely city rides and parks where simplicity is most important and power is not required at such low speeds. Also, this type of brakes is installed on most children’s bicycles, because children have more leg strength than small fingers on their hands.
Rim brakes have come a long way in design redesign. It all started with cantilever brakes, but as the width of the tires increased, the shape of the rim brakes also needed to be changed. For a while, U-brakes were installed, but in the end they came to V-brakes. Now these brakes are mainly installed on budget mountain bikes and hybrids. “Vibrakes” are the easiest to set up and maintain, because the whole mechanism is quite simple. A steel cable runs from the brake handle to two levers on which the brake pads are attached, which in turn clamp the wheel rim together. Rim brakes are still used on road bikes, including most professional road bikes. These high-level brakes have low weight and good performance on narrow wheels, although disc brakes have recently been installed on road bikes.
Disc brakes have long been used in cars and motorcycles, but bicycles were not introduced until the late 90s of the last century. At the same time, initially they were only hydraulic and were installed on the most expensive professional bicycles. It was immediately clear that disc brakes are the most effective and require the least amount of force from the rider. This is especially noticeable in bad weather conditions. The main disadvantage of this type of brake has always been weight. Indeed, in addition to the handle and the brake mechanism, a brake disc is also required. a rotor. Some manufacturers, such as Shimano, make Centerlock rotors, but the majority of the rotors are six bolted to the hub.
It is worth noting the difference between disc mechanics and hydraulics. The mechanical system is powered by a steel cable with its pros and cons. Tourists prefer mechanical brakes just because of their reliability, especially on a long journey, replacing the cable is much easier than bleeding the hydraulic system.
However, mechanical brakes require more force to brake well, which is why hydraulics are commonly used in racing. Hydraulic disc brakes on the bike allow you to spend less force on braking, as well as clearly modulate braking on difficult terrain.
Positive and negative sides
Hydraulic disc brakes have several distinct advantages:
- Speed of response;
- Accuracy of work.
Such systems allow you to easily stop transport at the right time or on a difficult section of the road. The main thing is that for effective work they need to be pumped and configured on time. Modern companies offer a large selection, which makes it possible to purchase a ready-made kit. The quality of the devices is at a high level, you can put the equipment on the bike yourself.
By the way, we recommend:
Bicycle brakes of this type also have negative aspects. For many riders, the cost of disc brakes is a deciding factor. It is quite high and the repair of transport can significantly hit the. In addition, the device of braking systems has its own difficulties and not every owner will be able to properly set up the work. In this case, you will have to seek help from professionals, which, again, will lead to certain financial expenses.
Running in new hydraulic disc brakes
Beginner cyclists who are not versed in all the intricacies of a bicycle and caring for it, probably faced with questions about the operation of the brake system. All new disc brakes, brakes after overhaul, or partial replacement of components need a break-in period. It doesn’t matter if they are mechanical or hydraulic.
During the break-in period, the efficiency of the brakes is reduced, therefore, it is not advisable to jump from place to place and use the brakes to the full extent. Particular attention should be paid to new brakes when both the brake disc and the pads are not rolled in at the same time. Do not forget about running-in when replacing brake pads. in this case, the running-in duration is reduced.
During the break-in period, 2 important things happen. First, the smooth surface of the new brake pads must become rough. Second, the material of the brake pads must get into the surface of the brake disc. Thanks to running-in, the work of the brakes is improved. braking becomes smoother, the efficiency of the entire system increases, vibration and extraneous sounds disappear.
When running in brakes, you can do a set of measures:
- Make 3-4 stops a little harder than normal braking. This will heat up the rotors so that no thermal shock occurs during running in.
- Perform 8-10 hard brakes without stopping completely, for example from 35 km / h to 5 km / h.
During the braking process, you may feel that the brakes have become “wadded”. this is the norm, because they are very hot. After braking, ride for 5-10 minutes so that the rotors can cool off from the incoming air flow.
Mineral oil or pillbox?
Hydraulic disc brakes use a special brake fluid to transfer power from the brake lever to the brake pistons of the caliper. In the process of evolution of bicycle brake systems, manufacturers have come to two standards for “brake”. DOT and mineral oil.
- DOT (US Department of Transportation). has become the generic name for working brake fluid in vehicles (not just bicycles). The key feature of DOT is the high boiling point of the liquid. At the same time, the boiling point decreases as the bunker starts to absorb water, so ideally change the bunker every 12-18 months.
- Mineral oil. made from petroleum and is a mixture of hydrocarbons separated from gasoline. It is used in various industries (including cosmetology), including used as a brake fluid. Fluid compression levels and boiling point are roughly similar to DOT.
All other things being equal, the boiling point of mineral oil and bunker is approximately the same, but “mineral water” has one important nuance. it does not absorb moisture, but accumulates it in the hydraulic system. If the accumulated water in the bunker reduces the efficiency of the brakes, then in the mineral water at a high temperature of the brakes, the water evaporates and leads to the failure of the system. Similarly, brakes on “mineral water” are not recommended to be used in the cold season, since the water accumulated in the system expands during freezing and the rubber bands of the pistons in the caliper or brake lever can simply squeeze out. Having accelerated and started to brake, you can find that there are no brakes, therefore, when using the bike all year round, it is recommended to use the brakes on the bunker or change to mechanical analogs.
