The same materials are required for measurements.
- Wheel Diameter The distance from the center of the wheel to the outer edge of the rim is measured. Multiplications are performed in the same way as in the first case. The difference is only in units of measurement. According to the international standard, the value of the radius is indicated in millimeters. Therefore, the resulting diameter in cm is converted to mm. 1 cm = 10 mm. For example, D = 50.8 cm, this number is multiplied by 10 and you get 508 mm.
- Wheel width Measurement is carried out in the same way as in the standard method: the tape is placed across the tread pattern. The result obtained is reduced to the accepted unit of measurement in the ISO system. to millimeters.
[attention type = yellow] Tip! Their service life will depend on the correct choice of the type of tires. When using the rubber recommended by the manufacturer (or values close to the specified), it will last longer. So narrow tires are suitable for walking on a flat road, and wide. off-road. [/ Attention]
With an inelastic cord
To do this, pull a thread, cord or cable around the bike tire. Its thickness does not matter, the main thing is that it fits snugly against the rubber. Next, you need to make a mark at the place of its contact with the initial end. Then remove the cord, spread it on the ground and use a ruler (tape measure) to measure the distance from the starting end to the marked mark.
The required value can be calculated using the formula, knowing the diameter of the tire. The diameter can be indicated on the tire itself or determined using the previously described method. The circumference of the wheel is equal to the product of its diameter by the number Pi: C = D π. Unit of measure inches.
For example, 20×3.14 = 62.8 “, where 20 is the diameter of the tire in inches, and 3.14 is the pi number (constant).
This value is no less important than the previous ones. After replacing an old or damaged bicycle tire with a new one, you need to adjust the exact operation of the instruments (speedometer, odometer, navigator). To do this, the size of the circumference of the wheel is entered into the cycling computer.
You can find out this parameter in several ways.
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.
Measurement, as in the above case, is made with a tape measure. It is placed on the tire perpendicularly and the distance from one edge to the other is measured. The tape should be held strictly horizontally (that is, across the bike tire) so that the result is as reliable as possible.
The width of a bicycle tire purchased to replace a damaged one may slightly differ from the original one (be slightly wider or slightly narrower). This fact will not affect the ability to install it.
How to measure the diameter of a bicycle wheel?
When you need to replace a punctured tire or purchase a spare tire, it is important to know the diameter of the bicycle wheel. The marking can be viewed on the currently installed bus. It is printed on the side of the tire, and indicates its diameter and width. If the numbers are erased or the inscription is not readable, you can measure the diameter of a bicycle wheel yourself using two simple methods.
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 = πr2, 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.
The smallest wheels found on bicycles are 20 inches in diameter. They are usually found on children’s or folding bikes, as well as on BMX bikes.
Choosing the diameter of the bicycle wheels
If the choice of a bicycle catches the layman by surprise, then the choice of its components takes place at a more conscious level. However, the general and understandable picture can always be violated by one component. So it was with wheels with a diameter of 27.5 inches.
A year and a half ago, the mountain bike market was divided almost equally between bikes with classic 26-inch wheels and the increasingly popular 29-inch wheels.
The main advantages of the former were their quick acceleration, low weight and good climbing. The second ones stably maintained the speed with less effort and showed excellent grip performance.
And although initially few believed in the effectiveness of the 29-inch, focusing on their shortcomings, over time they became the main trend in cycling.
The new 27.5-inch wheels are not new and have been used in less popular models before. However, their appearance at leading companies created a real explosion in demand.
This popularity can be explained quite simply. many needed an alternative between the two polar riding styles. Combining good grip with fast acceleration has created a very competitive product.
On the other hand, such a statement does not mean that the previous market leaders are futile.
What to choose and how to be sure that such a choice is justified? Naturally, the easiest option is to try all three wheels first-hand. This way is better than any theory. However, most often it is very difficult to implement, if not impossible. Then the first step of a potential consumer should be the question “What do I need from a bicycle?”.
The obvious fact is that for each specific riding style there are priorities in the choice of wheels. But even here a number of questions arise, because rarely an amateur specializes in something specific.
