How to find out which pads are on a bike

What are the sizes of bicycle wheels?

The geometric parameters of bicycles differ according to a strict pattern. this also applies to the size of the frame and the diameters of the wheels. First, let’s present a size table:

Wheel, inches / mm Rim, mm Bike
20/508 406 Children’s, teenage, folding, BMX
24/609 507 Teenage, foldable adult
26/660 559 Mountain
28/711 622 Road, hybrid, highway
29/736 622 Mountain niner

The first column shows the traditional wheel diameters in inches and millimeters. The wheel is measured with the tire. To find out the size of the rim, you need to double the height of the tire. Standard rim sizes are shown in the second column.

  • classic, in inches;
  • in centimeters;
  • ISO standard, in millimeters.

The International Organization for Standardization (ISO) has implemented a universal wheel measurement system to avoid confusion. All bicycle manufacturers adhere to it. The dimensions of the wheels are made up of the diameter of the “clean” rim and the width of the tire profile.

When choosing new tires, you need to know the rim landing diameters. these numbers on the tires must correspond to them. This will come in handy when changing to a different tire profile. In everyday life, a wheel is measured in inches, and it is more convenient to give dimensions in inches. And by the size of the wheel, you can also determine the type of bike. walking, mountain or road.

Wheel sizes are important to know when choosing a child’s bike. There is a direct relationship between the numerical values ​​of diameters with the height and age of the child, the so-called “wheel size”. Below is a table of standards:

Diameter, inches Height, cm Age
12 up to 98 3
14 98. 104 3. 5
14, 16 104. 110 4. 5
16, 18 110. 116 5. 6
20 116. 128 6. 8
24 up to 164 over 8

Wheel sizes for kids ‘bikes are separate from adults: kids’ range ends on 24 “wheels, while for adults it just starts (excluding 20” BMX). 24-inch wheels can be safely attributed to teenage and universal (for small adults). Of course, this data will only help you choose a bike, otherwise you need to try it on.

Methods for measuring wheel diameter

The very essence of measurement comes down to obtaining numerical data. centimeters, millimeters or inches. It can be done in several ways:

  • measure the radius;
  • ISO;
  • through the circumference.

The easiest is the first way. We take a centimeter or tape measure and place the bike vertically so that it does not fall. Place a zero straight edge on the hub axle and hold it to the edge of the tire. This will be the radius of the wheel in centimeters. Then we multiply by two. we get the diameter. To get millimeters, you need to multiply by 10, and inches by 2.54.

ISO will measure the diameter and rim and height of the tire profile. This method may be necessary if you need to put a tire of a different profile. several types of tires can be selected for the same rim diameter.

Only measure the distance from the center of the hub to the outer edge of the rim. Knowing the radius, we multiply it by 200. we get the diameter in millimeters. And we pick up another tire on it.

The third method shows how to determine the diameter in terms of the circumference. For these purposes, you will need a cable and a tape measure. We wrap the tire with a cable, make a mark at the junction with the beginning of the cable. We straighten and use a ruler to measure the distance from the beginning of the cable to the mark. This will be the circumference.

  • Apply a staple mark of paint to the tire.
  • Place the wheel so that the mark is in the lowest position.
  • Ride one turn.
  • At the bottom, the paint will be erased from the tire, and on the sides it will remain, you can understand that the wheel was rolled exactly the opposite.
  • Measure the length of the filled line.

Do not be afraid that for large wheels this value will exceed 200 cm. First, divide it by 3.14. we get the diameter in centimeters. And then divide by 2.54 to convert to inches. Actually, it’s so easy to find out what size the wheel of a bicycle is.

When measuring with a ruler, you will most likely get fractional values, for example, 28.23 inches. Round to whole values ​​taking into account the existing diameters.

How to measure the diameter of a bicycle wheel

Sooner or later, the cyclist is faced with such a concept as the size of the wheels. This may be already at the time of buying the bike or the first time you replace the punctured tube and tire. How important is it to know the geometric parameters of the “running” bike? Nothing less than going over the bushing or lubricating the chain.

Determining the diameter of a bicycle wheel is very simple. We will talk about this in our article. Of course, this parameter is most likely to be recognized precisely from the moment of purchase or in the process of “studying” their two-wheeled friend. Nevertheless, suddenly he is unknown for some reason, for example, they gave him a ride for a while, and then the tire went flat, and it is necessary to put a new camera.