Various companies, for example Shimano, offer a huge selection of disc brakes. They all have a certain quality, popularity and value. It is worth noting the Shimano brand, at least for the fact that their products are of excellent quality, and they rarely need repairs, the pads do an excellent job with their functions. Shimano’s latest series of system models have good clamping, but require careful selection. The set of this brand is quite acceptable and meets the criterion “price-quality”.
The quality of CLIM 8 CLARK`S hydraulic brakes is also at a high level, but during installation it is necessary to carefully match the pads to the discs. Unlike Shimano, this brand of braking systems has an interesting handle design, but this is not for everybody, the main thing is convenience.
The braking device can be selected in any price category. The quality of the braking systems will be at the appropriate level, it is just that repairs will be made less often for models that have proven themselves from a good side.
The text was prepared by Roman Borisov. Published: May 13, 2020. Sources: bb30.ru, velodrive.ru, yvelo.ru. Headings: Selection, Repair and maintenance.
- a bike
- disc brakes
- road bike
How to adjust the hydraulic brakes on a bicycle. Adjusting and adjusting hydraulic brakes on a bicycle
The principle of operation of hydraulic brakes on a bicycle is to transfer pressure through the hydraulic line from the brake master cylinder to the brake cylinder in the caliper, which in turn moves the pads. The brake fluid is not compressed, therefore such a system is more reliable and efficient than a mechanical one.
On the other hand, the hydraulic lines and the entire braking system require careful attention and constant maintenance, and therefore repairing and adjusting hydraulic brakes often seems to be a difficult task.
How to adjust everything yourself
Adjusting the hydraulic brakes may be necessary if you notice extraneous sounds while driving. squeaking or rustling. A simple test will help to make sure that the adjustment is necessary: lift the bicycle wheel 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 brake performance. 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 make the stroke of the pads too small.
Video demonstrating the entire adjustment process:
Replacing brake pads
Poor operation of hydraulic disc brakes can be due to the following reasons:
- damage or contamination of the hydraulic line or ingress of air into it;
- complete abrasion of the brake pads;
- dirty pads or disc.
In the first case, replacement of the hydraulic line or bleeding of the hydraulic brake is required, with the second and third cases it is easier to understand.
First, take a close look at the brake pads. All manufacturers prescribe their minimum thickness, at which the braking performance does not decrease. By the way, uneven wear of the left and right pads indicates that the rotor is not centered relative to the caliper.
As the pads wear out, the valves move closer to the rotor, so before installing new pads, you should slightly push them apart and re-adjust their position. The entire replacement procedure consists of the following sequence of steps: 1. Place the bike on a repair stand and remove the wheel.
Remove the retaining ring and unscrew the fixing bolt.
Pull out the old pads away from the hub axle. Remember the location of the return spring between the pads. it releases them after the end of braking.
Thoroughly clean the valve surfaces and the inside of the caliper. Use a lint-free technical cloth and a mild cleaner such as isopropyl alcohol.
Using a plastic lever, such as a tube changer, press both valves into the caliper. To install the valve correctly, you need to press on its center, not on the edge.
Install a return spring between the new pads and insert them into the machine.
Tighten the fixing bolt and install the retaining ring.
Clean the brake disc and replace the wheel. Check the correct position of the rotor, pads and the functionality of the entire system.
it should be said that all work should be done with clean hands. Also, to keep the brakes less dirty, you should close them when lubricating the chain. With a comprehensive bicycle service, the brake system is repaired last.
How to Adjust Shimano Hydraulic Disc Brake Levers in 5 Steps
To ride faster, you will most likely need a properly tuned and adjusted hydraulic disc. Plus, you can confidently maneuver over inconspicuous terrain and turns at incredible speeds knowing you have a brake that’s working and helping you to stop quickly. It is therefore very important to learn how to adjust the Shimano hydraulic disc brake levers.
Unlike cable brakes, hydraulic disc brakes require minimal effort and maintenance. Typically, hydraulic brakes act by applying pressure to the fluid and moving towards the caliper, which is pressed against the brake disc. With that said, we present a detailed guide to adjusting hydraulic disc brake levers.
How to Adjust Shimano Hydraulic Disc Brake Levers in 5 Steps
There are five steps to adjusting the hydraulic disc brake levers, including:
- The Shimano hydraulic disc brake lever is operated by a hand lever, also known as the master piston. The piston pushes the brake fluid through sealed brake pipes to slave pistons that are located at the caliper.
- When inspecting the hydraulic system, do not turn the bike upside down to prevent air from entering the brake lines.
- The Shimano hydraulic disc brake lever comes with two different caliper attachment systems. In addition, the caliper body can be bolted directly to the fork or frame rotor mount.
- However, in some cases, the caliper body can be bolted to the bracket while the bracket is bolted to the fork or frame. It is recommended to use thin washers when adjusting the caliper body, which attaches directly to the supports.
- When adjusting the caliper body, place a flat washer between the forks or frame support. Then install the washers and secure them with the retaining bolt. Once you’re done, assess the alignment of the rotor with the pad and you can add or reduce washers if needed.
2. How to make adjustments
Caliper alignment with the rotor is very important for brake performance. The following is the correct Shimano hydraulic adjustment;
- Always completely lose the mounting bolt for the calipers installed on the brackets. Once this is done, the caliper will move to the side.
- To maintain pressure and also to fix the pads on the rotor, the brake lever must be lowered. This will move the caliper and align the rotor and pads.
- Be sure to check the brake caliper and piston. By pushing the piston to the right and left, you will be able to center the piston.
