Distance between bicycle pedals. Bike frame geometry

In order to choose the size of the frame you need, you should stand on level ground in shoes so that the top tube of the frame is between your legs, and measure the distance from the crotch to the top tube.

for road and road bikes, this distance can be in the range of 20-70 mm;
for a hybrid: 50-80 mm;
for cross mountain bike; 90-150 mm;
for freeride, downhill, dirt jumping and biker cross, this distance is chosen another 20-80 mm more.

These guidelines should be strictly followed, especially if you are riding in a sporty style. For cycling, fitness and riding for pleasure, something can be neglected. For example, the distance from the crotch to the top tube of the frame may be significantly less than recommended. A necessary and sufficient requirement is the ability to stand quietly on flat surface without discomfort and, moreover, the pressure of the upper tube of the frame on the crotch. Modern mountain bikes are more important to select according to the distance from the saddle to the handlebars and the slope of the body - the saddle height adjustment is quite large, and the handlebar height may not be adjustable at all.

Saddle height

Saddle height is a very important parameter. It largely determines the efficiency of the muscles, the maximum effort when pedaling and your strength endurance. The optimal saddle height is determined by the fact that with the crank arm completely lowered vertically down, the leg is almost straightened, and the angle of the popliteal cavity is 165-170 °. In this case, the pedal is horizontal, the axis of the pedal passes under the axis of the joint thumb. The pelvic area is located directly on the saddle, when the connecting rod rotates, it does not warp to the right and left. When the crank is raised to the top, the thigh should be slightly tilted down or horizontal. It is quite normal if straightened legs reach the ground with toes. If a cyclist can put his feet on the ground while sitting in the saddle, then this is a mistake in the installation of the saddle or the choice of frame size. Only representatives lower the saddle low extreme species cycling. When squatting, it is impossible to pedal for a long time and efficiently.

If the saddle is raised too high, then there is a danger of overloading the back muscles, since when pedaling, the cyclist will tilt to one side or roll over from side to side. The consequences of such trips can be not only in the form of severe muscle pain in the back, but also injuries and abrasions in the perineum.

Connecting rod length

The length of the connecting rod determines the range of motion, affects the position of the saddle, the height of the hip lift and the angle of knee flexion at the top point. On the other hand, it determines the cadence, maximum torque (thrust on the bottom), speed and throttle response of the bike.

Unfortunately, "two-legged walking" and running have been evolutionarily fixed many hundreds of thousands of years ago, and the pedal-powered bicycle appeared only in 1821. Therefore, the biomechanics of the adult human are optimized for walking, not for pedaling. The results of the research showed that the optimal step length when walking at a speed of 4.5 km / h is 0.7 m, the frequency is 105 steps per minute, and the long-term developed power is 150 W (Beletsky Yu. V. Bipedal walking. M., Science, 1984). Curiously, the optimal walking stride is approximately equal to the pedaling stride - four times the crank length. If we take the two most common crank sizes (170 mm and 175 mm), then for them the pedaling step will be, respectively, 0.68 m and 0.7 m. This coincidence is not accidental. Nature, on the one hand, and bicycle designers, on the other, came to the same result. By the way, with a power of 150 W and a rotational speed of 105 rpm on a horizontal smooth road, a bicycle can be accelerated to a speed of 24 km / h. From this follows another conclusion. Having spent the same energy, in the same time, the cyclist will travel 24 km instead of 4.5 km traveled by a pedestrian. Thus, cycling is 24 times more efficient than walking: 4.5 = 5.3 times. But this is theoretical. In practice, the efficiency is “only” 2-4 times higher due to various losses not taken into account by us.

Longer cranks (175, 177.5 and 180mm) also force the saddle to be lowered and moved forward a bit. They are easier to hit the ground when overcoming obstacles and on a bend, they somewhat limit the allowable tilt of the bike, and the pedaling frequency due to the possibility of using higher gears is slightly reduced. With shorter connecting rods (165-172.5 mm), everything is vice versa, respectively.

So, how to choose connecting rods? There are two recipes.

First recipe. A very rough estimate of crank length for a classic road bike.

For a mountain, cross-country bike, the length of the connecting rods can be chosen 2.5-5 mm more.

Second recipe. A simple principle: the shorter the leg, the shorter the crank should be. It is believed that the length of the connecting rod should be 18.5% of the distance from the top of the tibia to the ground.