In this case, you need to look at the problem of choosing wheels more broadly. choosing the priorities of the bike in general.
Here the choice of a future rider does not lie between two main options, but within the framework of a whole set of criteria.
One of these criteria is weight. The issue of weight in the case of wheels is not a matter of the bike’s transportability, but primarily of speed. The difference in weight between 26 and 27.5 inch wheels ranges from 150-250 grams, while the difference between 27.5 and 29 inch wheels ranges from 350 to 400 grams.
Thus, between 26 and 29 inches, the range can be up to 700 grams, which significantly affects the speed of the bike. Weight selection is not about choosing between a relatively fast, medium and slow bike, but rather between two fast and one slow. Difference between 26 and 27.
5 inches is negligible enough not to pose a major speed issue.
The issue of overcoming obstacles on the road is also very important. In this situation, the leaders are wheels with a larger diameter, significantly beating out their smaller competitor. On the other hand, 27.
The 5-inch wheels are not far behind the 29-inch wheels, staying well ahead of the 26-inch counterparts. The issue of overcoming obstacles significantly affects the speed of the route.
The reason for this is not only the fact of losing time on the obstacle itself, but also the need for acceleration after passing it.
Acceleration and acceleration rates in mountain bikes are much less important than those in road bikes. However, if we are talking about an ascent or a high-speed section of the track, this characteristic comes to the fore. The leader in overclocking, by a rather serious margin, is the 26-inch wheels.
In addition, accelerating on 29-inch wheels will be significantly harder physically, which is quite frustrating. It is also necessary to say about the climbs in general. These elements of the track are easier to pass on 26-inch wheels. About 27.
5-inch wheels, it is worth noting that here they lose quite a lot to 26-inch wheels, sticking to the honorable middle.
One of the trump cards in conquering the bike market with 29-inch wheels was excellent grip. The same factor played into the hands of the new 27.5-inch wheels. Such indicators are provided by the factor of greater contact with the ground.
It is very difficult to consider this characteristic in numbers, since the geometry of the rubber and the type of road surface have a significant influence on this process. Obvious in terms of grip is the fact that the 26-inch wheels are lagging behind.
This trend shows the absolute failure of these wheels in certain riding styles.
Last but not least is the rider’s growth factor. This is a characteristic that has held back the proliferation of 29-inch bikes quite a bit. many felt uncomfortable on huge bikes. In this case, the 27.5-inch variant provides an alternative to the existing large-wheel format.
It is likely that even after assessing their needs according to the described criteria, the bike was not selected. In this case, you need to look at everything from a rather detached point of view. So you can summarize the entire current market to two main options: 27.5-inch and 29-inch wheels. The former have significant advantages in terms of overclocking, more maneuverable and lighter.
Such bicycles will also be very convenient for people of short stature and lovers of smooth riding. Riders who choose 29-inch wheels will have better grip and obstacle handling. In addition to the disadvantages described earlier, frame wear will be problematic, although this is compensated for by the better condition of the rubber. 26-inch wheels are more likely not a third option, but a competitor 27.
DIY Spoke Length Ruler How to Measure a Spoke
Finally, I would like to note that the wheels of the new format are still worth trying out. Fans of 26-inch wheels will definitely love the benefits the new model has to offer. Naturally, you should not rush to throw your bike into a landfill, but you should definitely think about the next one.
Useful information: current for services
- Bicycle rental in Kiev
- Cycling training
Wheels measuring 29 inches are a relatively new standard, but they have already managed to conquer the market. They are becoming more and more popular every year, as they are great for mountain bikes, as well as for walking and road bikes.
In general, the quality and comfort of riding depends not only on the size of the wheels, but also on the width of the tires and the pressure in the chambers.
Another important point is that the heavier and larger the wheels, the more difficult it is to accelerate the bike, but if you have already succeeded, then the speed will be much higher than that of a bicycle with smaller diameter wheels.
In addition, Twintiners (as 29-inch wheels are called) are much better at coping with various bumps, stones and other obstacles, which means that the cyclist will be much less fatigued from riding.