- To maintain the pressure on the rotor, it is recommended to tighten the caliper with the bolts.
- After releasing the lever, check the initial pad alignment. The pad should preferably clean the rotor without any friction. However, there are a few cases where high friction can occur, but this should not affect performance. When your wheel slows down while cornering, you should consider loosening the mounting bolt on the caliper to adjust and reposition the pads and caliper.
- When you completely lose a mounting bolt, you can fine tune the pad alignment and tighten the other bolt. This allows you to push the caliper while turning the locking bolt.
Removing and replacing brake pads
When replacing or removing a Shimano brake pad, check if the pads are worn unevenly; this will indicate the state of alignment of the caliper with the rotor. Following is the procedure for removing and replacing a Shimano brake pad;
- Always place the bike on a stand and remove the wheels.
- Turn the lever on the handlebar so the top of the tank is parallel to the ground.
- Wipe down the lever as well as the reservoir lid. Remove the reservoir cap to flush out excess fluid in the reservoir.
- Remove the pad mounting bolt.
- Remove the pads by pushing them off the hub axle.
- Clean the piston area with a mild solvent and a clean rag.
- Insert the piston into the caliper body using a plastic lever similar to the tire lever Always push closer to the center piston, not the edge piston.
- After cleaning, slide the piston back into the caliper body.
- Install the caliper and evaluate the alignment between pad and bolt hole.
- Connect the pillow and secure it with the bolt.
- After installing the pad, screw the reservoir cover back in place.
- Replace the wheels and check them by pressing down firmly on the lever. If your lever feels soft, bleeding is required. However, if the pads are not aligned, you will have to reset them.
Replacing and bleeding brake fluid
Bleeding the calipers and lines is called bleeding the hydraulic system. Shimano hydraulic disc brake levers run on mineral oil. However, you should not use an automotive D.O.T. brake fluid in the Shimano brake system. Below is the procedure for bleeding and replacing brake fluid in a Shimano brake system;
- Place the bike on a repair rack and remove the wheels.
- To avoid contamination of the brake fluid, remove the brake pads.
- Install brake pads instead of pads. You might consider using a Shimano Y8CL18000 brake unit
- Then turn the bike so that the tube slopes upward from the brake caliper to the reservoir. Also, turn the lever on the handlebars until the top of the tank is parallel to the ground.
- Attach the drain tube to the end of the bleed nipple in the caliper You can use a plastic bag to collect excess fluid at the end of the tube.
- Remove any dirt from the arm by wiping the reservoir around the reservoir. Also, unscrew the screws on the reservoir lid.
- Remove the reservoir bottle and cap and fill to the top.
- Loosen the bleed nipple on the caliper body.
- The liquid level may drop when bubbles appear in the reservoir reservoir by pressing the lever several times; however, you must continue filling the reservoir with liquid. To get rid of air trapped in the reservoir, use a non-metallic lever to collect the brake line.
- Keep the reservoir filled with fluid and when oil starts to flow out of the bleed tube you should close the bleed nipple located in the caliper body.
- The lever should be firm and firm when pressed. However, if any resistance occurs, you should open the screw and continue working with the handle, and then pump oil into the system.
- As the resistance of the lever increases, close the outlet nipple and hold the lever to maintain pressure.
- Use a small adjustable wrench or 7mm wrench to loosen the bleed nipple to open the system. After opening, check for air bubbles in the system.
- Then open the system for a short time to get rid of air bubbles.
- As you add release fluid, press and rate the reservoir reservoir.
- When you are finished pumping, disconnect the hose from the bleed pipe.
Resetting the brake pads
Following are the steps to consider when resetting Shimano brake pads;
- Place the bike on a repair rack and remove the wheels.
- Remove the pad and pad retaining screw. Therefore, use a mild solvent such as isopropyl and a fresh rag to clean both the piston surfaces and the inside of the caliper body.
- Use a plastic lever like a tire lever to press each piston into the caliper body Assess if the piston is moving due to excess fluid in the system.
- Install pads.
- Then install the floating gasket. Shimano part number Y8CL1200 is the most recommended.
- Press the lever several times to center the caliper.
- Never push the lever when installing the wheel.
- Washers should be used when centering pad alignment with rotor. Then fasten the mount with bolts.
- Assess centering by pushing the lever.
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How to adjust Shimano mechanical disc brakes?
The brake motor adjusts the clearances between the brake pads and the disc. Make sure they are between 0.2mm and 0.5mm. For best performance, rotate the adjusting cable drum located on the brake lever as well as on the brake caliper. Adjust both outside and inside at the same time.
Be aware that in addition to braking, contact between the pads and the disc rotor may occur during operation. Also, you may not get enough braking when there is a large gap on one side.
When to replace your Shimano brake?
If the brake surface and rotor are slightly developed, this is a clear sign that you should replace the brakes. However, you can measure its thickness before changing with a micrometer or digital caliper.
If the rotor is badly bent, it is advisable to replace the brake because the rotors tend to bend when they get too hot or are damaged in an accident. However, in other cases, the bend is not visible, but you can see it when the part rubs against the brake pads when turning the wheel.
How to remove air from a SRAM hydraulic disc brake?
It is strongly recommended to protect your hands when handling brake fluid. When bleeding the SRAM hydraulic disc brake, use two syringes with fresh D.O. Brake fluid T 5. The first syringe should be half full and the second syringe. by a quarter. In addition, when filling the syringe with liquid, it is necessary to block the entry of air.
