Adjusting rim brakes using the example of V-brake
When set up correctly, v-brakes will perform just as well, and some models even better than disc brakes! The design features of the v-brakes allow adjusting the pads in almost any plane, but this is not possible with caliper rim brakes. The price of rim brakes is significantly less than that of disc brakes, they weigh less and are easier to adjust than disc brakes.
Setting up a budget system: how to properly adjust V-brakes on a bicycle
Ideal for field repairs and cheap to operate, V-Brakes are adjustable in four steps.
- using a hexagon, the screw securing the shoe to the lever is loosened;
- the block is tightly pressed against the rim;
- the search for the optimal location of the shoe is carried out. its outer and inner edges should be coradial to the wheel circumference;
- the block is slightly pulled against the lever.
Debugging the location of the working plane of the shoe. When adjusting the lever brakes on a bicycle, this transition is given special attention: it is necessary to ensure that the front edge of the pads touches the rim before the rear. To do this, under the rear edge of the shoe, fit some solid object with a thickness of 1-1.5 mm and press it against the rim. Then the fixing nut is finally tightened. Next, repeat the transition for the second lever.
Centering the position of the levers (selection of the force of the springs of the levers) The task is to ensure simultaneous adherence of the pads to the rim. Regulating elements. screws located on the left and right levers, near the place where the latter fit on the fork. The cycle of preparation for commissioning includes the following transitions:
Operations on how to adjust the force of the brake springs on a bicycle are as follows:
- clamping the brake lever, the moment of contact of the pads with the rim is monitored;
- on the lever with the block that touched earlier, it is necessary to strengthen the spring by tightening the corresponding screw (you can loosen the spring on the second lever).
Setting the distance of the stationary arrangement of the pads from the wheel rim (selection of the optimal tension of the cable) The task of the stage is to adjust the sharpness of the brake mechanism. The operation is performed in the following sequence:
- the adjusting drum turns almost all the way (you can leave 2-3 threads);
- unscrewing the screw securing the cable to the brake lever, slightly tightening it and tightening the fixing bolt again, the optimal distance between the pads and the rim is found (1-2 mm);
- if it is necessary to slightly increase / decrease the severity of braking, it is enough to unscrew / wrap the drum.
The last brake setting on the bike (point 4) depends a lot on the correct shape of the rim. In the presence of a small figure eight, it is necessary to find the optimal position in which the pads will not wipe the rim. When driving over bumps or holes at high speed, check this setting as often as possible.
Intermediate: Setting up mechanical (cable) disc brakes on a bicycle
Before adjusting any disc brakes, check:
- the accuracy of the wheel axle setting in the dropouts (seats) and the clamping force of the hub in the frame / fork;
- uniform tightening of the brake disc (rotor) and the brake unit housing;
- deviation of the rotor shape from the vertical plane (if necessary, align the rotor with an adjustable wrench).
The technology, including how to adjust disc mechanical disc brakes on a bicycle, is as follows:
- disconnect the drive cable from the brake machine (caliper);
- loosen the two screws securing the caliper to the brake unit housing;
After the adjustment of the working unit of the disc brakes, the setting torque should be adjusted by rotating the adjusting drums near the brake lever and caliper.
For your information. On a properly adjusted deceleration unit, the central vertical section of the brake rotor should lie in the same plane with the caliper slot.
Varieties of rim brakes
Rim brakes are divided into several types:
- V-brake (vector mechanical);
- hydraulically driven.
Caliper brakes. previously popular modifications, are now rare on the market. They are a classic model of rim brakes with attachment to the fork or stays of the bicycle frame. Design features and operating principle:
- Consist of a handle, a drive cable, two movable bows and brake pads.
- The handle is attached to the handlebars of the bicycle, a cable is pulled from it and fixed on the clamping side of the arches. The body itself is attached strictly above the wheel, pads are screwed to the lower mounts of the arcs.
- Through the cable, the force is directly transmitted to the clamping part of the arcs, due to which they are compressed, and the pads are in contact with the rim.
- Responsible for unclamping is an elastic metal insert or spring built between the levers.
The levers have a single axis of rotation and move towards each other like pliers pincers. Hence the name. tick-borne. Advantages. ease of installation, simple setup. Cons. weak braking force, low modulation, high abrasion of the pads, require frequent debugging. Fits on road racing bikes and optionally as a front rim brake on road models.
Cantilevers belong to the second type of disappearing brakes. The principle of their work is to extend the levers under the action of a taut leash. The principle of operation of the cantilever brake:
- Through the main cable, the force is transmitted to the jumper.
- The cable pulls the jumper up, the leash attached to it is pulled.
- The leash connects both levers, which are rigidly attached to the frame.
- Due to the convergence of the levers, the pads approach the rim.