None of these recipes take into account the actual size of the legs, the ratio between the length of the thigh and lower leg or differences in metabolic rate, the number of fast and slow fibers in the muscles, the tendency to sprint or stay. physical activity. The only reliable, albeit expensive, way is to try different lengths of connecting rods in order to choose the most suitable one. But scrupulously accurate cranksetting is very important for athletes and cyclists who spend 8-12 hours in the saddle many days a year. Those who like to ride for their own pleasure can happily and long years turn those connecting rods that are available, if only the purchased bike fits them in size.

Longitudinal position of the saddle

Initial (neutral) position.

With a horizontal crank and a straight fit, you can draw a straight line (plumb) through the axle knee joint, thumb joint axis and pedal axis. In this case, a deviation of plus or minus 30 mm is considered quite acceptable. If the legs are longer, then the knee can extend further. The main thing is that the knee does not reach the steering wheel, especially when pedaling in the “dancer” way (standing on the pedals). Otherwise, you need to move the saddle back or select a different frame size.

Handlebar height, stem length, top tube length

To select the height of the steering wheel, you can proceed from the following recommendations:

For racing (cross-country, road): the saddle is 50-100 mm or more higher than the handlebar, the angle of the body, counted from the horizontal, is 0-30 °.
Aggressive and sporty cycling: saddle 20-60 mm above handlebars, body angle 15-45°.
Cycling: saddle at handlebar level or slightly lower, body slope 30-60°.
Fitness, light walking: saddle below handlebars, body angle 45-60"/ 60-90°.
Elderly, children: saddle below handlebars, body angle 60-90°.

For the elderly and children, it is recommended to mount the saddle below the handlebars with a body angle between 60° and 90°. The same parameters should be followed in diseases of the spine, i.e. the body of the biker should be almost vertical.

In "old good times» road and road bikes, ATB (hybrids), touring and city bikes were produced with an almost horizontal top tube. The stem could be raised and lowered by 50-200mm, the seatposts were relatively short (150~250mm), and the frame geometry did not differ much from different types. Then, by picking up a bike for height (A), it was easy to adjust the fit by setting the saddle vertically and raising the stem.

Today, the vast majority of modern bicycles (MTV, ATB, etc.) are medium and high level have a threadless aheadset steering column, which practically does not allow you to adjust the steering wheel height. But the seatpost has lengthened to 300-450 mm, and the top tube is often made inclined. In addition, racing bikes have handlebars lower than the saddle and a long stem with zero or negative rake angle. All this, together with the long top tube of the frame, makes the landing tight, stretched, with a lot of stress on the arms, lumbar spine and neck.

Therefore, it is very important to choose a bike for yourself in size C - the length of the horizontal frame tube and the length of the stem, which in total gives the distance from the center of the saddle to the handlebars, and to achieve the correct position of the legs by setting the saddle in height and horizontally. Trying to buy a bike with a larger frame size (A) and trying to raise the handlebars won't help: the top tube and stem will be even longer, and the seating position can become even more extended and uncomfortable.

What is the way out of all this?

There are actually three ways to buy a bike.

Way one: buy an expensive, sporty, prestigious equipment and try to get used to the riding position.

Way two: it is a way of fitting the bike, upgrading and additional financial costs. Let's see what he can give. With spacer rings, you can try to raise the stem along with the steering wheel by 10-20 mm, but no more. The top tube of the fork is already cut to fit the head tube of the frame. There is another option - to lengthen the pipe by welding a suitable piece on top, which is not easy. Put a takeaway with high angle lift or adjustable (length and angle may vary). It is worth considering that a shorter stem will make the control more strict and sensitive. It is useful to install “horns” on a straight steering wheel. Instead of a straight steering wheel, you can put a steering wheel with a lift (Riser) and win another 30-60 mm. Such handlebars are very convenient - they can be rotated around the axis, changing the rise of the grip over the stem and the position of the brushes; in addition to lifting, they have greater than that of straight rudders, bending angles of 9-15 degrees. Rise handlebars are longer than straight handlebars, but can be easily shortened. The saddle can be moved as close to the handlebars as possible, thereby slightly compressing the fit, slightly straightening the back and unloading the arms.

Way three: immediately focus on the bike for a more comfortable ride, albeit not of the highest level.

Now let's go directly to practice.

Sergey Kryuchkov

Fishing... Going out into the countryside... We take a car, load our luggage - and go ahead! Which? And the bike!