Remove the gaskets and insert the bleed block securely. Once this is done, remove the caliper outlet screw and screw in a half full syringe. After that, open the drain port of the lever, remove the screw and install another needle, push the fluid into the system.
Air entering the hydraulic brake system can lead to poor brake performance because air in the brake often causes unstable pressure in the system when it is hot. over, when braking suddenly, air bubbles can expand, forcing the lever to pump out. Therefore, you should always remove air from the brake system by bleeding.
How to Adjust Bicycle Brakes Friction
Brakes remain the most important safety feature of any bike. If it doesn’t work properly, the rider is not safe. If any malfunction occurs in the brake, repair it immediately. The brake should be checked regularly to ensure that it performs optimally. Handle brake problems carefully. Fix it yourself only if you know how to do it. If you are unsure how to do this, contact your bike master. Eliminate bike and other similar problems that could compromise your safety.
How do I adjust the friction of my bike brakes? Step one
First of all, make sure the friction sound is the result of a brake problem. Make sure it’s not due to a more serious problem.
Place the bike in an upright position, quickly release the bike wheel to make sure the axle is in the correct position in the dropouts.
If the bike wheel is in the correct position, tighten the quick release coupling, this shows that the problem is not friction. If it is ultimately a friction problem, you can continue tuning.
Make sure the wheel axle is in the correct position in the dropout before proceeding with the adjustment.
Next, check if the axle is straight or the frame. If they are, then you straighten them and center the wheels as best as possible. Then clamp the quick release bike and make sure it closes well.
Rotate the wheel of the bike and make sure the clearance between the brake pad and wheel is correct. If the clearance is normal, it means that the bicycle rim is deformed correctly. You can tell when the rim is out of place, when the wheel is actually spinning. If this is the true position, then the bicycle spokes need to be adjusted.
Now that the rim is in the correct position. Check further to see if your bike’s braking system responds very quickly, especially when you push the lever. If there is still a problem with the brake, chances are that the problem is with the brake cables, which may be dry or dirty. In addition, there is a possibility that the brake lever or the lever arm is defective.
If the problem is minor, lubricate the cable with oil, this can restore the brake system and help it work normally.
Make sure debris or dirt is not blocking the pad or touching the bike rim. Check the system very well and if there is anything blocking the system remove them with a screwdriver.
The pads may no longer be in the correct position. If this is the problem, it can affect the braking system and make it work. To determine if the problem is the pad, hold the brake and observe the position of the pads. If this is normal, the position should be such that the entire contact surface is in contact with the bicycle rim. When this does not happen, adjustment is required.
Press down on each brake lever. If they bounce off when you press down, this indicates a serious problem with the brake pads. the problem may be loose springs. In addition, if it does not dangle, then it is missing or broken. The solution to this problem should depend on the type of brakes.
If, for example, it is a V-type brake, additionally check if the spring cable catches the brake lever, if not, then this is a sign of a spring malfunction. It is better to solve this problem with a technician. In the meantime, you can adjust the spring tension. The problem could be that the spring is sheared. When you adjust it, it can return to normal position and the brake will work again.
The problem may be that the levers move back when the brake is applied. There are times when one brake lever pulls the rim. When this happens, the brake may chafe. To fix this problem, look for a spring tension adjuster. This adjuster is a small screw on the brake levers.
You can adjust it with a screwdriver. The tension spring is strong. over, both hands are equal. When you bring it to this position, the brake system works normally again.
How to adjust bike brake pads?
First of all, you need to make sure that the distance between the front fork and the tires is the same. If they are not equal, work with the axle nuts or the quick brake lever. You can tighten them when they are not tight.
Inspect the brake pads. If the brake pads do not come off the rim when the lever is released, apply grease to the caliper pivot. Make sure the grease reaches the rim.
8 FAQs on Brake Pad Adjustment !! Q-1: The brake pad is still rubbing against the rim!
The option described above does not always solve this problem, especially in a situation where the brakes are not applied correctly.
If the brake is still working after applying the solution above, there may be a clearance issue. All you have to do is adjust the clearance between the metal rim and the brake pads.
Q-2: How to know when to replace brake pads?
When the brakes stop responding, the brake pads need to be replaced; if the teeth are worn out, then the teeth with which it holds the brake are gone. When the brake no longer holds, it becomes necessary to replace the brake pad.
Q-3: How to tell if a brake pad is rubbing against the wheel rim and how to solve it?
Normally, both brake pads on a bicycle must travel the same distance before they touch the wheel of the bicycle. If not, then there is a problem, and it needs to be urgently addressed.
8 Frequently Asked Questions About Bicycle Brake Adjustment !! Q-1: How to adjust the brakes on a bicycle?
Answer: There are different ways to adjust the brakes on a bicycle. It depends on the type of brake problem. Check the brake pads before making any adjustments. To adjust it, you need a suitable tool such as a hex wrench.
This can help loose the nuts holding the pillow in place. Then adjust the brake pads by moving them down and up in the holder until you are sure they are in the correct place. Tighten the nuts to hold the pad securely using the same hex wrench. Tighten very well.
Q-2: Why are my brakes rubbing?
Brakes can rub and there are various reasons why the brake is rubbing against the wheel rim or tire. When this happens, it simply indicates that the pad or caliper is out of alignment and needs to be returned urgently. When the caliper is out of alignment or the shoe is also out of place, adjust the system until it aligns again.
