# What affects the diameter of a bicycle wheel

## Effect of wheel size on bike speed

There is a direct relationship between the speed and the diameter of the wheel.

From a physical point of view, the larger the wheel size, the more distance you can drive:

• Let’s say if a bike is 29 inches, then it will be much faster and more practical than a 20 inch.

However, this dependence gives the opposite result in another way. The smaller the wheel diameter, the faster you pick up speed. This is the main advantage of children’s bicycles, which, with an equal load, can accelerate to the same distance as an adult on a road bike.

However, keeping the speed will be more difficult, you will need to constantly pedal. On 26-29 inch models, the distance is covered faster, acceleration will be slow, but the speed remains longer.

## What is the best bicycle wheel size??

In the spring-summer period, parents begin to think about purchasing a bicycle for their child. And it is at this moment that mistakes are made in the search for the right purchase. In the choice, first of all, you should not rely on the appearance of the product, as this is deceptive.

Before buying, you need to know that a properly selected bike affects the human body and its further condition.

### 27.5-inch wheels

• Rim diameter: 622.
• For teenagers and adults with a height of 165 cm.
• Weighing up to 95 kg.
• Models are equipped with a low frame and the ability to select speeds.

### 20-inch wheels

• Rim diameter: 406.
• Children’s bike for height from 120 to 140 cm.
• Weight up to 40 kg.
• Folding mechanisms are suitable for the initial stage in riding training.
• A good option for children from 5 to 9-10 years old who have only recently driven.

## How to determine the diameter of a bicycle wheel

From time to time the question arises: “What is the diameter of the wheels of the bicycle?”

Most often, it pops up in case a tire has broken through or new rubber is needed on the wheel of an old bicycle. And to the seller’s question “What wheel does your bike have?” only one answer comes to mind: “round”.

First of all, you need to decide on the concept of wheel diameter.

For most ordinary people, this is the diameter of the wheel along the outer (outer) border of the tire.

But there is also the concept of the landing size of the rim. this is the diameter of the rim itself or the tire along the inner border.

For the sake of brevity, here is a figure with an explanation of what is measured in each labeling system. Therefore, it is important to understand what we are measuring and what we want to find.

## So, the methods for determining the diameter of a bicycle wheel in inches and millimeters:

• The simplest and most reliable. An old tire installed on a bicycle should have its diameter in inches or millimeters written.

When choosing a new rubber, be guided by it. If there is no tire with exactly the same marking, look at the interchangeability table and select the correct size in another marking.

If you need a new tire a little wider or narrower. check the tire and rim width chart.

If in doubt, talk to the seller. He will tell you if it is suitable for you, both in terms of size and in terms of tread, driving style and what roads you want to ride.

• See if the rim size is written on it. Sometimes manufacturers write the size in the ETRTO system in mm: landing diameter and width. Depending on this, the size of the tire is selected. What dimensions in inches are suitable for your rim size in mm can be found in this table.
• If nothing is written on the rim and, most importantly, the tire, then you will have to calculate its diameter “manually”.
• This can be done by measuring the radius and multiplying it by two.

Only you need to measure strictly from the center of the sleeve, and not from its edges. When measuring, the bicycle should stand upright, and the tape measure, putting one end to the ground, keep the same strictly vertically, and not along the spokes of the wheel. Only such a measurement will give the correct value.

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In the same way, you can immediately measure the diameter of the wheel itself. The main thing is to accurately determine its upper cut. To do this, you can take a level and attach it to the top of the tire, and, holding it strictly horizontally, determine the desired size using a tape measure.

After that, we translate it from mm to inches. To do this, divide it by 25.4 (1 inch = 25.4 mm) and calculate the size in inches. The result can be rounded to standard inch wheel sizes.

For example, if your measurements are 720 mm, divide by 25.4 to get 28.346 inches. So, most likely, the real wheel size, taking into account the accuracy of calculations, is 28 “.

In principle, the rim diameter can be measured in the same way.

Just pay attention to the difference between what is measured with a tape measure on the outside and the landing size of the rim.

For those who are not looking for easy ways in life, you can calculate the diameter of a wheel through its circumference. How to calculate the circumference of a bicycle wheel is described on our website in a separate article (Second method).

