How to set up rim brakes on a bicycle. Caliper brakes
Used exclusively on road bikes. Although a more simplified design of caliper brakes can be found on children’s bicycles. They differ from vibracks in that both brake levers are attached to the frame with a single screw. All adjustment comes down to setting the gap between the pads and the rim using the tension on the cable. The most popular brands are Shimano, SRAM and Campagnolo.
Disc mechanical brakes
The most popular manufacturers of such brakes are Tektro, Shimano, Avid. The braking force is transmitted in the same way, but not to the rim, but through a cable and a mechanism called a caliper, to a special brake disc (rotor). The caliper contains brake pads, usually made of metal or synthetic materials. One shoe is usually stationary (internal), the other (external), during braking is pressed against the rotor and presses the rotor against the fixed shoe. However, there are also systems with two movable pads. These brakes are usually found on mountain bikes.
Setting these brakes usually boils down to correctly (parallel) installing the caliper relative to the rotor and setting the clearance between the pads and the rotor using the adjusting mechanisms on the caliper. The simplest brakes may not have such adjusting elements. In this case, the caliper is installed so that the inner (fixed) shoe is as close as possible to the rotor (1-1.5 mm gap), and the outer one is adjusted by the tension of the cable.
The main disadvantage of this braking system is the need for frequent adjustments as the pads wear out.
Disc hydraulic brakes
The most “advanced” and popular mountain bike brakes. They consist of a brake lever, in which there is a piston system with an expansion barrel, a hydraulic line and a caliper, in which there are also two or four pistons that push out under pressure of hydraulic fluid, brake pads.
They are produced by many companies, the most popular of which in our country are: Tektro, Hayes, Shimano, Avid.
There are two main ways to adjust these brakes:
loosen the bolts holding the caliper, by eye to set its position in which the gap between the pads and the rotor on both sides will be the same and tighten the bolts carefully, trying not to disturb the position of the caliper. If the first attempt failed, do not despair, try again.
loosen the caliper bolts so that it moves freely, clamp the brake lever and carefully tighten the bolts. The choice of method is yours.
Automatically adjust as the brake pads wear out, in other words “set and forget”.
If, after correct adjustment, the rotor still “strikes” on the block, the rotor may be slightly bent. In this case, by rotating the wheel, we find and mark the place of the rotor where contact with the block occurs. Then we turn the wheel a little so that this place comes out of the caliper and straighten it with gentle light pressure on the rotor. At the same time, hands must be clean and fat-free.
How to set up and adjust disc brakes on a bicycle
New bicycles are often equipped with rim brakes, or V-brakes, and Soviet bicycles have always been fitted with the only existing caliper brakes.
Currently, this is due to the desire to reduce the cost of the design: it is no secret that many cyclists dream of changing the brakes to disc brakes as soon as possible.
Often, even when choosing a bike, the costs for changing the brake system are included in the amount.
Below, we’ll show you how to set up disc brakes on your dream bike.
Since the principle of operation of disc brakes is different, it is impossible to adjust them according to the same scheme. Brake disc mechanisms are:
- mechanical. In this case, the braking energy is transmitted mechanically, using a cable;
- hydraulic brakes, which have a specially laid hydraulic line, and the braking energy is transmitted by the pressure of the liquid column.
Advantages and disadvantages of mechanical brakes
Mechanical brakes are cheaper, cables and casings (jackets), in which they are located, are quite reliable, more accessible than hydraulic lines. It is also important that the repair of a mechanical brake in the case of a bent disc is easy to carry out on your own.
The main advantage, of course, is easier and more comfortable braking due to the “soft” pressure of the liquid column, “feel” of the handle and control over effort. The hydraulics are more robust with long braking distances, as they are less prone to overheating. Also, these brakes can be adjusted much less often than mechanical.
A significant drawback of liquid-powered braking systems is damage (breakthrough) of the hydraulic line, when service is indispensable.
Mechanical Disc Brake Adjustment
It is necessary to adjust the mechanical brakes when the disc “shorts”, rubs against the pad, or when the braking has become weak.
We start with the brake lever: squeeze it to failure.
If it reaches the fingers, then we begin to limit its free travel: we loosen the lock nut of the machine and turn out the regulator, then tighten the lock nut and check the handle stroke.
If you need to unscrew the screw too much, then first loosen the tightening of the cable. To do this, unscrew the caliper swingarm screw, and after you pull out the cable, turn it back on.
After that, loosen the screws so that the brake moves freely.
