Table of Contents

## 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 chart:

Wheel, inches / mm | Rim, mm | Bicycle |

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 subtract the height of the tire, multiplied by two. Standard rim sizes are shown in the second column.

Bicycle wheel measurement systems:

- 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 the 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 |

fourteen | 98. 104 | 3. 5 |

14, 16 | 104. 110 | 4. 5 |

16, 18 | 110. 116 | 5. 6 |

twenty | 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.

## How to measure the diameter of a bicycle wheel

### How To Lift Your Rear Wheel | Mountain Bike Skills

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.

## 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 the 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 on it we select another tire.

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 dyed mowing 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.

## 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.

## How to properly tighten the spokes on a bicycle?

In this article, you can learn how to properly tighten the spokes on a bicycle, what you need for this. How to check the correct tension of the spokes, wheel runout (vertical horizontal). It will be easy for you to figure out how to tighten the spokes on a bicycle.

- Spoke wrench
- Special tool for centering the wheel
- Wrenches for removing a wheel from a bicycle
- Screwdriver

Remove the wheel from the bike and install it in the wheel centering device. If there is no device, then you can leave it on the bike, while the latter must be turned upside down with the wheels. Determine which knitting needles are poorly tensioned. To do this, we swing the knitting needle to the sides with our fingers. The vibration amplitude should be about 1-2 mm. We mark the problem needles with a small or small piece of electrical tape. We tighten them until the amplitude is close to normal. Inevitably, a “figure eight” will appear, a horizontal beating that should be eliminated.

Determine the amplitude of the horizontal and then vertical beats of the rim (figure eight and ellipse). Only after determining all these parameters do we already know almost everything about how to properly tighten the spokes on a bicycle. It remains only to eliminate all these problems. We eliminate the “eight”. If there is a wheel centering device, great. Those who do not have this device can mark its boundaries with the help of a crayon. It is enough to support the crayon on the bicycle frame at the level of the wheel disc; when the latter is twisted, it is gradually moved forward until the greatest beat is noted.

We start pulling up the knitting needles. If, for example, the hump is at the level of four spokes to the right, then we pull the two spokes going to the left flange by half a turn, and release the remaining two spokes going to the right flange by half a turn. This will move the rim to the left. If three knitting needles hit the level of the hump, one to the left and two to the right flange, then pull the first one half a turn, and release the two right ones a quarter turn. So, we have already figured out how to tighten the spokes on a bicycle and not allow the “eight” to appear. Let’s move on to straighten the ellipse.

In the same way as when determining the horizontal beating, we also determine the vertical beating. Either with the help of a device, or with the help of a chalk, only you need to bring the chalk closer to the center of the wheel. We tighten the most distant section of the ellipse by pulling the knitting needles that fit it. If the problem area contains three knitting needles, pull up the middle one by half a turn, and the two on the edges by a quarter turn. If the section contains a paired number of knitting needles, then pull everything up by half a turn. So the wheel is already round. Check again if all spokes are tight enough. If so, great. If not, then it is necessary to tighten all the spokes by the same amount and then restore the concentricity of the wheel.

## Sizes of bicycles and tires

We measured the rim, how to **find** out the diameter of a bicycle wheel. we found out, you can get acquainted with the standard sizes of your tires, as well as **find** out what type of **bike** they are mounted on.

Choose the size of the rubber for your two-wheeled friend, not for beauty and personal sympathy, but based on the environment and road surface.

A few words about the exact size when buying a new rubber, you should know the rim rim diameter. You will need it when buying new

wheels.

## Circle

The second required dimension is the circle. There are several surefire ways to measure the circumference of a bicycle’s rim:

- We take a non-elastic thread, wrap it around the top of the rubber. We lay it out exactly on the surface, take a ruler and op!. we get the length of our tire.
- From the course of school mathematics according to the formula: circumference = πr 2.where π is a constant number 3.14, and r is the radius (the method of measurement is above).
- With a drop of paint. Place a dot on the tread, then run your bike on a level mowing line and on a smooth (eg asphalt) surface. The point will be printed twice, the distance between them will be the circumference.