And knowing it, it is easy to calculate the diameter. To do this, the circumference in millimeters must be divided by the number “Pi” (3.14). Once you get the diameter in mm, divide it by 25.4 to get the diameter in inches. Similar to the previous paragraph, the result will have to be rounded to the nearest whole number in inches. The more accurate all measurements are, the more accurate the result and less rounding.

## Cross-country capacity of the bike from the size of the wheel

Two things affect the flotation of a bicycle:

### A bicycle with tires 68cm in diameter travels 7.2 km. How many revolutions do the wheels make?

• Profile;
• Tire width that must not be less than 2 inches.

The profile with a deep, sculpted base will allow the cyclist to navigate any rough terrain. In this case, the 24 “model will be much more maneuverable and more comfortable on rocky and sandy soil than the 29” model.

The dependence of the size of the wheel affects the permeability, therefore, to save energy on difficult territory, models with a small wheel diameter are chosen.

It turns out that before buying, you need to define a couple more criteria:

• What is the transport for;
• How often will it be used on stony and sticky soil.

You can determine the size of the bicycle frame according to the following principle: the distance from the tube under the seat to the carriage assembly is measured. Depending on the change in the pipe, the rest of the parameters will change proportionally.

This distance can be converted to inches to determine the size of the bike you need. On average, 2.5 centimeters is equal to one inch. This calculation will give the size of the frame.

When choosing models for personal parameters, it should be borne in mind that models from 27 inches are suitable for a tall and thin physique, and models from 27 inches are suitable for a fuller and lower one. up to 26 inches inclusive.

Such a selection will allow the cyclist to feel better grip on the road, and it will be possible to maneuver vehicles in a dangerous situation. Taking into account the riding style and sports fitness of the cyclist is a good choice.

## The relationship between wheel size and rider height

To avoid an unsuccessful purchase, it is better to immediately decide on the type of bike: city, mountain or walking. Each model can be matched to weight, height and management skills, so more time needs to be spent analyzing the right products.

For children, it is impossible to purchase transport “for growth” with a large frame diameter, this can adversely affect the child’s posture.

Choosing the right bike depends on the quality of the product, the price and the need for the item. But the main criterion among these is the choice of wheels for a person’s height.

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Correctly selected options will not put stress on the back and knee joints, they will correctly distribute the cyclist’s weight.

Also, the bike must be selected for individual control capabilities ^

• For a growing body up to 165 cm, it is better to choose the option with a shock-absorbing seat tube, which will not allow the seats to be completely lowered into the frame. This feature is common with mountain bikes;
• For tall cyclists, models from 27 inches are good options, which will eliminate overloading on the arms and back;
• For tall people, the 29-inch version with high speed capabilities is suitable. Models are suitable for fast long distance driving. No stress on the spine and pedal movement is much easier than on 27 and 28 inch models.

Selection of bike type by height:

• Height 190 cm (and more). road 50-52, road 46-48, mountain 41-44.
• Height 170 cm. road bikes 53-55, road bikes 50-52 and mountain bikes 44-46.

When choosing a bicycle for children, their foot should reach the ground completely. The knee should be free of bend and discomfort when lowering the pedal. When riding a child, the knees should not touch the handlebars and the down tube of the bike, so it is better to pick up transport together with the future cyclist.

## Wheel size comparison

In wheels, a lot depends on the diameter: roll-forward, wheel grip and ride safety. As the diameter increases, the quality of the rim increases and so much the better for the cyclist.

## What is the best bicycle wheel size??

In the spring-summer period, parents begin to think about purchasing a bicycle for their child. And it is at this moment that mistakes are made in the search for the right purchase. In the choice, first of all, you should not rely on the appearance of the product, as this is deceptive.

Before buying, you need to know that a properly selected bike affects the human body and its further condition.

## Effect of wheel size on bike speed

There is a direct relationship between the speed and the diameter of the wheel.

From a physical point of view, the larger the wheel size, the more distance you can drive:

• Let’s say if a bike is 29 inches, then it will be much faster and more practical than a 20 inch.

However, this dependence is also counterproductive in another way. The smaller the wheel diameter, the faster you pick up speed. This is the main advantage of children’s bicycles, which, with an equal load, can accelerate to the same distance as an adult on a road bike.