After the caliper has become movable, you need to again, as at the very beginning, “squeeze” the brake lever and fix it in this state by tying it to the grip with a strip of fabric or an elastic band.
The clipper is then correctly centered on the disc. 5. Only now we tighten the screws securing the brake machine to the adapter, or plug.
We act strictly one by one, screwing the screws equally, at 25% of the turn. After that, release the handle.
After these measures, we get a perfectly uniform mutual position of the disc and pads, without distortions. Setup finished!
The reason for tuning, as always, is resistance to wheel movement, as well as extraneous sounds, for example, creaking and rustling. Do not forget about a simple check: a suspended and spun wheel quickly stops if the pads touch the brake disc.
- We loosen the bolts on the caliper so that it is movable, then we squeeze the brake handle so that the pads are pressed against the rotor
- Now it is worth checking the position of the valves on the pads so that they stand symmetrically and equally from the rotor.
- Now you need, without releasing the handle, tighten all the screws on the caliper.
- We release the handle, check the operation of the mechanism. In the best case, the pads from the disc should be at the thickness of the hair, but not touching it.
- If the pads are still located at different distances, but at the same time the rotor is ideally placed in the machine, then you can do this: press the disc against the pad that protrudes more strongly, and work sharply with the brake handle about 10 times. The unevenness of the valve aligns the pads, and eliminates the malfunction. It is better to do this together: the assistant presses the disc to the block with both hands, and the other squeezes the handle.
- At the end of the setting, we set the brake lever correctly using the adjusting hexagon. The main thing to remember here is that moving the handle closer to you simultaneously brings the pads closer to the rotor and vice versa.
Let’s say that whatever brakes you choose, you should always be confident in them. And only when all your orders the bike will execute flawlessly, you will get real pleasure.
How to set up rim brakes
Vibrators do not lose popularity. Ease of maintenance, cheap consumables and unpretentious operation. an excellent option for those who use the bike primarily for moving, without extreme and overloading.
The principle of operation is simple. when pressed, the brake lever pulls the cable (G), which moves the brake levers (I), pressing the pads (J) attached to them against the wheel rim. When the handle is released, the levers return to their original position, installed on them by springs. In this article we will analyze how to set up and adjust rim brakes:
Checking the condition of the brakes
First of all, we “unfasten” the brake, as shown in the photo.
Check how the cable (G) moves in the shirt (A) by pressing and releasing the brake lever and pulling the cable back with your finger. the movement should be free, without delay.
If the cable pulls hard, it may be damaged, the shirt or cable guide (C), or dirt has accumulated inside the jacket or cable guide.
They must be removed and cleaned or replaced.
Check the condition of the pads (J). Grooves for the drain of dirt should be visible on them (the block should not be smooth). Worn pads without grooves must be replaced. Check that the pads are complete with washers and that they are correctly installed.
Observe the order of washers when installing new pads.
The brake levers (I) must rotate freely in their seats and spring apart after compression. If the movement is difficult, the brake during operation may get stuck in the closed position and rub the pad on the rim. In this case, you can remove the levers from the seats, clean and lubricate the contact points and reinstall.
When installing, make sure that the protruding pin on the arm fits into the hole in the frame, and that the hole on the left and right arm is the same.
Adjust the position of the pads
“Fasten” the brake by squeezing the levers and placing the cable guide (C) in the stop (D). Loosen the shoe fixing bolt (K) with a hexagon. We press the lever with the block to the rim and set the block so that it:
- adhered to the rim with the entire surface
- did not touch the tire
- parallel to the rim
In this position, the block must be fixed by tightening the bolt. When tightening the bolt, the shoe may move and must be corrected. It will be easier if you find an assistant who will grip and hold the brake lever while you tighten the bolt.
If your brakes squeal, try the following.
Before tightening the bolt, place a folded sheet of paper under the rear (in the direction of travel) of the shoe, then tighten the bolt. So the pads will be smoother to press against the rim during braking (first by the front, then by the rear) and will not “creak”.
We do similar operations with the second block.
We set the levers symmetrically
For the left and right shoes to wear evenly, they must be at the same distance from the rim. Adjustable by spring tension on the brake levers. To equalize the force that returns the left and right brake levers to their original position, use the adjusting bolts located at the base of the levers.
By twisting the bolt clockwise, we tighten the spring, unscrewing it. weaken it. By pressing and releasing the brake, we check the uniformity of the removal of the pads from the rim. Tighten the bolts on the left and right sides until the pads move the same distance when the brake lever is released.
Adjusting the position of the brake lever and the tension of the cable
To bring the brake lever closer to the steering wheel (for example, so that you don’t have to stretch your fingers too much), tighten the bolt on the brake lever.