Bicycle tire markings

And now a little about tires and their meanings. According to the classical system, the dimensions are applied in the following order: wheel diameter in inches / tire profile width.

According to the international ISO system, the same parameters are stuffed onto rubber in the opposite order. first the profile height, then the rim landing diameter. Values ​​are in millimeters. For the same tire or tube 20 / 1.75 in ISO it will look like this: 44.4 / 406.

The table below shows the ranges of the profile heights of tires for the landing diameters of the rim:

Standard markings Rim, mm
20 / 1.5. 2.125 406
24 / 1.5. 2.125 507
26/1. 2.35 559
27/1. 1.75 622
28/1. 175 622
29 / 1.75. 2.35 622

The listed tires can be selected for one fit size. However, it is better to take into account the recommendations of the bike manufacturer in the passport and adhere to the recommended parameters. Tires that are too narrow will puncture more often, while tires that are too high increase resistance to movement and can damage the sides. Each rim has its own tires. Optimum matching of tires to wheel sizes will allow you to ride longer, without punctures or damage.

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Road bike chain length

For road bikes, there are usually 3 ways to determine chain length. This is a method in which the chain is placed on a large chainring and a small rear.

Old and new types of bicycle chain

There have been many revolutions in bicycle design in the past fifteen years. Some of them have become noticeable and striking, for example, the emergence of a new type of bicycle. mountain, disc wheels and new designs of handlebars. Other innovations were not as noticeable, but no less significant, such as the introduction of clip-on pedals, bicycle computers and index gear shifting.

The same little-noticed revolution has taken place in bicycle chain designs. Many people don’t pay much attention to bicycle chains. From the outside, they all look the same. What’s interesting to look at is the switches, and there is a lot to discuss. The most interesting thing is that the circuit is the element under which all switches are designed.

In old-style bicycle chains, there are ten parts for two half-links. The standard chain used on a multi-speed bike has 114 links and 570 parts. more than the rest of the bike. The chain has 114 inner plates, 114 outer plates, 114 rollers, 114 cups (bushings) and 114 rivet shafts.

Read more Old and new types of bicycle chain

Bicycle chain wear

After the brake pads, the chain is the most worn-out part of the bike. With long-term use, the chain stretches due to the appearance of play between the holes in the plates and the pins where they are pressed. Bicycle chain wear occurs for several reasons:

Chain misalignment with different gear options. 2. Loads arising in the links when the chain moves from one star to another when switching.

Since the chain works in an open state, dust, dirt and other objects falling into the links, due to friction, increase chain wear.

On bicycles, roller single-row chains with a link length of 1/2 inch. 12.7 mm are used. Ideally, a new chain should be 12.7 times the number of links in the chain. How to find out the state of chain wear in order to control the situation and change the chain in time, extending the life of the cassette?

Take a section of the chain with the number of links in it. 20. Multiplying the number of links by the length of the standard link of 12.7 mm, we get the size of the section of the new chain of 20 links, equal to 254 mm. We take a ruler and measure.

Read more Bicycle chain wear

How to determine bike chain wear

Take a section of the chain with the number of links in it. 20. Multiplying the number of links by the length of the standard link of 12.7 mm, we get the size of the section of the new chain of 20 links, equal to 254 mm. We take a ruler and measure.

Panic Brake Test. Does Brake Pad Compound Really Matter?

The photographs show that the distance between the extreme centers of the 20 links is approximately equal to 254 mm.

In this photo, the distance of the 20 links is just over 255mm. The difference between the first and second case is 1.1 mm or 0.45%.

How to find out which chain on a bicycle

articles on bike chain:

Bicycle chain slip

Sometimes bicycle pedals will slip, especially when a lot of force is applied to them. This phenomenon is even more common when the cyclist stands on the pedals. To avoid chain slipping, the rider has to downshift and stay in the saddle instead of standing in higher gears.

Very often the switch is blamed for slipping and jumping the chain, as well as spontaneous gear shifting, but the phenomena that were listed above are very rarely caused by its improper operation.

Chain overshoot causes one of two unrelated phenomena. direct overshoot and spontaneous gear changes. The main thing, in order to solve the problem, it is necessary to determine what exactly comes from the two cases.

Read more Bicycle Chain Slip

Operating principle

Let’s consider the principle of action in stages and as simple as possible. With a bike with a good braking system, the principle can be easily seen and understood.