The advantages of a bicycle are its sportiness, accessibility and relative simplicity of design. Cycling develops endurance, trains muscle, breathing apparatus rider, which is important in our generally sedentary life. Driving such a vehicle is allowed at any age.

One more thing important advantage- mobility and maneuverability. It is not always possible to drive along a lake or a river by car, but almost always by bike.

But in order for the ride to be enjoyable, you need to do right choice technology. Here are the main recommendations.

Bicycle type

Bicycles are divided into several classes: road, mountain, tourist, hybrid, road.

Road vehicles have a design that is unsuitable for movement outside asphalt roads. They usually have a steel frame, most often one gear, but they are a fairly comfortable vehicle.

Mountain, as the name implies, is designed for driving in the mountains and off-road. But, nevertheless, it can be used for many other purposes, including movement on asphalt roads. Such a bike has a large number of gears, usually from 18 to 27. And the equipment in most cases is designed for simply terrible conditions: puddles, mud, sand, bumps ...

The distance from the ground to the pedal is from 29 to 33 cm, which increases the permeability. The steering wheel protrudes a little forward, is straight in itself, and it is much easier to control it off-road compared to a curved one. Wheels with a diameter of about 560 mm (26 inches), wide tires (2.0 inches and above), which also has a positive effect on cross-country ability.

As a rule, there is a shock absorber: front (almost always) and rear (less often). They are necessary not only to ensure riding comfort, but also to create a better grip, for example when downhill. This type of bike can be successfully operated on highways.

A touring bike is designed for long trips with a load, mainly on highways. The wheels are narrower (1.9-2.2 inches), having a "road" tread pattern, without side lugs. The frame is longer (wheelbase), so they roll more.

Longer base compared to a road bike (up to 1150 mm)
and a more gentle slope of the fork (71-72 degrees; road - 72-74 degrees) add directional stability (it is easier to ride on such a bike without hands). This geometry provides a more comfortable ride (shakes less), but pays for the elongatedthe base will have a slight decrease in maneuverability, which is not of great importance for tourism.

But for touring bikes, the base extension is mainly due to the rear triangle, and this leads to a loss of “acceleration”, the bike goes uphill worse, and more pedaling effort is simply needed. The extended rear fork allows you to install a large backpack-pants on the trunk without touching it with your heels. The main elements of these bikes are hard-surfaced roads and groomed country roads.

Highway. Their main purpose is high-speed driving (including competitions) on asphalt roads. Wheels of large diameter (28 inches) and narrow (1.5-2.0 inches) have a purely sporty tread pattern with its minimum rolling resistance. Steering wheel in the form of "ram's horns".

Hybrid. Many cyclists unfairly neglect such bikes in favor of the latest "fancy" mountain bikes, when in fact most cyclists ride in such a way that for them, most likely, a hybrid bike would be the best choice.

Suitable for riding almost anywhere but the heaviest off-road, the hybrid bike inherits most of the features of a mountain bike, while having a higher riding position, a slightly heavier frame, 700C wheels (622 mm or 27-28 ") with tires 38- 40mm, which makes it more suitable for highway driving than mountain bikes.They have large drive ratios for smooth highway driving, while maintaining low gears for mountain and off-road driving.

Such bicycles always have fasteners not only for a flask, but also for trunks (always rear and almost always front), fenders, pump, etc., which allows you to set the mass additional equipment and accessories for tourism. But I would recommend either mountain or touring bike type.

Bicycle design

Frame. The main structural element that carries maximum loads during movement. Its classic and correct geometry: front and rear triangles, connected together on the seat tube and not having any reinforcing "kerchiefs", unnatural bends and other anomalies of engineering. The materials from which they are made: steel, more often - chromium-molybdenum alloys, aluminum and its alloys, titanium, carbon.

The most preferred aluminum, more precisely, alloys based on it. Due to their properties, the frames are light, strong enough, cheap enough, and do not corrode. The disadvantages include the complexity of repair in the field and high fragility in severe frosts.

Steel and its alloys are heavier than the above material, but they are also widely used in the manufacture of a bicycle. Titanium and carbon are intended mainly for sports, heavy duty applications. They have a high price and are practically not subject to repair in the field, but only in specialized workshops.

Shock absorbers, suspension. There are 4 types: without them; front wheel only (hardtail); both wheels (double suspension) and depreciation due to the geometry of the frame. Depreciation is needed not so much for a comfortable ride, but for tight contact of the wheel with the road - both with and without a hard surface.