Q3: How to adjust the handbrake?
Answer: You can adjust the handbrake when it becomes a problem. It has a bottom nut that can be turned clockwise down the thread. While doing this, pull the rod forward. If it reaches a position where you can pull the handbrake levers up, you stop turning it. Make sure you adjust the other handbrake rod in the same way until they are in the same position. While doing this, hold the hex on the bike cable.
Q-4: Drum brakes are automatically adjusted?
Yes, drum brakes are self-adjusting; do not reverse to do this. If you do not apply the reverse situation, you will find that drum brakes do not take time to adjust to them.
Q-5: What is brake adjustment?
If the bicycle brake system fails, it must be restored. Adjusting the brake system means simply repairing the brake system to get it working again. In most cases, the caliper or brake pad is the cause. When they are not aligned, the brake can rub and the alignment process means adjustment.
Q-6: Can I adjust disc brakes?
Disc brakes can be adjusted like other brake parts. To do this, you need to remove the nuts or bolts that hold it in place and put it into position.
Q-7: Are Grinding Brakes Dangerous?
Grinding brakes are dangerous and occur when the brake linings are worn. This means that the braking system is no longer working. What you do when this happens is replace the pad or caliper or any part of the bike that is causing the problem.
Q-8: How much does it cost to fix the brakes that grind?
There is no specific amount for the repair of grinding brakes. The cost depends on the nature of the problem as well as the type of work. over, the cost of brake parts could vary. It is possible that some users can make this repair themselves, in which case the cost of materials will be required. For many others, they could pay a tech to do it.
Brakes. the most important component of a bike, it needs to be taken care of properly. Don’t let it get out of your hands, as it can cause you serious problems. The above procedures can help solve most of the brake friction problems.
How to install, troubleshoot and set up bicycle disc brakes. detailed manual
Correctly adjusted and tuned disc brakes will allow you to go faster. You can tackle corners and inconspicuous terrain faster if you know your brakes will slow down and stop your bike quickly. If you need something convincing, watch one of these braking videos.
requires much less effort and maintenance than their cable-driven cousins, allowing you to grind more than a wrench. However, even the best water seals sometimes need replacing pads, bleeding air, eliminating squeaks, adjusting the piston, or improving power. Below we describe the elements of proper lever placement, share some of the common problems people face with their braking systems, as well as possible solutions, and suggest ways to increase braking power.
Reliable cable brakes are great for some applications and have a separate full list of problems. Below we will focus on hydraulic brakes.
Disc brake terms
Before we start, let’s define some terms.
Adjusting the distance between the brake lever and the steering wheel. On most modern brakes, the overhang can be adjusted with a pin screw or a 2mm bolt. Visit the brake manufacturer’s website for how to adjust the lever.
Free travel / bite point
Free play of the brake lever. or tilt point adjustment. changes the amount you can pull the lever before the brake pads first touch the rotor.
This is the amount of travel your brake travels between when it was first applied and completely locked. Low modulation means you only need to apply the brake a little before it locks. High modulation indicates that you can move or manipulate the lever over a wider range before the brake locks and your wheels slip. Low modulation brakes are described as being fully engaged or disengaged with little space in between.
This is the part of your brake that clamps the pads to the disc when your finger asks for it.
Plunger (aka piston)
Pistons or pistons. These are metal, ceramic, or composite cylinders that are pushed and pulled by fluid pressure in the brake system. They, in turn, press the pads into the rotor.
Metallic, cermet, organic and polymer
These adjectives refer to the brake pad composition that interacts directly with your rotor The fast story is that resin / organics (different brands use different names) are better for drier weather, they supposedly make less noise than metal pads, they don’t wear out your rotor so quickly and do not last so long. like metal lining.
Metal or sintered pads can help your brakes perform more consistently in wet conditions, last longer than rubber pads, wear out the rotor faster, and sometimes riders find they make an unpleasant noise.
Some people insert a metal pad on one side and a resin pad on the other to get the feel they want from the brakes, which one you choose depends on your needs and preferences, although there are some rotors that require one or the other pad composition.
Steel and alloy based pads
Brake pad liner. this is the part that holds the pad in place, abuts the plunger / piston and conducts the initial heat away from the pad compound. Alloy pads will dissipate heat faster than steel and will cost slightly more as a result.
Mineral oil and DOT liquid
These two fluids are used in nearly all modern hydraulic brake systems to transfer pressure from the lever to the caliper. Mineral oil. this is a fairly general term, although it is most often a by-product of converting crude oil to gasoline. DOT fluids are composed of many elements, and their amount (e.g. DOT3 or DOT 5.1) indicates their tested boiling point.
Left. standard olive and Shimano prong and right. the first step to installing them in the brake hose.
Olives and thorns
These are the parts of the brake system that allow your hose to interact correctly with the lever. A burr is inserted into the end of the brake hose on the lever to ensure accurate fluid movement after the hose is pressed into the lever. Olive. it is a piece of soft metal that is pushed between the lever body and the hose with a hollow bolt that seals one end of the system.
Disc / rotor
These terms are used interchangeably and in tandem to refer to a circular metal plate attached to the hub that the brake engages to slow the driver down.
Bleeding the brake system means removing all air / dirt / water etc. from the system and replace it with the appropriate fluid. Sometimes bleeding involves replacing old fluid with clean fresh fluid, while other times, you only remove a few air bubbles from the system during bleeding.
This is a 4-piston caliper with two calipers on each side (two round nozzles under the XT logo).