In this case, keep in mind that you should not bring the handle too close to the steering wheel. It should not touch the grip when fully clamped.
When the position of the brake lever is set, it remains to adjust the cable tension. The task is to bring the pads as close to the rim as possible, leaving a distance of 2-3 millimeters between the pad and the rim.
To do this, you can tighten the cable in two ways:
- For a rough adjustment, if the cable is very loosely tensioned and the pads are far from the rim: loosen the bolt fixing the cable in the brake lever, tighten the cable, tighten the bolt. While loosening the bolt, hold the lever and cable so that the cable does not “run away” and do not have to re-thread it into the seat.
- for fine adjustment, use the adjusting screw at the point where the shirt comes out with a cable from the brake lever. To make the screw spin freely, loosen the lock nut by unscrewing it counterclockwise. Turning the screw clockwise, we release the cable tension (the pads move away from the rim), unscrewing it counterclockwise, we increase the tension (the pads are closer to the rim). When the pads are in the desired position, tighten the lock nut.
That’s all! Checking how everything works. If necessary, re-adjust the springs of the levers (item 3).
Steering wheel adjustment.
The steering wheel control depends on the correct position of the handlebars. The handlebars are considered to be correctly adjusted if the hands, elbows, back and neck of the cyclist do not strain or stiffen when riding in a comfortable position. To achieve this, it is necessary to adjust the height of the handlebar and its tilt, following the following rules:
- On a road bike, the handlebar should be at an angle of about 90 degrees. To do this, it must be installed directly above the front hub (center piece of the front wheel).
- On a mountain bike, the handlebar tilt is 45 degrees, in which case it is set an inch (2.54 cm) in front of the hub.
- Road bar height adjusts 3 inches above saddle height and mountain bike adjusts 4 inches lower.
It is impossible to tune a speed bike without adjusting the saddle position. Only by correctly positioning it, you can feel comfortable while riding, it will be easier for you to start moving, get on and get off the bike. The following parameters are regulated:
- Saddle height. To determine the desired position, you need to sit on the bike, put your foot on the pedal and move it to the lowest point. The leg should be free to reach the pedal, but be fully extended.
- Tilt angle. The saddle is parallel to the ground or not more than 3 degrees to one side or the other.
Setting the speed switches.
The question of how to adjust the speed switch on a bicycle arises from the vast majority of fans of two-wheeled vehicles. Modern bike models are equipped with two switches. front and rear. To configure them, you must:
- install the chain on the smallest star in the front and the largest in the back;
- rotate the screw, setting the frame in such a position that the chain will be located as close as possible to the inner plate, without touching the frame when pedaling;
- transfer the chain to the smallest back and largest front sprockets;
- rotate the other screw, setting the frame to a position in which the chain will be located as close as possible to the outer plate, without touching the frame when pedaling.
To finally set up the front derailleur, its foot must be installed 2-3 mm above the chain and adjust the cable tension. Rear derailleur adjustment begins with setting the chain to the largest sprocket. It should move down one click. If this does not happen, it is necessary to slightly loosen the cable by turning the drum clockwise. You will know that you are able to fine-tune your bike’s gear shifting when the chain moves softly and quickly up and down the sprockets, both front and rear.
This usually ends the bike adjustment. It remains only to pump up the wheels, and you can go for a walk or a trip out of town. If you have additional questions. how to adjust the speedometer or bike fork, how to properly care for the bike or any others. you can always contact the specialists for additional advice.
Adjusting the foot brake | Brake system
When servicing vehicles, there are two types of brake adjustment:
- the current
The current adjustment is to maintain the effectiveness of the brakes by restoring the normal clearance between the friction pads and the brake drum and adjusting the pedal free play.
Before starting to adjust the brakes, it is necessary to check and eliminate jamming in brake control mechanisms, mechanical damage, oiling, wetting with brake fluid, etc. The gap between the brake drum and linings is adjusted in various ways, depending on the design of the brake.
In the presence of adjusting eccentrics (GAZ and UAZ cars), the front wheel of the car is pre-hung and rotated by hand forward, and the adjusting eccentric 1 of the front shoe is gradually turned with a key until the brake shoe is pressed against the drum. Then the eccentric is turned in the opposite direction until the wheel begins to rotate freely. In the same sequence, adjust the gap between the rear shoe and the drum, while rotating the wheel backward. In passenger cars, when adjusting the rear block of the front wheel, it is rotated forward.