### 29-inch wheels

• Rim diameter: 622
• Wheels for tall people (180) with a wide rim and maximum grip.
• Load up to 105 kg.
• Ideal for urban wet asphalt and uneven gravel mountain roads.

### 24-inch wheels

• Rim diameter: 507.
• For adults and adolescents from 140 to 170 cm tall and weighing up to 70 kg.
• There are models with adjustable handlebars, seats and the ability to fold the bike.
• Models are suitable for city walks and road trips.

### 27.5-inch wheels

• Rim diameter: 622.
• For teenagers and adults with a height of 165 cm.
• Weighing up to 95 kg.
• Models are equipped with a low frame and the ability to select speeds.

## Bicycle wheel labeling table

 Wheel diameter (inch), unit Rim diameter (mm) Who are they suitable for? 20 (XS) 406 Child under 10 years old 24 (S) 507 Teenager under 17 26 (M) 622 Adults from 20 years old 27.5 (L) 622 Universal, for road trips 29 (XL) 622 Versatile, for mountain sports and city walks

## Dimensions of bicycle wheels and how to correctly measure the diameter of bicycle wheels for your height

If you decide to upgrade your two-wheeled vehicle or just change wheels, a logical question arises. which wheel to choose? Regardless of whether you want to buy a wheel the same size as yours, or give preference to something new, you need to be able to determine the diameter of the wheel. And, of course, you need to know what this indicator affects and why wheels of a larger diameter are more suitable for some people, and smaller ones for others.

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## The relationship between height and diameter

It is wrong to think that wheel size only affects the driving behavior of your two-wheeled vehicle. Growth is also very important here. Consider in what features this is manifested:

It is worth noting that if you are guided by height when choosing a bike and its parts, then you should observe not only the size of the wheel, but also the size of the bike frame, and in some cases, use the stem in addition to create the most comfortable driving conditions Some experts recommend taking into account, in addition to growth, the length of the legs, because it is they who get tired the most during the movement and need careful care.

## Relationship between wheel diameter and driving characteristics

Consider some options for how the size of a bicycle wheel can affect driving.

• The larger the wheel of the bicycle, the more effort and energy it takes to spin it. Therefore, you will have to train your endurance and pump up your legs. But at the same time, the achieved rotational speed will be much higher and better than in the case of a lower.
• Large wheels are easier to use on smooth and level roads. A 29-inch size would work well here. For mountain bikes with frequent stops, go for smaller rims. for example, 26.
• As for the width of the tire, here the passability on difficult areas. for example, stones or rocks. depends on its width. If you choose wheels for just such a case, then give preference to small models with a minimum width of 2 inches.
 Rim diameter in inches Rim diameter in mm Matching bikes 20 406 Kids models, BMX 24 507 Old Soviet bikes like Salyut or Altair, teenage bicycles, bicycles for extreme sports 26 559 The most common size option often used by standard mountain bikes or city bikes 27 622 Road bikes 28 622 Old Soviet model bicycles such as Ukraine or folding Aist, as well as hybrid and road bicycles 29 622 One of the latest developments in the field of cycling. Can be used for both advanced mountain bike models and everyday riding

## Which option is better to choose?

If there is no controversy about the smallest wheel sizes, then it really boils about rims with a diameter of 26 and 29 inches. This is one of the most popular sizes, but in fact there are quite visible differences between them, knowing which you can easily choose the option for your bike and body.

• Bicycles with 29-inch tires pick up the required speed quite easily, handle well, just overcome obstacles, handle turns freely. But in comparison with a diameter of 26 inches, such a bicycle on average picks up speed only with a large expenditure of energy, so it takes more time to circle.
• 26-inch wheels are more agile in action, pick up speed much faster and stop easier. But as for inertia, here the rim with a diameter of 29 inches takes the palm.
• If you are looking for the option to tackle various bumps, then 29-inch wheels are your option. Since they have a large area of ​​contact with the surface, you will overcome bumps without even noticing them. Also, driving on a steep incline will give you much less inconvenience if the rim size is larger. Accordingly, on a bicycle with a wheel diameter of 26 inches, you will need to expend more energy and strength to overcome obstacles.