Installing the disc brake lever. Distance to one finger
All brake levers on modern mountain bikes are designed to be pulled only with the index finger, loosen the brake clamp just enough to move the lever along the rods, press the brake clamp against the handle and slowly slide it towards the stem an inch or three until the index finger will not naturally rest on the end of the lever during movement. comfortable fit. Your wrist should be straight and comfortable without straining in either direction so that your index finger can rest comfortably on the lever.
This is the optimal reach and tilt angle for my hand size and riding style, I can reach the lever when my hand is fully squeezed and my forearm is in a straight line with my hand.
This measurement is based on riding preference and style, but generally, you want your levers to be in a comfortable position so that your arm and forearm are in a straight line when you sit in your most common riding position. You may have to ride with a wrench to set this angle where you like.
Yeah, this lever is adjusted very low.
Some gravity riders prefer to have their levers in a more horizontal position as they need the brakes most when they are behind the saddle and their forearms are much lower than in pedaling position. In contrast, XC riders who spend a lot of time out of the saddle pedaling often prefer to have their levers close to a 45 ° down angle. Finding a comfortable position so that the stoppers are easily accessible when you need them is important.
At this angle, you can align the levers and make sure they are in the same place before heading out.
You can feel or use a level to ensure both levers are on the same slope. Another trick that works well. is to sit on the bike until you see the brake levers looking over the handlebars, and then select the brake lever element to match the handlebars. I usually use the brake hose as other items may be bent or covered by the drip arms You can use the same arm piece on both sides to align with the steering wheel and determine if the brakes are in the same place.
As with the above, this measurement is somewhat dependent on feel and preference, but there are other aspects to consider: Make sure the reach is adjusted close enough so that you don’t have to loosen your grip on the steering wheel for your index finger to touch the lever. You also don’t want the lever to be so close that it touches the handlebars or your middle finger before fully applying the brake. The ideal place for most people is to place the lever just behind the last knuckle of the fingers (closest to the nail) when it is off.
Here is an example of a lever reach that is too large for my hand size. With this adjustment, I cannot properly hold the barbell while keeping my finger on the lever.
Free travel / bite point
The point at which your lever stops swinging freely towards the boom and the brake begins to actively brake. that’s what is regulated here. If you like adjusting reach near the handlebars, you may need a short free play. Otherwise, your lever will get too close to the handlebars and hit you on your finger or handlebars before fully applying the brake.
Troubleshooting common disc brake problems
Let’s dust it off and start looking for a solution to your brake problems. Once you’ve identified the problem, check the links at the end of this section for step-by-step instructions on how to fix the problem.
I have new pads and rotors, brakes don’t work.
New pads and rotors need to recognize each other through a process called “running-in”. This video should solve your low power problems. If your brakes are still sore after you put them in, you probably need to pump them. In this troubleshooting section, you’ll quickly notice the topic: bleeding solves most disc brake ailments.
My brake makes a scratching metallic sound when I press it.
This sound is most likely due to pad wear, remove the pads and see. If you have less than 3 mm spacers left, they need to be replaced.
Sometimes sand or other debris can get caught in the pillow, causing noise before it wears out. In this case, use clean sandpaper to clean the surface of debris and a needle to remove anything stuck in the pillow.
If at first you fail, bleed, bleed again. Sometimes a second or even a third air outlet is required as air exits from small corners within the system.
My lever feels spongy and doesn’t stretch as close to the rods as it did before.
The feeling of softness or softness in the lever is almost always the result of air entering the system. It’s time for bleeding. Before bleeding, check to see if the pads need replacing. This will save you a step down the road as often replacing a pad also requires a quick release over the edge.
I took out the wheel and I cannot put it back. Insufficient disk space.
If your arm is operated without the disc installed, the pistons may move out of their normal position, which will reduce the amount of space for your rotor and you will need to put the pistons back in place. This video explains how to return the pistons to the caliper.
My brake seems to be losing power. It doesn’t stop me anymore.
A power outage can be caused by several reasons. There may be air in the system and you need to bleed air from the brake, maybe your pads are worn too far, your rotor may be too dirty, or your pads or rotor may be dirty. Before bleeding, make sure everything is clean and free of pads. less than 3 mm of usable material.
Pad glazing can lead to a loss of brake power, especially after a long downhill. Basically, the top layer of the pad material becomes smooth and smooth, rather than rough and grippy due to heat. Remove the pads and rub the surface against a stone or other rough object to restore their shape.
One of my pistons doesn’t move as much as the other and it seems to be stuck.
Pistons move in precise increments into and out of the caliper thousands of times per season, covered in mud, in all conditions of overheating and cooling. Over time, they will start to stick and need to be cleaned.
Rubbing one side of my brake.
If both of your pistons move the same way, but one pad is rubbing against the rotor and the other is not, your caliper needs to be adjusted.
If you are having trouble aligning the brake with the rotor correctly, try adding cup and taper washers to prevent the bolt from defining the angle of the caliper. If this does not solve the problem, you may need to rotate the frame brake pads face to face to ensure a level mounting surface. This is the job of your local mechanic.
The brake caliper makes a noise at a certain moment of rotation of the rotor.
If you hear a scratching or scratching sound at some point while the wheel is spinning with the brake fully disengaged, your rotor is likely bent. Here is a video on how to straighten a rotor. If your rotor flexes slightly, you can muffle the noise by repositioning a vernier caliper.