## How does the wheel size of a motorcycle affect its performance?

One of the most important properties of a motorcycle. its dynamics. depends on many parameters, among **which** is the amount of torque supplied to the rear wheel. This characteristic must exceed the moment of resistance, which directly depends on the dimensions and characteristics of the wheel. If the wheel is too large, then the motorcycle will experience a sharp decrease in dynamic qualities, but the speed will be high. If the wheel is too small, then not only the dynamics and controllability decreases, but also the cross-country ability, since there will be constant wheel slip and wheel failure in soft soils such as sand and mud. Therefore, in order to achieve good motorcycle performance, it is necessary to select the correct wheel sizes and tire specifications.

## Wheel markings

We would like to add a few words about markings on cameras and tires. They are applied according to the classical system of standards and according to ISO (international).

According to the classic marking, the dimensions are applied as follows: parameter D, then the width of the profile (all in inches). For cameras, the dimensions are set according to the same principle, corrected for height.

In the ISO international system of standards, dimensions are given in millimeters and are indicated vice versa. First, the height of the wheel is prescribed, and then the circumference of the landing rim. Follow the manufacturer’s recommendations when choosing tires. Correctly selected ones will serve you much longer. For example, tall ones are quickly erased on the sides, and narrow ones are often pierced.

This is how, in different ways, you can determine the diameter of a bicycle wheel, measure everything and calculate with the help of ingenuity. We hope that you will only measure your wheels for pleasant reasons.

## Standard measurement method

To determine the diameter, you first need to know the radius of the wheel. Knowing the latter, you can calculate the diameter. According to the mathematical formula, the diameter of a circle is equal to two radii: D = 2 r.

## Wheel size and dimensions

The wheel traditionally consists of a hub, rim, spokes, tire and tube. The sizes of all these components are interrelated. The overall dimensions of the wheel depend not only on the diameter of the rim, but also on the width of the tire. **Wheels** with wide tires can also be used in winter, as you can make them studded. Also, the width of the tire has a positive effect on permeability, but reduces the speed. Many sports bikes have a very narrow tire for maximum highway speed with a 28 ” wheel.

The most common wheel sizes in Russia are 26, 24 and 20 inches. Often bicycles with 20-inch wheels are foldable, which is essential for storing it in small spaces.

## Measuring the size of a bicycle wheel

To **find** out the parameters of the bicycle wheels, you need to measure the diameter of the seat. This will require a thin, soft wire or steel tape that is placed on the first shoulder, which serves as a seat for the tire, and wrapped around its outer surface until a fully closed ring is formed. Then the tape is carefully removed from the rim, stretched into a straight line and measured with a tape measure its total length. The resulting figure is divided by 3.14. this is the diameter of the wheel.

The inner tire size can also be determined by subtracting twice the tire cross-sectional value from the outer diameter.

Another very accurate measurement method is to plot a straight line on a level, level surface. On this mowing line, you need to drive one turn of the wheel, pressing on the steering wheel. at the same time, a mark must be made on the tire in advance (if you wish, you can drive not one, but several turns). Then you just need to measure with a tape measure the segment that the wheel has traveled. To get the most accurate result, the ride can be repeated several times and the average is calculated, **which** is the size of the bicycle wheel.

### ISO measurement

The accepted unit of measurement in the ISO system is millimeters, respectively, if you measured in centimeters, you just need to multiply your result by ten.

The measurement process takes place exactly as in the first case, but the radius is measured from the center of the axis to the outer edge of the rim, the diameter is found by multiplying by two.

To measure the width of the wheel, the same steps are taken as in the first method, and it should be borne in mind that if the width of the original tire is only slightly different from the one you are going to purchase, then you will not have any problems when replacing.

For marking bicycle wheels in the ISO system, it is not customary to put the width of the wheel, and then its diameter, respectively, marking 53.3 x700 indicates that we have a tire with a width of 53.3 mm and a diameter of 700 mm.

### Standard method

Initially, it is necessary to install the bike vertically in such a way as to exclude its accidental fall, it is best to fix the bike in an upright position.

Then, using a tape measure, determine the distance from the center of the wheel axis to the floor. This value must be divided by 2.54 and the result is the wheel radius in inches. The diameter is equal to two radii, which means that the resulting figure will need to be multiplied by two, and do not forget about rounding. To understand the wheel diameter of 40 cm, how many will be in inches, you need to divide 40 by 2.54 and you get the required value of 16 inches.

Further, to obtain complete information about the tire or tube, you need to measure the width of the wheel using the same tape measure.

