The most important parameter that makes sensePay attention when choosing this vehicle - it is the size of the bike (that is, the size of the frame). Not so important material, model and appearance, as the comfort and appropriate size of the iron horse. Only in this case it will be convenient to drive.
History of sizes
To choose the optimal bike size,It is necessary to take into account a number of parameters. Previously, everything was much easier. In Soviet times, there were only road and road bikes. The frame had a standard geometry, and the upper tube was always located strictly horizontally. Therefore, it was easy to find the optimum height. If necessary, it was always possible to additionally adjust the position of the steering wheel and seat. The selection was carried out on a horizontal pipe, since it was the only parameter that could not be adjusted. In other words, only the size of the bicycle frame was used as the most important parameter. Everything else was driven by growth.
В настоящее время ассортимент велосипедов has expanded. There were frames of various geometries, with many types of bicycles, the seat tube is located diagonally. Very often, one has to deal with a wheel that is not adjustable in height, etc. All this complicates the choice of a suitable model. And besides this, manufacturers consider height differently and use different length systems. Now it is used not only the size of the bike frame, but also the size of the wheel, the distance between the wheel and the seat, and other parameters. However, the height of the seat tube is still one of the leading factors. When jumping from a bike too high, you can hit the groin and even hurt yourself. When the frame is too low, skating becomes uncomfortable, you have to raise your legs above the head, as a result, the load is distributed incorrectly, which is also harmful to health.
The notation used in the formulas
The calculation formulas used are rather crude.In addition, there are a great many. They can vary not only from model to model (mountain, road, sport), but also from manufacturer to manufacturer. However, the formulas to a greater extent take into account the peculiarities of the bicycle, and not the person. And yet in the shops they often resort precisely to the calculated method of selection.
On a bicycle, the details are indicated as follows:
- C is the length of the saddle tube.
- SS is the horizontal distance between the saddle and the steering wheel.
- SIZE (C-C) (the center of the pedal carriage - the middle of the upper tube).
- SIZE * (C-T) (the center of the carriage is the upper edge of the seat tube). This is so-called. frame height.
From a person, only one parameter is required: height of the perineum - VP. It is measured on the inside of the leg, from heel to groin. Also in some cases the height of a person is used.
How to determine a suitable bike size: formula
When selecting, it is necessary to specify the method for measuring frame height: C-C (center-center) or C-T (center-top). Formulas in this case will be different.
The size of a road bike is calculated using the following formulas:
- SIZE (C-C) = 0.65 x VP.
- SIZE * (CT) = 0.67 x VP.
Mountain bike size is calculated differently:
- SIZE * (CT) = 0.67 x VP - 10 cm.
- SIZE (C-C) = 0.67 x VP - 12 cm.
For mountain bikes, the distance from the steering wheel to the saddle becomes paramount, since the former is often impossible to adjust.
Fitting method
To do this, stand on level ground, holdingseat tube between the legs. It is necessary to measure the distance between the groin and the frame. For a road bike, this parameter is optimal with indicators of 25–75 mm, and for mountain bikes - 100–200 mm, in some cases up to 5 cm.
table of correspondence
However, not all stores have the opportunitytry on a bicycle. Therefore, they often resort to different correspondence tables. For different models, the parameters may vary. Usually bike sizes are indicated in inches (figures), less often - in centimeters. Lettering may also be used. But the most generalized experience would be:
Frame size in inches | Letter marking | Person's height in cm |
13-14 | KCC | Up to 150 |
14-16 | FROM | 150-160 |
16-18 | M | 160-170 |
18-20 | L | 170-180 |
20-22 | HL | 180-190 |
22-24 | XXL | 185 and more |
Of course, the proportions are taken averaged.Accuracy to millimeter is not expected. However, approximately orient in the sea of goods, it will help. Knowing at least an approximate ratio of body length and frame height will significantly narrow the search range.
Choosing a bike size depending on the type of riding
The frame height will differ not only fromdestination bike, but also on driving style, planned operating conditions. And this convenience of one or another type of riding is determined by the size of a bicycle. The table will help determine the choice. So, for unhurried city walks, you can buy a two-wheeled friend at the upper boundary. For example, with a height of 160 cm, an 18-inch bike will be quite comfortable for urban environments. And for aggressive riding, mountain trails and other difficult elements it is better to use a more compact iron horse with a frame of 16 inches or less.
Other parameters of size: wheel size
Often manufacturers indicate the diameter of the wheel.Depending on this value, all bikes can be divided into children and adults. The first category includes wheels with a diameter of 12 to 24 inches. 20-24 inches are already considered teenage. By the way, adults of low stature may well ride on such models, since the iron horse with a large wheel proportionally increases the frame, the distance to the steering wheel and all other parameters.
26 and 29 inches are common sizes for adult mountain bikes. The number 28 is often found on models designed for urban skating.
How to determine the optimal height of a bicycle saddle
Пожалуй, это единственный параметр, который is regulated. There are rare models where the height of the saddle remains unchanged and depends on the growth of the bike. Determine the optimal location can only empirically. Sitting in the saddle you need to twist the pedals. At the lowest point, the leg should not be fully extended, but remain slightly bent (no more than 160 degrees). At the top of the thigh may be horizontal, parallel to the ground and be slightly tilted down. The knee should not rise above the pelvis. This suggests that the saddle is too low.
Steering wheel height
When decided on the saddle, go to the steering wheel, because their location is interconnected. To determine the height of this part of the bike, the chosen method of riding will play the primary role.
For racing tracks and high-speed driving, the steering wheel is installed below the saddle by approximately 10 cm. Depending on the individual features, +3 cm.
For aggressive driving and the same kind of tourism whenIt is supposed to overcome various obstacles, descents and ascents, the steering wheel should stand 2-6 cm below the saddle. For older people it is permissible to install them on the same level.
For walks around the city, highways and skiing on smooth roads steering wheel can be positioned saddle above or at the same level.
Saddle width
Another parameter on which cycliststraditionally pay little attention. Although he has little to do with the question of the growth of bicycles, it is completely in vain to ignore it, because much depends on a comfortable seat. If it is too narrow, rubbing may occur, and the buttocks and lower back may begin to hurt. Improper saddle can cause various health problems. If it is too wide, it will be uncomfortable to pedal, since the thigh will not be able to move freely. Sciatic tubercles should fall not on the slopes, but on even straight edges of the saddle. Then it will not cause discomfort, fall between the buttocks, rub, etc.
Find out at what distance from each otherthere are sciatic tubercles, as follows: you need to sit on a flat sand, and then measure the distance between the deepest depressions. This will be the optimal width. It should be remembered that women have a larger pelvis than men. Therefore, bicycles for the fair sex differ not only colors, but also the width of the saddle.
For the purchase is better to go to a specialty store. Here, experienced sellers will tell you how to choose a bike size, taking into account all the peculiarities of a person and the intended riding style.