Therefore, a hardtail is the most preferred option, especially if with the ability to adjust the damping force in the fork, up to its complete blocking.

"Two-suspension" is more convenient for unpaved roads, and the full advantage is manifested in high-speed movement on them (various disciplines of cyclocross).

The remaining 2 types of suspension are similar and involve short trips on densedirt or asphalt roads.

Brakes. Although they say that "brakes were invented by cowards", they are still needed. Types of brakes: rim (vi-break) and disc (hydraulic or mechanical). The most effective disc, and the simplest rim.

Braking is carried out either by the wheel rim (vi-break) or by a specially installed brake disc. Since the disc is located closer to the center of the wheel and is less exposed to mud, snow and water, it brakes better on paved or unpaved roads.

Tires. Depending on the season, they are used in winter and summer. Based on the operating conditions - highway, universal and mud (all-terrain). Each type provides the best performance "in its environment".

For example, a "road" tire has better speed performance than a mud tire, but it is useless in off-road conditions. It should be noted that in stores, as a rule, they are equipped with tires with a universal (all-terrain) type of tread pattern.

Trunk, fenders. About the purpose of the wings, I think, it is not necessary to tell. I will only say that the best protection from dirt is the so-called "full", covering almost half the length of the wheel (it is appropriate to recall Soviet technology).

The trunk can be of two types of mounting to the bike: standard (in the corresponding holes located near the rear "stars" and in the upper "feathers" of the rear triangle of the frame) and for the seat tube. If the first type allows you to carry up to 25 kilograms of cargo, then the second - no more than 5-7. You can, of course, do without the trunk. But when using a backpack, your back will sweat a lot, and you won’t put much in such a backpack ... And if you caught a trophy for five kilos? Where to put it?

What else do we bring with us? In addition to the fishing set of fishing rods, we take with us: a bicycle chamber, a pump, a bicycle first-aid kit, a medical first-aid kit. This is if we go for a day, in case of a longer trip we additionally take tourist equipment, not forgetting the compactness and weight of the cargo. For fishing accessories, I used a cut plastic canister, which I installed on the trunk.
Tips for beginners

It is best to buy a bike at the end of the season (autumn) or early spring of the next year. During these seasons, prices for bicycles are usually the lowest, however, the choice is small, and the model you need may not be in stock. It is not recommended to buy a bicycle in chain stores. The models presented in them have a bright and catchy appearance, low price, but extremely low reliability of components and assemblies. This technique is not suitable for fishing trips.

Bicycle, according to the rules traffic, is a vehicle driven by the muscular power of the rider. It equally creates inconvenience for other road users: pedestrians and cars. To better attract attention to yourself on the road, you need to "turn" into a kind of Christmas tree -
just as bright and colorful. Bright and contrasting colors are welcome in clothes and on a bicycle. In the dark or fog, the use of front and rear lights is mandatory.

A very useful safety item is a bicycle helmet. In addition to the main function of protecting the head in case of a fall, it also has additional ones: thermal insulation in hot weather and at least some protection from rain. Usually it is acquired after the first serious fall, but it is better to do it in advance.

Proper posture while cycling is, oddly enough, one of the key points for successful skating, worthy of reasoning and debate. Let's try to think about this topic.

Initially, the cyclist needs to choose the right frame size for their height and build; professional advice of consultants will be able to help him in this.

So, the initial component is selected, now it is important for us to choose the following parameters correctly:

saddle height;
saddle position;
selection or adjustment of the stem length.

Start, of course, with the height and position of the saddle. Here we will look at some of the most common saddle height selection algorithms (the first of them will be for advanced ones, and the last one is the most accessible for most):

1) “Heel Method”

This method involves placing the heel on the installed cranks at “6 o’clock” (the bottom of the crank is directed perpendicular to the ground) in such a way that the knee is fully extended, while the pelvis remains in a level position and does not warp towards the pedal, the body should not stretch behind the leg . This is the easiest or simplest method, but not the only true one, since it does not take into account the individual features of the body structure of each cyclist.

2) “Holmes method”

This method can be called a professional approach, which was created by professionals for professionals in order to reduce knee injuries in athletes. main idea this method- These are measurements of the angle of the knee joint at the bottom of the pedal stroke, using a special tool - a goniometer. Medical equipment, as we know, is not cheap at all, and if you don't professional sportsman, then it makes no sense to acquire it. Although, if there is a desire to approach the choice of landing seriously, then you can visit a special diagnostic sports Complex where such equipment is in constant use.