The fact is that during their lifetime, bicycle rims and tires have undergone a number of metamorphoses. over, there are at least two common marking systems: European and traditional. As a result, the actual dimensions of the wheels and tires may not match the markings indicated on them. But a detailed analysis of this issue is perhaps beyond the scope of this article.
Summing up, we can say that the diameter of the wheels with which the bicycle is equipped, of course, affects the ride quality, but not so much as to attach much importance to it. The comfort of cycling rather depends on the cyclist and his riding level, as well as on the correct gear shifting and, in general, the bike setup.
How to measure the diameter of a bicycle wheel
Universal Adult Bike Selection Chart
|Frame dimensions, inch||Height, cm||Frame size, cm||Frame size, letter code|
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Tire measurement using the ISO method
Find out if your tires are measured using the ISO system instead of the conventional method. The ISO system uses millimeters to determine the dimensions of a bicycle wheel. If you do not have a tape measure to measure a wheel in inches, just know that there are 25.4 millimeters in one inch and use a calculator to multiply the width by 25.4.
Make sure the bike is placed against a wall or on a stand. Measure in millimeters from the center of the wheel to the inner edge of the tire. Double this number to calculate the diameter. Most ISO-measured adult bicycle tires are 650 to 700 millimeters in diameter.
Measure the tire width in millimeters. Use the recommendations above for measuring the tread. Remember that tires of different widths can be used on the same bike as long as the difference is not too drastic.
How to measure a bicycle wheel
To purchase a spare tire for a bicycle, you must first determine the size of the wheel. In fact, measuring a wheel is a common procedure during bicycle maintenance.
Bicycle wheel measurements can be done in two ways, including tire and rim sizing, and both are simple to perform. Sometimes it is necessary to know the circumference of the wheel, which is also not difficult and can be done in several ways.
Measuring the tire in the usual way
Place your bike upright by leaning it against a wall or on a stand. When the bike is positioned strictly upright, it does not lean on you, and it is easier to measure its wheel. If you are measuring the wheel alone, it is better to use a metal tape measure rather than a plastic one, as this can be done with one hand.
Measure the distance in inches from the ground to the center of the wheel. This will measure the radius of the wheel or half the diameter. Multiply this length by two to calculate the tire diameter. Except for BMX models, most adult bicycle wheels are 26 to 29 inches in diameter.
Measure the distance from one side of the tread to the other. This number is the width of the tread. It can vary greatly, depending on the destination. Generally, the wider the tread, the higher the flotation, while the narrower tread is used for a smooth and fast ride.
Calculating the circumference of a bicycle wheel
Measure the circumference, or distance, along the outer edge of a bicycle wheel, in order to more accurately adjust the speedometer, odometer, GPS or bike computer. If you recently purchased a cyclometer or you need to adjust an existing one because you have installed tires with a different tread size, you need to determine the wheel circumference.
Calculating the circumference is easy by multiplying the tire diameter by pi. The circumference can be quickly determined if you already know the outer diameter of the tire. Since pi is 3.14, the circumference of a 26 “tire can be obtained by multiplying 26 by 3.14, which equals 81.64”. If you already know the tire diameter and tread width, the circumference can be found on the Internet.
Measuring the circumference with a rope. If you do not know the diameter of the wheel, you can measure the circumference by gently running a string around the outer edge of the tire. Mark or cut the thread where it reaches the starting point and measure its length to determine the tire circumference.
Why do we need bicycle size tables?
The nominal dimensions given in the technical documentation are not always accurate. The manufacturer may indicate, for example, the height of the seat tube or the distance from the center of the carriage to the point where the extension of the upper tube and the steering column meet. Each manufacturer can specify some of their measurements. Despite the fact that they will all be correct in their own way, the measurement technique can introduce some ambiguity and confuse the buyer. Therefore, buying a bicycle “by eye” is dangerous. you need to test it, sit on it, feel.
To avoid confusion, the developers have created certain tables that can somewhat facilitate the choice of a vehicle.
I already had an article on how to choose the right bike size, in which I tried to convey the main idea: the size of the frame is not what they write on it in the form of numbers like 19 ″, 58cm or the letters XL.