If you’re driving off-road with a curved rotor, you can fix this with a small stick or tire lever, using the caliper body as a guide. You can also do this with a gloved hand while the rotor is cool and there is no oil in the glove. Rotors can be very hot and sharp, so be careful with this approach.
It is best to clean the rotor with something dull, such as a soft stick. Sharp objects such as pliers can create small creases in the rotor, which negatively affects braking. Adjusting the rotor often requires less effort than you think, so press gently first and check the alignment often. One small bend in the rotor is much better than a lot of bends caused by an impatient repair attempt.
This is a newer rotor, real and ready to grind.
My brakes howl like a stripped banshee whenever they get wet.
Brake whine or squeak occurs when your pads vibrate while engaging the rotor. If this only happens when they are wet, you can try other pad mixes that might work better with your wet rotor. Metal / sintered metal pads often perform better in wet conditions than organic / polymer pads.
Worn rotors with chipped or concave pad contact surfaces can also cause brake whine and need to be replaced.
In addition, there are several products that can be sprayed onto the front or back of the pads to eliminate vibration and noise. I have had good results with this.
Brakes screech constantly.
First, make sure your pads have enough material, there are no dimples or concavities in the pad contact surfaces of your rotors, and that your calipers are correctly aligned. All of these elements can cause brake whine.
If your brakes squeal every time you use them, chances are they are dirty. Often, rotors and / or pads can be dirty from over-spraying chain lubricant or brake fluid from recent bleeding. If you are using chain lubricant spray, try placing a shower cap over the caliper and rotor when applying the lubricant to prevent contamination.
The simplest solution to the problem of dirty pads and rotors is to replace both. Replacing only one or the other usually results in permanent fouling. Alternatively, you can try cleaning them with brake cleaner or setting them on fire.
To burn off dirt, first place the pads and / or rotor on a non-combustible surface. Then fill them with a light dose of alcohol. Light the alcohol and let it burn, hoping that oil or other contaminants will burn out at the same time. Do not allow the pads / rotor to burn for too long as heat can damage them as well. I usually shoot for about 30 seconds.
It is a kind of dirty and concave braking surface that degrades system performance.
It feels like my brake is jumping and not grabbing smoothly.
If you feel the brake lever wobbles or jerks, you probably need to clean the rotor. If your rotor is clean, check for sharp dents or kinks that affect the feel of the lever. You may need to replace the rotor.
I’m in the middle of nowhere and my brakes barely work.
If you are driving on a trail and your brake decides to take a break, try pressing the lever quickly until you feel it starting to work. If that solves the problem, you may have to keep pumping the brake throughout the entire trip to get it working, and then pump it up when you get home.
If your brake system is losing pressure and you need this brake to get home (for example, on a long bike ride), and you don’t have bleeding tools, there is a possible solution. It’s a little risky, but it might work.
This emergency method only works with brakes that use mineral oil as DOT fluids are too toxic and there is a good chance it will break your brake. First, you will need to find out where the brake fluid lost the fluid and repair the leak. Then, using a sealed brake system, remove the brake from the bike and open the vents at both ends of the brake. Submerge the brake completely in the water by shaking and moving until bubbles stop coming out of the ports. When your brake is full of water, close the vents and reinstall the brake. If the system has been sealed, the brake should now work. On long descents, braking performance may decrease as the water heats up and boils over time. Back home, try bleeding the system and see if your brake works. If not, can be hung on the wall as a reminder of this adventure.
I broke the brake lever (or broke the hose, or bent the caliper).
Almost all brake manufacturers offer replacement parts for their systems for much less money than replacing the entire brake. This hose replacement video will help you replace any broken part.
My brake hose rattles, rattles inside my frame.
There may be a hundred videos on this topic, and none of them explain how to fix it. You can try this. If this does not work, wrap the inside of the hose or housing with sealing tape.
Another solution. remove the frame rubber seals that hold your brake hoses and shift cables in place, pull out a few inches of hose and tighten the zip tie firmly on the part of the hose that will be in the frame, then, tightening and not cutting the zip tie, push the cable back into the frame together with tie hole. Do this at both ends of the hose inlet and outlet, then replace the frame rubber seals. The long end of the zipper will press the brake hose against the inner wall on one side of the downtube, keeping it quiet most of the time.
If you are aiming to accelerate on steep tracks, you may also need to increase the braking play.
Once you’ve identified the problem, here are some videos with more detailed repair instructions.
Also, for more information on bleeding, check with your brake manufacturer for their specific instructions.
Power and performance tuning
If you are driving somewhere with steeper trails than your home trails, or your driving style is moving in a more aggressive direction, you may need more power from the brakes. Sometimes a perfectly adjusted brake can be improved with the following changes.
Bleed it (again) If you bleed the brake system quickly, more thorough bleeding can sometimes remove the last bits of air from the system, which will improve its efficiency. Changing the fluid in the brake system once or twice a year will also keep it in top condition and maintain health of the seals inside.
Rotors A larger rotor gives your brake extra leverage to decelerate the wheel faster. Circular plate rotors also dissipate heat better on long descents, providing a more stable overall system. Finally, rotors with steel braking surfaces and alloy centers will cool faster than their steel counterparts and will weigh less. In this case, the old adage “steel is real” is not so positive. Some frames and forks have a rotor size limitation which is often stated on the manufacturer’s website.
Different Pads There are many companies competing for your business in the “best brake pad” market. Some make pads specifically for DH or e-bikes. Using different pads and unique blends can be a good way to achieve the desired brake feel and response.