This method is based on studies showing the optimal knee bend angle of 25-35 degrees. Moreover, the angle of 25 degrees is preferable for people who have problems with the knee joints - for example, those suffering from knee pain due to inflammation of the tendons.

3) “Method 109%”

It was developed by Hamley and Thomas in 1967. We experimented with different saddle heights and found that the ideal fit was achieved when the saddle was positioned 109% of the distance between the rider's crotch and foot (as shown in the figure below) when measured from the pedal axis to the top of the saddle. To count at home, stand facing a wall and place a thick book between your legs (spine up, simulating a saddle). IN this moment it is important that the book is pressed against the crotch as much as possible, because when riding a bicycle you press the crotch against the saddle with all your weight. Stand straight with heels pressed to the floor, mark a line along the top edge of the book touching the wall. Take measurements several times - this way you will get the most accurate result.

4) “The Lemond method”

The method, developed by Tour de France winner Greg LeMond, is described by many as a variation on the previous method, which also uses leg length, measured from crotch to heel, to determine the optimal saddle height. But at the same time, according to Lemond's formula, the distance from the center of the carriage (and not the pedal in the lower position) to the top point of the saddle should be 88.3% of the length of the cyclist's leg. Curiously, according to Pelever's research, the saddle height when using this method is often different from the data that we get when using the "109% method". And, despite the fact that Lemond's method is suitable a large number cyclists, there are those for whom it will not be ideal.

Its essence is simple - the distance from the top of the saddle to the axis of the connecting rods should be 83.3% of the 109% method.

5) The method is simple-universal.

Sitting on a bike, leaning against a wall or a tree. Your leg should be slightly bent at the lowest position on the pedal. Usually, this is enough for 99% of cyclists. Beginners may complain that this way the saddle will be too high, but we note that in this case the fit is as ergonomic as possible and damage to the knees will be minimal.

For riding short distances or even walking, you can lower the saddle a little. This will make it easier for you to get on and off the bike.

So let's sum it up:

At least 4 of the most common methods are available at home for any cyclist - you can try and average.

Methods methods, and yet why so it is important to choose the right saddle height? The answer is simple: when pedaling while sitting in the saddle, the correct saddle height is on one side increases the efficiency of torsion pedals, and on the other hand contributes keeping the cyclist's joints healthy.

That is why it is important to take measurements responsibly - once you spend time choosing the right height, you can minimize discomfort in your knees, as well as reduce the risk of various injuries. No one has canceled the individual characteristics of the body - therefore, correcting the results obtained in plus or minus is a normal practice. By the way, there are special notches on the seatposts that indicate the minimum mandatory level of immersion of the pin into the seat tube - follow it, otherwise the pin may burst or ruin the frame.

What else can you pay attention to in landing?

Saddle tilt and its choice.

So, so, we figured out the height of the saddle - now you need to select its position on the pin. In this case, it is customary to take the starting point horizontal position saddles. The subtlety is also in whether the saddle fits you. The parameters of the saddle are selected individually, based on the biological characteristics of the cyclist's body. Much depends on its width - from the health of the pelvic organs to comfort on a long trip. In particular, do not forget that for each direction of cycling, the angle of inclination of the saddle needs its own - for dominant climbs, you can lower the nose of the saddle a little, while for descents, vice versa - raise. These parameters are very individual, therefore, for simple skiing, it is worth choosing a horizontal position as the starting point. Trying to adjust the geometry of the bike for yourself is worth it after a long ride, when you begin to understand what exactly you need.

bike geometry.

An important parameter in the geometry of a bicycle is the distance from the saddle to the handlebars. The main indicators for this are the length of the top tube of the frame, the angle of the seat and head tubes (these are the parameters that we choose in the aggregate when buying a bike or frame). However, if you haven't ridden before or don't know the geometry of your last bike, then your only choice is to trust the big name manufacturer with all-round geometry.

Takeaway.

It is worth mentioning that this distance (from the saddle to the handlebars) can be easily changed by changing the length of the stem - for example, stems from 30 to 50 millimeters are used for extreme disciplines, while stems from 60 to 120 millimeters can easily be used for cross-country.

Saddle.

Usually, when buying a bike in a standard factory configuration, the buyer receives balanced bike parameters, however, even in a stock configuration, he has his own size margin: the saddle moves on frames (the so-called “rails”) within 1-2 centimeters from the central position . With this we can easily shorten the fit, thereby unloading the lower back.