According to modern standards, bicycle tires are labeled in the following order: the first number indicates the diameter of the wheel, followed by the width of the wheel. The marking, expressed in numbers 26×1.75, indicates that the tires for this **bike** have a diameter of 66.04 cm and a tire width of 4.445 cm.

## Bicycle wheel rim 28 and 29 inches

The legendary bicycles “Ukraine” were famous for such rim sizes (28 inches. 655 mm). By the way, they still continue to be released with them.

In addition to this model, bicycle rims (28 inches) are usually fitted on models designed for riders up to 180 cm. Typically, these wheels are found on hybrid and road bikes, as well as city bikes.

In recent years, a variation of the aforementioned size has emerged, which is conventionally called “29”. In reality, the rim size is similar to the 28th. 655 mm. The only difference is in the size of the tires. Despite the fact that there is no fundamental difference between them, the 29th size is actively positioned as the most modern, adapted to the needs of cyclists with a height of more than 180 cm.

## Circle

The second required dimension is the circle. There are several surefire ways to measure the circumference of a bicycle’s rim:

- We take a non-elastic thread, wrap it around the top of the rubber. We lay it out exactly on the surface, take a ruler and op!. we get the length of our tire.
- From the course of school mathematics according to the formula: circumference = πr 2.where π is a constant number 3.14, and r is the radius (the method of measurement is above).
- With a drop of paint. Place a dot on the tread, then run your bike on a level mowing line and on a smooth (eg asphalt) surface. The point will be printed twice, the distance between them will be the circumference.

## Size classification

The wheel diameter is 20 inches for kids, folding and BMX bikes, and 24 inches for freeride and similar extreme sports. Mountain bikes, city bikes and touring bikes have a wheel size of 26 inches, while road types have a wheel size of 27 inches. Road and hybrid varieties, as well as traditional Soviet models, are 28 inches in diameter. The new standard for mountain **bike wheels** that is gaining popularity is 29 inches.

The most common size for a modern bicycle wheel is 26 inches.

Tires with diameters ranging from 27 to 29 inches fit on rims that measure 622 millimeters. The change in the total diameter of a wheel is solely due to the thickness of the bicycle tires. To determine it, you need to look at the size of the tires that were previously installed on the **bike**. Typically, the size of bicycle tires is located on the sidewalls (as in car tires). Its size and the rim diameter of the wheel should correspond to each other as much as possible.

## Measuring the size of a bicycle wheel

To **find** out the parameters of the bicycle wheels, you need to measure the diameter of the seat. This will require a thin, soft wire or steel tape that is placed on the first shoulder, which serves as a seat for the tire, and wrapped around its outer surface until a fully closed ring is formed. Then the tape is carefully removed from the rim, stretched into a straight line and measured with a tape measure its total length. The resulting figure is divided by 3.14. this is the diameter of the wheel.

The inner tire size can also be determined by subtracting twice the tire cross-sectional value from the outer diameter.

Another very accurate measurement method is to plot a straight line on a level, level surface. On this mowing line, you need to drive one turn of the wheel, pressing on the steering wheel. at the same time, a mark must be made on the tire in advance (if you wish, you can drive not one, but several turns). Then you just need to measure with a tape measure the segment that the wheel has traveled. To get the most accurate result, the ride can be repeated several times and the average is calculated, **which** is the size of the bicycle wheel.

### Rim brakes. braking occurs due to the compression of the brake pads directly on the rim disc.

Advantage: the so-called “brake sleeve” is as close as possible to the diameter of the wheel itself, **which** means that the effort on the spokes and the hub is minimal. Relative ease of maintenance. Cons: inability to use with a curved rim, deterioration in efficiency when the rim is wet.

There are varieties in the rim brake family:

Good old rim brake technology, mostly found on road bikes. With each mountain, this technology is gradually becoming a thing of the past.

Endangered species of brakes. Although this technology had a take-off period, today they are only installed, as a rule, on very cheap bicycles or children’s bicycles. From the pros. space, of the shortcomings. low efficiency.

Hydraulic rim brakes:

Everything is very technological, but complicated. There are no levers with bindings here. The brake cylinder is located on the steering wheel, the hydraulic tube transmits the force to the pads, which are extended to the rim perpendicular to the frame. Quite an expensive pleasure, significant weight gain and difficulty in repairing on the go make this system rather narrowly focused, usually in Trial. However, it should be noted that the braking efficiency is quite high.