  • By pressing the brake lever, the brake cable sets in motion a special mechanism.
  • The mechanism is quite simple, when the cable is pulled, it begins to adhere more tightly to the braking surface of the rim (for V-brakes) or the rotor (in disc brakes). Surfaces that fit snugly are the very pads.
  • At the last stage, they begin to adhere tightly to the surface and slow down the rotation of the wheel. The tighter the rope is pulled, the stronger the friction, which means the faster the wheel stops.


The recognized giants of the cycling industry over the past 10-20 years are the American company Sram and the Japanese company Shimano. Chinese and Taiwanese manufacturers (for example, Artek), of which there are dozens, are also striving to improve the quality of their products at least to the Japanese level, and not without success. Some thrifty consumers cheerfully report about a very good brake resource for not too extreme riding, for example, on a walk or on long bike trips, bike trips.

With a simple V-brake from Shimano, mounted on a cheap mountain bike for 10-20 thousand rubles, you can easily drive 1000-2000 kilometers on trails (and being passing through cities along the way), and still change worn out pads.

You can guess about their wear both by the sharply decreased braking effect and by the loss of smooth contact. Perhaps the “rubber” squeak will change to a metallic clang.

Whichever brake you choose and how long it lasts, do not skimp on safety. The brakes were invented not so much by cowards as by those who would not want people to lose health or even life because of their absence. As soon as braking has significantly deteriorated due to wear of the rubbing surfaces, change both the pads and the rims themselves (discs, drum bushings).

Next, watch a video on how to replace or install brake pads on bicycle disc brakes.

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V-brake installation

Replacing brake pads on a bicycle is a simple process. For a V-brake, the procedure is as follows:

  • The handles must be installed on the steering wheel. To fix them, you should choose a convenient place.
  • Then you need to stretch the cables and insert the levers into the grooves.
  • Then you should press the levers against the brake system and fix. The distance from the pad to the rim should be 1-3 mm.
  • Next, the operation of the system is checked.
  • Before installing the levers, it is advisable to lubricate the grooves with oil. These parts must be at an equal distance from the rim for uniform wear.
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Installing disk

Replacing disc brake pads on a bicycle is carried out in the following way:

  • The brake levers must be attached to the steering wheel.
  • The caliper is installed in its place.
  • The rotor must be fixed to the hub.
  • The cable must be passed from the handle to the caliper.
  • The pads are inserted into the caliper and then locked.
  • The pads need to be adjusted with special bolts. Their distance should be 1 mm.

Thus, the purchase and installation of a braking system is a key factor in ensuring the safe operation of vehicles. To choose the right model, it is advisable to consult with the seller. It’s important to choose the right brake pads for your bike.


V-brakes are the simplest V-shaped brakes that are operated with a cable. The rim itself acts as a brake disc without any additional layer or other base. The levers of such a brake are extremely simple. they resemble the closing parts of a spring-loaded caliper. As with all brakes, the pushing force from the brake lever on the handlebars is transmitted by a cable encased in a “jacket”. a waterproof plastic tube that prevents scratching and premature rusting of steel strands.

The rim brake pads are here screwed onto the caliper elements using bolts, nuts and lock washers. It is important not to confuse left and right. the pads are curved to the shape of the rim, and do not stand straight like bars, which makes it possible to brake faster and more efficiently. The midline of the pad matches the midline of the rim.

At the same time, the rim itself has a corrugated, “pockmarked” surface, and this “ripple” is parallel to its outer circumference, which allows the shoe to quickly rub in and “wedge” into it during braking, creating an extremely large contact area of ​​the rubbing surfaces. The dimensions of the rim do not really matter. the effectiveness of rim brakes does not differ significantly with different wheel diameters.

The V-brake shoe, although it has a steel base, has a polymer layer on the side of the braking surface. most often plastic or composite. Although the V-brake manages to stop almost instantly, this layer wears out quickly due to the high angular velocity of the rim. It is several times larger than the braking surfaces of other types of brakes, in which the rubbing layers are much closer to the center of the wheel (hub). Only the pads themselves are replaceable, then the cables are located according to the frequency of change.

The V-shaped brake caliper can be left in place for several years. it is considered the most durable part, as are the handlebar grips. However, as you continue to ride with worn out pads, you scrape off the aluminum layer by layer that makes up the rim, and it will eventually bend significantly at full speed, if not break. The latter is already life threatening. For the highest level of safety, rim brakes come complete. front and rear.