The cantilevers are dirt resistant, will not bump the tire and are easy to install. Significant disadvantages include:
- decrease in braking force as the leash is pulled;
- you need to create a high effort to stop the bike completely;
- difficulty of adjustment.
In justification of the latter, it should be noted that the position of the pads can be adjusted within wide limits.
V-brake is a common type of rim brake on high-speed bicycles. Compared to cantilevers, it has a higher precision and longer shoe longevity. They are also easy to remove and repair yourself.
The vectors are partially similar in design to cantilevers: the front brake levers are bolted to the fork, the rear brake levers are attached to the upper stays. The legs are connected to each other by a pulling cable. The drive cable is brought to one side, but due to the straight shape of the “tie” forces are equally transmitted to both levers.
Hydraulic bicycle rim brakes are a more advanced mechanical model. The drive system consists of a control cylinder, a hydraulic line and power cylinders. The forces from the handle are transmitted to the master cylinder, which, through the oil, acts on the power cylinders. Those, in turn, move the pads towards each other.
Advantages. high compression force and efficiency, excellent modulation. Disadvantages. deterioration of work with a blockage of the hydraulic line, complex repairs. Used a similar type of brakes for freeride and trial.
Rim-type brakes have low brake pad travel, which means they wear less during operation. A significant disadvantage of this approach is the inability to be used on wheels, even with minor rim curvatures. Sensitive brakes will rub against the wheel on the fly, causing reduced speed and increased pad wear.
Useful to pay attention
The braking system is one of the most important technical components of a bicycle. The safety of both the cyclist and other road users directly depends on its condition. Good brakes are essential in any situation, from riding in parks to tough cycling.
In the modern classical sense, a bicycle brake is a pressure mechanism that acts on the wheel rim. In fact, there are several types of brakes, however v-brake (rim) is the most common option on bicycles of various classes.
Adjusting the cable length
Before starting the adjustment, check the brake attachment. In case of slight unbalance, the cable can be adjusted on the handlebars of the bicycle. just tighten the mount on the brake lever with a shaped bolt.
- Checking the positions of the regulators. they must be screwed in the required position.
- In the area where the cable is attached to the brake lever, unscrew the fixing bolt with a hex wrench.
- Unscrew the head screw on the brake lever.
- Remove the cable from the shirt, check it for integrity, replace if necessary.
- Thread the cable back into the sheath, check for freedom of movement.
- Connect the end of the cable with a round attachment to the brake lever and screw the head screw.
- Set the switch to operating mode.
- On the other end of the cable, pull a rubber or aluminum boot so that the narrow part is directed towards the cable. Secure the cable with the fixing screw.
- Tighten the adjustment bolts temporarily.
- Use the pliers to set the optimal level of cable tension: the brake must immediately react to the pressure of the lever.
- Hexagon adjusts the location of the brake pad relative to the disc or rim at a distance of up to 1 mm between them.
- After that, the rotation of the drum and the reaction of the pads are checked, which should not touch the disc when the brake is released.
- When the lever is pressed, the brake pads only touch the disc area.
- After fixing the cable in the required position, tighten the adjusting screw.
- Tighten the adjusters on the brake lever to finish.
After fixing the cable, a small piece of the cord remains, in order to exclude it from entering the bicycle system, it must be wound or cut, leaving 8 cm in stock.
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.
We set the levers symmetrically
In order for the left and right pads 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.
Self-adjusting the brakes on the bike
Cycling is an incomparable pleasure. A constant wind in your hair, a feeling of complete freedom and independence, besides, cycling can replace constant trips to the gym, it’s no secret that riding a “two-wheeled” affects absolutely all muscle groups. First of all, the legs, back, arms, abs. all this is maintained in an active tone thanks to the cycling load. The benefits of a bicycle cannot be understated. But in order to enjoy walks day after day, you need to take care of your “horse”. Preventive maintenance includes adjusting the brakes.
Braking system characteristics
The following terms are used to qualitatively describe the operation of rim brakes:
- impact force;
- wear resistance;
- service requirements;
- comparative features.
Force of impact, or braking, is a parameter that shows how much the brake can clamp the rim so that the bike cannot be moved. Maximum effort is only required to completely stop and lock in place. On the road, the effort is not fully used to adjust the speed. The range of action on the wheel rim by pressing the handle is called modulation, or accuracy, of the brakes.
An active cyclist uses his transport not only in dry and cloudless weather. Rain, mud, sand. everyone who rolls out their bike on long trips will have to face this. The effectiveness of brakes allows you to describe their behavior in a wide variety of conditions.
Durability is a measure of durability, taking into account the prescriptions for the use of the bicycle as a whole. Timely maintenance can increase the service life of the braking system. Service Requirements provide guidance on how to properly install and adjust the machine, how often to do this, and guidance on how to replace parts.
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 be frayed 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.
5 Minute Rim Brake Tune-Up | Cable Tension, Ferrules & Toeing In Brake Pads
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.
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.