In cars with pneumatic brakes, the clearance is adjusted by changing the position of the expander 1, rotating the worm 2 of the adjusting lever. The need to adjust the clearance is determined by the length of the stroke of the brake chamber rod; the stroke of the rod should not exceed 35. 40 mm. (ZIL-130 — for front 25 mm and rear 30 mm). The smallest stroke of the rods after partial or complete adjustment of the gap should be 15 for the front and 20 mm for the rear cameras. A full adjustment is made after repairing the brakes (for example, after changing linings). In this case, the required clearance is set not only in the upper part of the shoe, but also in the lower (support) one. This gap is adjusted by turning the support adjusting pins 2.
Adjusting the free travel of the brake pedal with a hydraulic drive with adjusted gaps between the pads and the brake drum is to establish the required clearance between the piston pusher 4 (rod) and the piston 5 of the main brake cylinder itself. This clearance, which protects against spontaneous braking of the brake pads, is determined by the amount of pedal free travel and, depending on the drive design, ranges from 1.5 to 2.5 mm, and the pedal free travel. from 6 to 17 mm.
The gap is adjusted by changing the length of the pusher by screwing its hex nut 3 onto the connecting rod 1 with a loosened locknut 2, or by turning the eccentric pin connecting the pusher with the pedal.
The amount of pedal free travel can be checked using a special ruler.
Adjusting the free travel of the pneumatic brake pedal consists in setting the required length of the rod connecting the pedal with the brake valve lever.
Free travel of the upper end of the brake pedal should be 15. 25 mm (with the combined crane of the ZIL-130 car. 40. 60 mm). With full braking and operating pressure in the system, the pedal should not reach the floor by 10-30 mm.
Adjustment of the manual central brake consists in setting the gap (0.5. 0.8 mm) between the pads and the disc or drum. The clearance is adjusted by changing the position of the brake pads with adjusting bolts or nuts, as well as the length of the rod connecting the pad drive lever with the hand brake lever.
Brake system adjustment
Construction machinery and equipment, reference book
Kamaz Ural cars
Brake system adjustment
Effective braking of machines is ensured by adjusting the brakes.
The brake mechanism of the service brake system is adjusted to restore the normal clearance between the friction linings and the drum. Brake adjustment can be full or partial.
Full adjustment is carried out after repair of the brakes (replacement of friction linings or pads) or violation of the centering of the working surfaces of the friction linings and brake drum. It is produced using the supporting eccentric axes of the shoes and the axes of the adjusting levers or adjusting eccentrics. In this case, the 0.1 mm thick dipstick must not extend along the entire width of the brake pads. The gap measured with a feeler gauge in the upper and lower parts at a distance of 30 mm from the edge of the linings should be within 0.2. 0.4 mm.
To obtain the same braking efficiency of the right and left wheels, one should strive to ensure that the strokes of the rods of the right and left chambers (K.amAZ-5320, KamAZ-4310) on each axle differ little from each other and are within 20. 30 mm.
Partial adjustment is performed only with the help of the worm axles of the adjusting levers (KamAZ-5320, KamAZ-4310) or eccentrics (Ural-4320) to reduce the gap between the linings and the drum, which increases during operation due to wear of the linings. The presence of large gaps, which require partial adjustment, is detected by an increase in the stroke of the brake chamber rods (the stroke of the rod should not exceed 30 mm). When adjusting the brakes, the stroke of the rods is set equal to 20 mm, and for the left and right chambers of each axle, they should differ little from one another.
The clearance between the friction linings and the brake drum of the parking brake system (Ural-4320) is adjusted by moving the adjusting lever on the expander shaft clockwise by one or two teeth. The gap between the linings and the drum should be within 0.3. 0.6 mm. In this case, the gap between the lever and the brace of the brake valve drive must be no more than 2 mm. With a correctly adjusted brake, the lever pawl 3 is installed on 3. 5 teeth of the sector.
Free travel of the brake pedal (15. 25 mm) of the Ural-4320 is regulated by changing the length of the rod. In this case, the drive lever must be pressed against the stop of the upper cover of the brake valve. The start of the working stroke is determined by a significant increase in effort.
Read more: Characteristics and arrangement of the cab of the KamAZ-5320 and KamAZ-4310 vehicles
Setting and adjusting brakes on a bicycle. disc and rim, mechanical and hydraulic.