Spacer rings under/above stem.

The same result (unloading the lower back) will be caused by rearranging the spacer rings on the stem of the takeaway fork (the landing is shortened), and installing the rings above it will lead to the opposite: the landing will become more stretched - the lower back will load, but comfort and freedom of movement will appear - this is especially true for descending disciplines.

Steering wheel.

The geometry and height of the handlebars greatly affect the distribution of weight - handlebars with a rise unload the hands, but make the control less sharp and reduce the stability of the bike. In general, the steering wheel, although it looks simple, combines several geometric parameters that need to be selected only when buying a new steering wheel - this is best done with some experience of independent riding and bike tuning.

Wrists, grip and brake levers.

In terms of ride comfort, misconfigured bikes are common to see people riding bikes with twisted wrists on the handlebars. For some, they look back and down, for others, on the contrary, they are curved forward. Both of these positions are abnormal. Correct position hands on the steering wheel is as follows: the elbows should be directed to the sides and slightly bent, forming an angle of approximately 135 °. The bones of the forearm should form a straight line with the metacarpal bones of the index and middle fingers. The index and middle fingers themselves do not wrap around the grips, but lie on the brake levers - this way you reduce the load on your wrist and make riding safe and comfortable. By the way, the same applies to the position of the brake levers - they should not be tilted too horizontally or vertically - this impairs the perception of the brake levers and leads to the application of excessive forces for braking.

General and possible errors:

The key when riding in the saddle is your personal experience and the feeling of riding.: it often happens that with approximate calculated output settings, the cyclist gets numb arms or legs. This clearly points to problems in setting up the bike.

So, for example, numb hands indicate a shift in the weight of the cyclist closer to the steering wheel - the hands are overloaded, they account for most of the cyclist's weight. In this case, installing spacer rings for the take-out, moving the saddle back, replacing the steering wheel with a model with a lift higher than the standard can help. With these actions, you will shift the center of gravity closer to the rear wheel.

Leg numbness is also a common problem - here a problem in choosing a saddle is possible: a saddle model that is too narrow can squeeze the vessels, thereby limiting blood flow to the limbs. Also, pain in the knees during a long ride clearly indicates an insufficient amount of water you consume during the trip (with active pedaling, salts come out of the joint and this harms the knee), or the saddle is not raised high enough.

Many will not agree that a high saddle is good: “I don’t ride for long, and it’s inconvenient for me to get off a high saddle” - here I would like to remind you that pain in the knee joints is very unpleasant. Always remember that when you tune your bike, you save your health - you shouldn't tune your bike just for convenience - it's important to rely on the benefits for the body.

All the above tips and tricks are general recommendation and, of course, lead only to the basic setup of the bike. Finding the perfect fit for you can only be done after a few test drives to find the fit that's right for you. And most importantly - do not be afraid to experiment: in small steps, changing one parameter (and not several at the same time), you will eventually choose the optimal fit for yourself!

______________________________________________________________________________________________

12 years in mountain biking, tried all types of bikes and their suspensions - from ordinary cross-country models to heavy downhill bikes. A true fan of his hobby. Able to select a comfortable steering wheel height for 1.5 months.

You have bought a bicycle. After purchase, you need to make some adjustments to make riding a pleasure.

The first step is to adjust height saddle. The height of the saddle should be set to the length of the fully extended leg - the heel should reach the pedal when the pedal is in the lower position. This allows the muscles to rest and increases the efficiency of the cyclist.

Make sure that the seatpost is inserted into the frame at least 10cm. If this is not the case, then either you made a mistake with the length of the frame, or you better get a longer pin. If the post is less than 10cm into the seat tube, then the chance of breaking the edge of the seat tube increases greatly, and if the post is very long, then it may bend.

The position of the saddle relative to the steering wheel is selected based on the fact that the distance from the front edge of the saddle to the steering column should be equal to the distance from the elbow to the fingertips. This has already been discussed when choosing a bike size, and here you can adjust this distance a little.

Although there is an opinion that fingers should not reach the column by 1-2 cm, but everything is individual and for most cyclists this size is inconvenient. Usually saddles are sold in the middle position, so it is possible to move the saddle forward or back by 1-1.5 cm.

Also, to determine this distance “by science”, you can use the KOPS method: put the pedal at 3 o’clock, put your foot on it and a line drawn vertically down through the center of the knee joint should pass exactly through the axis of the pedal. To increase the cadence (pedaling frequency), you can move the saddle forward from this position by 1 cm. To increase pedaling power, move back 1-2 cm.