What are bicycle brake pads and their maintenance?

Every cyclist wants his two-wheeled servant to ride as easily as possible and pick up speed as quickly as possible. The speed indicator, undoubtedly, has a huge weight, but the bike must be stopped clearly and in time. And if the dynamics of movement depends on many factors, for example, type, weight and dimensions, then a quick and smooth decrease in speed is provided by an effective braking system.


These brakes are the most popular and are fitted to most bicycles. It is quite cheap and simple, but reliable at the same time.

V-brakes are most often installed on city, children, and also budget bicycles. Everything is clear here, on such bicycles the speeds are not very high, sharp braking is very rarely necessary, and most importantly, the brakes are not used so often and wear out for a long time.

Let’s consider the main components of this mechanism:

  • Brake handle. Installed on the steering wheel and starts the entire system.
  • Cable. Transmits tension and converges levers.
  • Levers. Mounts to front fork (front) and chain stays (rear).
  • Brake pads. Attached to the levers and directly in contact with the braking surface.

As you can see, the mechanism is very easy to use and maintain. The pads here have an oblong shape. Most often they are made of special dense rubber, which is fixed on a dense iron or plastic base.

V-brake installation

Replacing brake pads on a bicycle is a simple process. For a V-brake, the procedure is as follows:

  • The handles must be installed on the steering wheel. To fix them, you should choose a convenient place.
  • Then you need to stretch the cables and insert the levers into the grooves.
  • Then you should press the levers against the brake system and fix. The distance from the pad to the rim should be 1-3 mm.
  • Next, the system is checked.
  • Before installing the levers, it is advisable to lubricate the grooves with oil. These parts must be at an equal distance from the rim for uniform wear.

Operating principle

Bicycle brake pads work according to the following principle:

  • After pressing the brake lever, a special mechanism is set in motion with a cable.
  • The mechanism is simple, with tension on the cable it will fit snugly against the braking surface of the rim (if V-brake) or the rotor (if disc brakes). Close-fitting surfaces are pads.
  • At the final stage, they adhere tightly to the surface, the rotation of the wheel slows down. The friction force depends on the pulling force of the cable, as well as the stop of the wheel.

A working braking system on a bicycle is a guarantee of safety. But for a general understanding, you need to know how it is installed and works. Bicycle brake pads are considered an important part. They will be discussed in the article.


These brakes are considered the most popular as they are found on most bicycles. They are cheap and simple, but reliable. They are usually installed on urban, children’s, budgetary modes of transport. These bicycles are slow, so you don’t need to brake hard.

  • Brake lever. It is attached to the steering wheel and starts the entire system.
  • Cable. Thanks to him, the tension and reduction of the levers are transmitted.
  • Levers. Fits on the front fork and chain stays.
  • Brake pads. Fastening takes place on the levers, the parts are in contact with the braking surface.

General information

  • Transport type. For walking, children and amateur types, you should not choose expensive devices.
  • Brake system type. Depending on this, the pads may differ in shape and size.
  • Frequency of use. After all, it really matters how often transport is used. several times a year or regularly.

Squeaking brakes

Often on bicycles, the pads squeak strongly during braking. With strong gripping, along with the sound, the vibration of the braking surface and the spinning of the wheels forward. In the latter case, there is serious damage to the linings due to wear: the pressure elements rub over the rim, but they cannot clamp it, so the wheel slips. In case of harsh sounds, do not operate the system, you need to find out the cause of this phenomenon and eliminate it.

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Unpleasant sounds appear on rim and disc braking systems. The reasons for this phenomenon are as follows:

  • Dirty disc or rim.
  • Oiling the pads.
  • Pads material stiffness.
  • Wear.
  • Inappropriate position relative to the rim.

When squeaking, you need to pay attention to the surface: this phenomenon is observed due to the accumulation of dirt, grease and moisture. Cleaning is carried out with a solvent: white spirit or gasoline. Then the parts are wiped with a dry, clean material.

Do not discard linings when oil builds up on the brake surface. They are calcined until the spots burn out. This is done on a heated surface or above the burner. After the disappearance of traces, the pads are left in the open air. With such a procedure, they will not serve for a long time, but high-quality options, for example, from Shimano, withstand heat and can be operated for a rather long period.