These designations only indicate the height of the seat tube. not too valuable information given the variety of geometries on modern bicycles.
Therefore, there is only one answer to the question “what size of frame to choose with the growth of XXX”. look at the length, not the height.
When choosing a bike via the Internet, when there is no way to ride it, open the manufacturer’s website and look for the Geometry table for the model you need. You need ETT value.
The ETT (estimated top tube) is an imaginary line that runs from the top of the head tube to the seat post. Since it is sometimes confused, I want to emphasize that this is not the physical length of the top tube, but an imaginary mowing line that can only be run on a assembled bike.
I have received quite a few questions from aspiring cyclists on how to find out which ETT value is right for them. The best way is without a doubt your own experience.
If you are able to ride different bikes, the correct frame length is instinctively felt. In principle, we all have friends with whom we can agree on an hour test drive, this is enough to understand.
However, there is also a scientific way. this is calculations using various online ETT calculators found on the Internet. I dislike these services a little, because they often give different values, and they do not always correspond to real practice.
Nevertheless, one such calculator quite impressed me, try it. This service is not for freeloaders: it takes a lot of work to find out the sizes you need. One cannot cope, you need an assistant with a building level and a tape measure.
But he counts quite accurately, I got my favorite ETT 630 mm-650 mm for a mountain bike and
600 mm for road bike. The main thing is the exact measurement of your body, if you enter the numbers by eye, the calculator gives absolutely wild values.
However, I can’t vouch for this service, because my friend said that he chose a shorter length for him than he was used to. This is not surprising, it is probably impossible to take into account all the options for the structure of the human body.
Perhaps my readers use some other calculators that have proven their accuracy, please post links in the Комментарии и мнения владельцев.
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General recommendations when choosing an iron horse
The key to choosing a frame configuration is the intended use of the bike. A walking bike is suitable for riding in parks with good road surfaces. In this case, the size will not play a special role, because the loads will rarely occur. Here you can leave extra space. choose a handlebar a little higher, and a saddle a little lower.
Racing and road bikes are the exact opposite of a touring bike. The athlete needs a low handlebar. This provides quick pedaling relief. For this type of vehicle, the main selection criterion is the size of road bikes. The size of the frame in this case must fully correspond to the height of the rider.
For touring (or cross-country) models, general guidelines are appropriate. It’s a versatile bike style.
Choosing a bike for a child
There are some fundamental differences here. First, there is no need to accustom a child to an adult bicycle or buy it for growth. This is fraught with injury. The child will not be able to reach the pedals freely. Forced to constantly stretch, it can fall or slide off the seat and hit the frame. Also, he does not have enough strength to press the brakes, since their handles are large. And they are pressed too tight.
Secondly, it is better to select children’s bicycles not only by the size of the frame, but also by the diameter of the wheel. After all, the distance to the frame is adjusted by the height of the saddle and handlebars. The table “Bicycle size for a child” will help you to navigate this.
From the history of determining a suitable height
To determine the optimal vehicle size, several parameters must be considered. In the history of Soviet bicycles, everything was much simpler. at that time only road and road types of bicycles were produced. Frame geometry has always been standard. The positions of the saddle and handlebars could be adjusted as needed. The main Accent was made to the height of the horizontal pipe, since it could not be adjusted or changed. Therefore, only this size of the bicycle frame was the main parameter when choosing a vehicle.
The size of the bike frame is understood as the size. The table usually reflects this parameter in inches. Although there are letter and centimeter designations. What do you need to correctly determine the height of the frame? The most important thing is to know your height. Only exactly, and not with a spread of 10 cm.Otherwise, the table of sizes of bicycles for growth will help to orientate.
How to measure your bike frame size
When choosing an “iron horse”, many are guided by anything but the size of a bicycle. Someone considers the size of the wheels, the comfort of the saddle or the softness of the movement to be the most important parameters. For some, only the material, design and color of the vehicle are important. However, the most important selection criterion should be the unconditional rider comfort, and this can only be achieved by the presence of key elements.