Before moving on to the main question of how to adjust the brakes on a bicycle, we will single out several types of them: disc, hydraulic, rim. Thanks to the large assortment on the market, every cyclist will be able to choose exactly what they like best. Any of the options presented equally fulfill the tasks assigned to them, namely, knocking down high speed. The difference between them is only in the contact surface. If discs are bought for damping high speeds, then for other types they buy brakes that are in direct contact with the rim itself. These braking elements can be of different sizes, on which the contact area itself depends. As a rule, the larger it is, the better the wheel speed reduction is achieved.
Adjusting mechanical disc brakes on a bicycle.
Disc brakes are becoming popular today, and the craze for them began about 4 years ago. It’s not about reliability at all, but about the fact that their presence on the bike gives the impression of a racing motorcycle or emphasizes the coolness of the owner of such a bike.
The main features of disc brakes:
- overcome high speeds;
- brake without locking the wheels;
- do not wear out the rim;
- do not pay attention to weather conditions.
Adjust disc brakes as follows:
- check whether the cable responsible for the operation of the disc brake is in place, because sometimes it may be out of place and this is the reason for difficult driving;
- see if the wheel is correctly placed in the frame itself;
- tighten all the bolts securing the brake to the rear or front fork;
- check the tightening of the screws on the wheel hub;
- set up movable and static pads;
- we loosen the bolts holding the brake machine with pads;
- we clamp the brake lever (if you don’t have someone to help, then fix the handle on the handlebars with a rope);
- after that, the pads should fit under the disc;
- tighten the screws.
Adjusting and adjusting hydraulic brakes on a bicycle.
You can use a sheet of white paper to adjust the disc brakes. It requires you to put it behind the disc and this will make it possible to adjust the gap between the rubber main pad and the disc itself. As a tool, you can take 4 mm and 5 mm hexagons, a ruler, a Phillips screwdriver. We do all the initial steps, as shown in the example with mechanical disc brakes, and turn the screws until you feel that they no longer lend themselves to clamping. On all bicycles with this type of braking system, the discs are slightly bent and friction will be heard while riding. This can be avoided with an adjustable wrench, that is, they need to slightly bend the base of the disc in order to achieve absolute evenness. But after riding the bike for a long time, they deform again. We check the location of the adapter itself and tighten the bolts again. If the machine itself is slightly offset to the side, then it is necessary to loosen them and substitute a white sheet of paper. We estimate the clearance between the pads and the disc and tighten the bolts back.
How to bleed hydraulic brakes on a bicycle. video.
- pumping the disc brake system begins with unwinding the master cylinder, and after installing it in a horizontal position;
- remove the cover from the cylinder itself (in most cases, screws with cross-shaped slots are used for fastening);
- we run the brake fluid on a mineral basis through the system;
- make sure that there are no air balls;
- we install the device with liquid in the inlet nipple (exclude it from getting on the bicycle paint, as the composition may contain components that corrode it);
Setting and adjusting rim brakes v brake on a bicycle.
In the overwhelming majority of cases, v brake is installed on budget bicycles, walking and children’s bicycles. These are rim brakes with acceptable power and modulation. no wheel locking occurs. Before starting work, you must provide yourself with the following tools: a 5 mm and 3 mm hexagon, a screwdriver, and pliers.
Features of setting v brake:
- unfasten the brakes themselves;
- the main requirement is to put the wheel in a level position;
- return everything to its original position;
- tighten the cable with a hexagon and pliers;
- if the handle stroke is large, then it is required to tighten the cable even more and strengthen the brakes themselves;
- we check the wheel speed. the course must be free. It happens when thorns are heard, then in this case it is worth adjusting the spokes themselves;
- if one brake surface v brake is closer to the rim than the other, take a screwdriver and release or tighten the forcing shoe screws.
Above, brief instructions were presented for those who like to consolidate their knowledge not only with the help of videos, but also in text format. Bicycle brakes, types, settings. are present in this article. Each brake system is accompanied by an introductory instruction, especially its complex types. the hydraulic version. For them, there are restrictions in the selection of fluid and if you do not follow the advice, then neglect and pouring anything in will lead to injury and nervous stress. If you do not want to visit a traumatologist, follow the rules. Any type of brake will wear out over time and must be replaced. Practice shows that disk modifications are less vulnerable and can last for a long time. If they are incorrectly adjusted, the clamping index between the front and rear brakes will be different. Some will say that the reason is in the length of the cable, since the front part is half the length of the back. If the cable is not completely closed, then try to lubricate it. The fact is that inside the rubber hoses there is a steel tube, which is responsible for the smooth and free sliding of the cable. Over time, it rusts, and this leads to ruptures and unweaving, and in order to avoid such a nuance, it is advisable to apply a few drops of machine oil or grease to it.