Saddle tilt selected individually. Ideally, the saddle should be parallel to the ground, however, it may be necessary to tilt it forward or backward, depending on the anatomy of the person. It is not recommended to tilt forward strongly, as the load on the hands increases - you begin to “slide” to the steering wheel, and your hands, accordingly, get tired faster. Leaning back too much can put extra pressure on the perineum, which can lead to problems, especially in men. Usually, if the horizontal position is uncomfortable, then the saddle leans forward a little.

The width of the saddle for men and women is also different. But "feminine" does not mean "big and soft." The women's touring saddle is only slightly different in width - the pelvic bones of a woman are wider than those of men. Although, many saddles are universal. The main thing is that you should sit on the saddle, leaning on the bones of the pelvis, and not on the perineum. The rigidity of the saddle is also individual and do not try to replace the saddle immediately after purchase - the stiffer the saddle, the higher the efficiency, and the inconvenience will pass by the second ride.

Steering wheel and stem

Also selected individually. Most likely, if you have chosen the right frame, then you, at least for now, will not need to change anything. In the future, after looking at how someone rides and if something does not suit you in your fit, but you like the frame, then you can try to fit the bike to yourself by replacing something (stem, steering wheel, seatpost, saddle).

However, remember that the manufacturer, when developing a frame, relies on calculations, so changing something is easy, because your hands itch, it’s not entirely correct, but if you really want to ... it’s better to first listen to the opinions of experts, at least in a cycling club.

Steering wheel also comes in different widths, from 550 to 770mm (for tourism). The wider the handlebar, the easier it is to control the bike when riding over rough terrain. The narrower the steering wheel, the easier it is to turn the bike between bumps and stones, but also the more effort you have to make to maintain control over the bike.

Stem length measured from the center of the steering tube to the center of the handlebar mount.

Typically, stems 60-100mm long are installed on the bike, however, there are stems with a length of 10mm and 140mm. For tourism, offsets of 90-100mm are usually used. The longer the stem, the more horizontal your landing will be. and, the worse the controllability (fidgetiness), but the better bike goes in a straight line.

If you want to install a stem longer than 120mm, then most likely you just have a short frame - do not torture yourself or the big one.

Also, offsets come with different angles of inclination (height).

It is most convenient for beginners if the landing is vertical, but it is not correct for touring. If the steering wheel is too high, it will make it difficult to go uphill and worsen pedaling efficiency. If the stem is very low, then you will improve aerodynamics, however, because. tourism is not a highway race, you can earn back pain and extra pressure on the perineum. Also, do not try to compensate for the length of the stem by pushing the saddle back.

Approximately the height of the rudder (removal) should be such that the back is inclined to the rudder from the vertical by 30 °.

Bicycle frame geometry is a parameter that determines the behavior of your two-wheeled bike, its essence, character, level of compliance with your height and your own capabilities. The geometry of bicycle frames consists of the angles at which the frame tubes are welded and the length of these tubes. In their combination, they form a different height of the bottom bracket assembly (if it’s very rough, then the height of your feet from the ground), can vary the distribution of the rider’s mass along the axes of the bike, create different angles of the steering column, changing the sharpness and control features, create different lengths of the base, front and rear triangle, vary the height of the bike.

Each of these parameters has a direct impact on everything, and when choosing a bike, riders are often puzzled by what frame geometry they should choose. We will summarize the main geometric characteristics of velorams, try to explain what and how each feature of the geometry directly affects, and explain why it is impossible to build a universal bicycle with ideal characteristics.

Components of frame geometry

Frame size tied to the length of the seatpost tube. Sizes M, L, XL, 17, 19, 21 inches all come from her size, but if the manufacturer of the bike is serious and smart about designing geometry, then changing the size will affect other geometric characteristics. In a good frame, every detail is tightly interconnected.
What does growth affect? If the bike is too big for you, then you will rest your crotch against the top tube in the place of the frame standover (see diagram), if the size is small, then you will have to unnecessarily pull out the seatpost, and the frame will often turn out to be also short (you will touch the steering wheel with your knees) .

But everything is not limited to this. A small size makes the bike more comfortable for performing many tricks, and in the case of a trial, the minimum size of the seat tube allows you to carry out the maximum possible preload of the bike under you, followed by jumping on obstacles.