The most popular brake system. The principle of operation is the same as for cantilever brakes, however, a number of modifications in the design make them much more effective. The main difference is the modified levers and the liner to the levers themselves, the possibility of parallel placement of the pads, which gives synchronous wear of the pads and an increase in braking force.

Low weight, easy maintenance, good system modulation.

### Disc brakes

in recent years, they have become more and more popular, they are equipped even for entry-level bicycles. They consist of a rotor fixed to a bushing, a support and a hydraulic supply tube or a supply cable.

Advantages: durable with proper care, do not require constant adjustments, effective in all weather conditions. Disadvantages: additional weight, less brake sleeve, **which** means more effort on the spokes and bushing, more complex mechanism, **which** complicates the “field” repair.

Just like rim brakes, disc brakes have a number of their own modifications:

Mechanical disc brakes.

### How to check your wheel rims for wear

The system is quite simple, although you cannot say so from the outside. As with rim brakes, braking force is transmitted to the caliper via a cable. Their main disadvantages are also hidden here: the possibility of stretching the cable, breaking the shirt will lead to poor cable travel, however, the affordable price and simplicity of design, in contrast to the hydraulic brake system, makes them an excellent choice for both beginner cyclists and experienced cyclists.

Hydraulic disc brakes.

The principle is already familiar to us. When you press the brake lever, as in hydraulic rim brakes, the brake fluid, with the most accurate coefficient, transfers forces to the brake cylinder through the high-pressure hose. High efficiency robotic system, excellent modulation. But there are also disadvantages: The weight of the system, the complexity of the device, often requires a special tool during repair, even on modern systems there is a possibility of system leakage. Quite an expensive allowance. Despite all the potential problems, this is a great choice for mountain biking.

### Everything You Need To Know About MTB Wheels | Mountain Bike Jargon Buster

## Types of bicycle brakes, their variety and properties.

### Drum brakes

The principle of operation is almost the same as with an automotive drum brake system. The brake pads are located directly inside the hub, pressing against the rotating part slows down the rotation of the wheel.

Advantages: Easy to maintain, not susceptible to dust and dirt, as the mechanism itself is closed. The durability of the mechanism. Disadvantages: the weight of the structure, almost impossible to repair in field conditions, does not have sufficient strength of the mechanism for use in extreme conditions, such as trial, downhill, cross-country. However, very often such a braking system is used on road and recreational bicycles. This system is very convenient when walking.

## Bicycle Wheel Selection. Size Chart

The wheel is the most important part of the bike. When choosing it, you should rely on two parameters: weight and size. And if the weight is easy to determine. what is easier is better, then when choosing a size, the cyclist may be puzzled, because this characteristic directly depends on the scope of the bike. To simplify this task, experts have compiled tables with bicycle wheel sizes and implemented a traditional marking system. We will tell about them.

## Quantities, Units and Conventional Markings

When determining the parameters of the wheel, the following values are measured:

- Outer wheel diameter;
- Rim and tire widths.

It is customary to use inches as the unit of measurement. However, albeit rarely, but you can still **find** markings in millimeters. The most common sizes: 20 ″, 24 ″, 26 ″, 27 ″, 27.5 ″, 28 ″ and 29 ″. these are the numbers traditionally indicated on the rims and indicate the diameter. Type marking diameter x width is indicated on the side of the rubber, for example 26×1.75.

Important: in some cases, instead of a dot, they write the sign of the fraction 26×1¾, and although this is mathematically equal to 26×1.75, such tires are not interchangeable.

It is useful to know that the rim diameter is found in only five variations: 406, 507, 559, 584 and 622 millimeters. In this case, 622 mm is intended for 27 ″, 28 ″ and 29 ″ tires. The use of rims with a smaller bore diameter is not provided for them.

## International Organization for Standardization (ISO) Marking

To eliminate confusion with parameters, a universal ISO marking system has been developed. All manufacturers use it.

This marking is based on two values:

- Tire width (dm);
- Width of the landing diameter of the landing rim (mm).

When choosing a rubber, it is necessary to pay attention to the landing diameter: it must necessarily coincide with the original parameters of the bicycle rim. So, 29-622 29-622 tire is interchangeable with 27-622 road, despite the fact that their width is different.