How to determine the size of the bike frame?

A bicycle frame is something without which the rest of the bike's components would not contact, would not interact with each other. Without a frame, a bicycle would not be a single whole, it would be impossible to ride on it even to the next block, not to mention long trips and bike tours.

Each person has their own height and weight. Choose an average option - for example, for a height of 175 cm you can. But only on condition that you live in such a wilderness, where the choice of a regional bicycle store is limited, and you don't want to wait from several weeks to several months for the delivery of an order from Moscow or China. In all other cases, the first parameter by which a bike is chosen is the size and size of the frame.

To bend in three deaths on a teenage bike or, on the contrary, with a short stature, barely reach the pedals with your feet, because the upper frame tube almost rests between the legs is a dubious pleasure.

You can find out the size of the bike frame using a simple (universal) method or using the most comprehensive calculation method (it relies on other characteristics of the frame and the future owner of the bike).

This simple method is based on on the meaning of a person's height. Stand against a wall and place a book or tablet against the top of your head. Mark a point on the wall that is equal in height to the top of your head. Measure this distance with a tape measure.

Find the resulting height value or the closest to it in the table.

To check that the selected frame size suits you, stand above the bike frame. In this case, the front end of the saddle should be at the level of the lower back. The distance from the top tube of the frame to the crotch should be 10 cm on average.

For ladies, the above sizes are slightly different.

The girl can check if the bike suits her in the same way - if she prefers a frame with the upper tube raised high, like on a man's bike. Take a road bike as an example. In cases where this tube is lowered, or a folding bike model with a single reinforced bottom tube is used, this step can be skipped.

Choosing a bicycle for a teenager in terms of frame size is not much different from similar actions for men and women. But in case of emergency braking, the child must reach with his feet to the road on which he is driving - if, for example, the brakes have failed.

In Soviet times, when the choice of bike models was small and only 15-20 models, the main emphasis for adults of different heights was also placed on the diameter of the wheel, and not on the geometry of the frame.

Using a tape measure and all the same board or book, measure the distance from the floor to the crotch, and not to the crown of the head. Multiply the resulting value by 0.57 - for mountain bikes (including full suspension). For track bikes, a factor of 0.63 is used. When choosing a road model, the multiplier is 0.66. On a touring bike, the multiplier for the frame size is 0.61, if a shock absorber seatpost is used, an additional 5 cm is subtracted from this value. Divide the value by 2.54 to convert the result to inches.

A more accurate and reasonable calculation will allow you to get the maximum comfort from riding the bike you choose.

To calculate ETT, the length of a line parallel to the road surface is taken. This line starts at the center of the head tube (front end of the frame) and ends at the point where the seat tube extends. The beginning and end of this line coincide with the center of the section of both pipes. The following ranges of values ​​allow choosing the most comfortable bike according to the rule using ETT values.

The latter are for racing, sports bicycles.

This approach is used in conjunction with the previous one. That is, along with the size, it is recommended to check the value of the effective bicycle length. Choosing a model that is too short will prevent you from keeping your back straight while riding. A bike that is too long also stretches the joints and back muscles.

On modern bikes it is impossible to adjust the handlebar height. An exception is city (road) bicycles with one or more speeds. You will not be able to move the stem to the desired level, which cannot be said about the height of the saddle. Let's look at road bikes for an example. Their speed is due not only to their lightness (complete absence of unnecessary parts, lightweight carbon frame), but also to the rider's fit.

Riding, overcoming the resistance of the air (and the wind), "spreading" over the frame, when the position (height) of the head approximately coincides with the position of the rear, it is much easier.

The length of the road frame is noticeably longer than that of the standard road builder. Soviet bicycles, including single-speed bicycles, were produced with longer frames than modern single-speed bicycles of the same characteristics. However, the height also affects the length of the frame.

Choosing too "short" bike, the owner must somehow compensate for this disadvantage by raising (or increasing, if adjustment is not available) the stem. The seatpost is also raised (or extended) as much as possible. All types of racing and touring bicycles have a long frame well suited to tall people - when riding uphill or upwind, such a person spends much less effort.

The main requirement for choosing a frame is still the duration and magnitude of your routes. When you buy your starting (walking) fee, you think you will save, but in reality you are not. You will pay for the savings with overtraining, fatigue and joint pain.

For a walking bike, the size of the frame is not important: the loads are small, as are the distances.

Once you have passed the beginner level, determine how high you will lower the handlebars and raise the saddle. The frame should not be short. You may be switching from a city bike to a cross country, hybrid or racing bike.

For women, the bike is chosen mainly from mountain, two-suspension, road or with a special low geometry without an upper tube (including folding). The handlebars are taken higher, the saddle is wider. For lovers of fast driving, the racing model is suitable. If the height does not fully match the specific size of the frame, the smaller one is chosen for walking, the larger one for frequent and long-distance riding.

If you buy a bike with 29-inch wheels, the frame for it is taken a size smaller than for 26, 27.5 and 28-inch wheels.

For taller and heavier cyclists (size L), bikes with a reinforced frame are chosen - thicker tubes. Too big will cause occasional perineal bruising when you get off your bike. If you cannot test the bike in action (when it is purchased over the Internet), check the ETT value, it should correspond to your height and weight.

In the following video, you will learn tips for choosing the right frame size for your bike.