Bicycle disc brake pads are rare. The parts are expensive but durable and reliable. There are more of them. These items are considered difficult to install and configure. Usually they are attached to expensive models of vehicles, road and other sports bikes.

  • Handles and rope. They are the same as in the previous version.
  • Brake disc. Fastening to the hub with 6 bolts.
  • Adapter. Is a mechanism for securing the caliper to the frame.
  • Caliper. The block is operated with the part.
  • Block. They press the disc, and therefore braking is applied. In this system, they are round.

Types of brakes

  • Drum.
  • V-brake.
  • Disk.

A vehicle with drum brakes is rare. They work differently from the rest of the species. This system has been known to many since childhood. It is considered expensive to repair, so it is rarely installed.

Bicycle brake pads: maintenance, replacement, wear detection

The bicycle quickly began to gain popularity among ordinary citizens. But before leaving for each walk, you need to carry out a small technical inspection. It is worth constantly monitoring that all the necessary nodes are in perfect order. The outcome of the walk depends on this: will it be pleasant or not. Well, what system guarantees safety when driving? Of course, the brakes. Today we will talk about what systems are, how to replace brake pads for a bicycle and many other nuances.

Rim brakes

Here the device is a little simpler. The role of the caliper is performed by two levers that clamp the brake pads, thereby stopping the wheel.

How to determine wear on bicycle pads

The fact is that before replacing the brake pads for a bicycle, it is best to check for wear. Suddenly they are still suitable for such a service. In general, good manufacturers make special notches on their product, which help determine the wear of the system. When the pads are worn out so much that the cuts themselves will no longer be visible, then this is a signal that it is time to change them. But before replacing a worn out element, you need to ask the question: “What affects their service life?”.

First of all, the number of kilometers and riding style affects durability. Everything is clear, the more you ride, the more the pads are torn off. Compare a person who loves simple and leisurely walks in his city, or a cyclist who cannot live without a headlong descent from a mountain and an active ride along forest paths. Therefore, much also depends on the driving style.

In fact, these tips for prolonging the life of brake rubber are needed only by those who are serious about cycling or very enthusiastic people. The fact is that good brake pads live on average fifteen thousand kilometers, and some even more than thirty thousand kilometers. It seemed to ordinary people now that there was some kind of mistake, but no. In fact, for hobbyists, these are just a couple of cycling seasons. But ordinary people who just like to go out into nature on weekends also need to replace these nodes, but not because they travel so much. As a rule, beginners make some mistakes that lead to rapid wear of the braking surface. Is it possible to do so as to change the pads as rarely as possible? The answer is you can.

What are the brakes

Technology does not stand still. Therefore, bicycle braking systems are constantly being improved. For the average cycling enthusiast, you need to know that there are two types of brakes: disc and rim brakes. These are two diametrically different brakes. Because of them, cyclists were divided into two camps. Some believe that there is nothing better than the good old and proven rims, while others believe that this is already an outdated technology, therefore disc brakes are much more modern and efficient than their predecessors. It should be noted that each of them is right. They have one thing in common, without which neither one nor the second will go far. These are bicycle brake pads. It is they who perform the main function. they create the friction force, which stops the vehicle. And still, disc system or rim system, brake pads for a bicycle require equal attention. This means that this element also needs to be looked after. In case of complete wear, they should be replaced immediately, since then the bike will simply stop braking. Therefore, it is very important to monitor the condition of your bike.

Bicycle brake pads: disc brakes

This type of brake is also called rotary. This is because a special disc (rotor) is used for braking, not a rim. It rotates with the wheel. The main role here is played by the caliper, which clamps the rotor with its pads. This is the whole point of disc brakes.

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How to extend the life of your brake pads

As a rule, we brake with one brake. Some people advise to occasionally change the pads from the front to the rear and vice versa. So they wear off more or less evenly.

You also need to check that the system is perfectly tuned (this applies to any type of brake). It happens that the setting flies, and some block clamps the rim all the time. So you need to pay attention to this right away. Not only does this greatly impede movement, but such a ride simply “eats” the pads. This can be the case with a disk system. The problem is solved in a simple way. with high-quality tuning of all brakes.

How To Check Brake Pad Wear | Mountain Bike Maintenance

Replacing brake pads on a bicycle

The pads on the rim brakes are also fairly easy to change. To do this, unscrew the block with a hexagon and replace it with a new one. Only after installation is it necessary to adjust the brakes and make sure that everything is evenly installed.