Other Pistons Nearly every modern braking company offers a 4-piston caliper for gravity driving. If your current brake only has two pistons and you want more, you can switch to a 4-piston caliper. The gravity brakes are really stronger. Here is an overview of the available model from Shimano.
Tire Grip If you are doing all of the above correctly and are still looking for more stopping power, chances are good that the problem is not the brakes. Roughly 70% of your bike’s braking power comes from the front wheel, so make sure you have a grippy tread that’s good for the trails you are riding or racing on. The more grip you have, the more you can brake. Then take a look at the tread blocks on the rear tire. If you want your rear tire to have a lot of grip when braking, you’ll need something with long brake rods in the center of the tread. The Maxxis DHR II is a prime example of a tire that is designed to provide reliable ground traction under braking loads. If you prefer a more responsive outboard motor style rear brake, the E thirteen SS may be better for you.
Here’s a video on how to increase brake horsepower, there are a few more difficult things you can do to increase brake horsepower, but let’s start with them for now.
This list is by no means exhaustive. Please share your braking hacks, fixes, bojs and tricks below.
How to adjust the brakes
Effective brakes are essential for safe cycling. It takes a few tools and just a few minutes to check and fine tune them.
Bicycle brakes become less effective over time. Cables stretch and pads wear out slowly. If you can fully push the lever without applying the brake, urgent action is required. If you are using disc brakes and are experiencing some issues, we have an additional article that you can view here.
Check your brakes
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Is the brake set correctly? V-brakes have a quick release mechanism so the wheel can be easily removed and replaced. The “noodles”, which are a J-shaped metal guide tube, can be detached from the holder. The brake will not work in this state. Side-pull brakes often have a small quick release lever on the caliper to allow it to open wider (as shown) Make sure this lever is closed or the brake pads will be too far from the rim.
Adjusting the cable tension
All cable brakes must have a barrel adjuster. a hollow knurled bolt in which the cable extends from the lever or into the caliper; some bikes instead use built-in adjusters along the outside of the cable.
Turn the barrel adjuster counterclockwise to increase the cable tension. Try doing one full turn first, then half a turn, repeating the brake test periodically. If the barrel evaluator has a threaded retaining ring or lock nut, unscrew this in order to rotate the barrel and then secure it flush with a lever or caliper to hold the barrel firmly in its new position.
Clamp the cable
If a few turns of the cylinder adjuster does not solve the cable tension problem, try re-tightening the cable. First, rewind the barrel adjuster. Then remove the bolt that secures the cable to the brake.
Squeeze the brake with one hand. This is easy with side brakes and V-brakes: just press the brake pads against the rim. When using a cable disc brake, push the caliper brake lever up to apply the brake. The brake does not need to be jammed; just touch the rim or rotor. fine. Do not release the brake until you clamp the cable again.
Then, with your other hand, pull the cable through the cable clamp until the cable is slightly taut. Now release the cable and tighten the clamp bolt.
Finally release the brake.
Since you did not pull on the cable when re-clamping it, there should be enough slack so that the brake pads do not rub the rim or rotor. If the play is too much, use the barrel adjuster. If the cable is too tight and the brake is constantly rubbing, repeat the process above, but do not press the brake completely against the rim or rotor. just hold it tight enough that you can pull the cable further than its previous clamping point.
Sometimes only one of the brake pads will rub. In this situation, you need to center the brake.
Lateral traction brakes often have a small adjustment screw on the top of the caliper on one side. Screw it in or out. slowly so you can watch the brake levers move.
If your bike’s side-pull brakes do not have this feature, loosen the mounting bolt that attaches the brake to the frame or fork, move the brake, then retighten the mounting bolt.
V-brakes have a small screw at the bottom of each brake lever. They adjust the spring tension. To move the brake pad away from the rim, increase the spring tension by twisting it inward. To move it towards the rim, release the spring tension by unscrewing it. Since the position of the brake pads is determined by the tension of the springs on both sides, you will often need to tighten one side and unscrew the other to get the right result. Work in small portions. e.g. half a turn at a time.
Disc brakes, cable or hydraulic, are attached to the frame or fork with two large (5mm) Allen bolts. Turn the two bolts back just enough to manually move the disc caliper from side to side. Then press the brake lever to fully engage the brake. Without releasing the brake lever, use a 5mm Allen wrench in your other hand to tighten the caliper frame / fork bolts.
If the pistons on both sides of the caliper move. all hydraulics and some cable disks. the caliper should now be centered. If, as with most cable discs, only one piston moves, you may need to adjust the stationary position (see below).
Side and V-brake pads must be in line with the braking surface of the rim. Pads set too high will touch the tire and wipe it down; If the shoes are set too low, a projection is formed that can hold the brake shoe against the rim. To adjust the position of the shoe, loosen the bolt on the shoe, then tighten carefully while holding the brake by hand on the rim.
In cable type disc brakes, the piston (and pad) closest to the wheel is usually fixed; it does not move when you press the brake lever, but you can slide or extend it to position it at the desired distance from the rotor. Stretch the spokes with the appropriate hex wrench or Torx wrench, turning counterclockwise to move the shoe away from the rotor and clockwise to move it towards the rotor.
The position of the moving piston / pad is usually only determined by cable tension, but on some brakes (e.g. Avid BB7) it can be shifted or extended independently using a ratchet mechanism.
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