The essence of the size of trial geometry in one frame

Effective frame length- a value dependent on the length of the front triangle and the inclination of the seatpost, measured from the top of the head tube to the seatpost (in the horizontal plane). If this value is small, then the bike will feel good on technical winding paths. Often this geometry is correlated with short feathers and eventually develops into a very interesting “shorty” for technical skating with a maximum degree of freedom in movement. Longer bikes, when achieved not by shifting rider mass rearward but by lengthening the top tube of the front triangle, make for a comfortable seating position for maintaining high speeds and navigating uphill sections.

Short frame for dirt jumping

Steering angle- one of the explicit destination classifiers modern bicycle.

On bikes for downhill and fierce freeride, the corner often collapses - the fork, like a bulldog's jaw, begins to bulge forward relative to the frame. Steering loses its sharpness, making taxiing more stable and prone to straight paths. And this is important when downhill. Also, when the angle of the steering column is littered, the fork turns out to be a turned movable part of the shock absorber towards the encountered obstacles, and as a result, the shock absorber begins to effectively work out any irregularities encountered. And the reverse side of the coin is the loss of controllability and the placement of the fork that dampens the efficiency. The latter is especially seriously felt on the rise - the bike seems to rest against the wheel of every encountered stone.

On road bikes, fork tilt is minimal ( steering column practically not littered), a little more steering tilt on cyclocross bikes. In cross-country geometries, the lean is still negligible, but allows you to harmoniously combine decent rolling and climbing comfort with at least some bike control on descents. The AllMountain geometry has more headroom which makes the bike more interesting on descents with a loss of speed on flats and uphill sections of the course, on DH bikes climbing uphill will require a huge waste of energy, but on the descents themselves the control will be at its best. . In trial geometries, headstrap allows you to get a longer wheelbase for easier navigating obstacles, but tricks through the front wheel, as well as overall control of the bike, will be reduced.

Head angle is not always enough for a cross-country bike, making the descent completely dependent on the exact miscalculation of the trajectory down, as can be seen in this photo.

Seatpost Angle- an important element in the distribution of the mass of the rider along the axes of the bicycle. The seatpost tucked back takes the weight of the body with it, partially unloading the front wheel. As a result, in combination with a short wheelbase, this allows for a direct “comfort” level fit, and in combination with almost everything else, it improves the ease of yanking the bike. The latter is important in the extreme disciplines of cycling.

If the angle of the seatpost is not littered, then the mass is distributed along the axes of the bike more evenly, and as a bonus, the rider receives optimal body placement relative to the bottom bracket assembly (it becomes easier to pedal for a long time).

Carriage height is not just the clearance of your bike, but the height of the center of gravity, which affects the control over the horse. Almost everywhere, except for the trial, manufacturers tend to lower the bottom bracket (in the trial, a high bottom bracket improves the stability of the bike in the rack by rear wheel and simplifies the process of performing most tricks).

On freeride bikes, the bottom bracket height relative to the axles often tends to zero, on country bikes the height is negative. Low-mounted pedals are easier to turn uphill, while the zero height relative to the axis gives the range of the fork to go through obstacles.

In bikes for street and park, the situation with the bottom bracket is ambiguous. The low bottom bracket improves flight stability, and is generally viable for dirt and park AIR riding. On the other hand, it is impossible to use pegs and perform some street tricks on a low carriage. Zero carriage is a popular option in the street.

The high bottom bracket adds stability in trials when standing on the rear wheel.

Rear chainstay length- the most important parameter of the geometry of the bicycle frame. Excessively short chainstays make climbing uphill and the strength of the whole structure difficult (more loads end up on the head tube), but they give good handling and freedom in performing many tricks. Long and moderately long chainstays provide manufacturers with an unprecedented field for the most complex bicycle engineering. In them, you can lay the bike's rolling moments when handling obstacles, reduce the negative stiffness of the frame, improving its comfort and rolling performance. A good XC bike will never have too short chainstays, just like a serious downhill bike. And never will a modern fan-riding and stunt bike have long frame stays.

Feathers are the most complex component of a bicycle. A well-engineered rear triangle is only found on a decent level of frame.

But I still want a versatile bike!

The golden mean of the cycling world is All Mountain bikes. Their geometries are the most balanced and such bikes, with proper skills, allow you to enjoy riding in almost any situation. But it should be understood that All Mountain will give way in all more specialized options.

Universal bicycle frame geometries exist, but there is no perfect solution for all disciplines.