There is more than one conditional classification skiing having the right to life. Moreover, the manufacturers themselves from season to season often castling their models, moving them in catalogs from one category to another. Introducing conditional classification from our expert Sergei Garibov, which will help you navigate the varieties of alpine skiing and manufacturers' catalogs.
Carving skis
A carved turn performed by Fischer pro rider Alexander Gordeev.
Carving (piste) skiing- a type of ski designed for skiing on prepared slopes (on piste). Such skis repeat the geometry of sports skis, but they are more comfortable, softer in deflection and not as hard in torsion, not as “strict” (that is, they “forgive” some mistakes) as sports skiing.
Such skis provide the ability to ski in deep arcs, short or wide. Typically, the waist width of a trail ski is in the range of 68-78 mm. Cross-country skis have a deep side cutout - the turning radius of the ski is from 10 to 19 meters.
What is carving
Theoretically, for a good cross-country ski, such geometry, together with the correct distribution of the stiffness of the ski, provides it with ease of entry into the turn and the ability to pass the entire slope "on the edges", without slipping the ski sideways. This technique of turning (without side slip) is called "carving" and is considered modern skiing technique. It arose along with the advent of carving skis (skis with a deep sidecut) in the second half of the 1990s. As they say now, at the turn of the century, a “carving revolution” took place in alpine skiing. When skiing on carving skis, the skier loads both skis more evenly, unlike classical technique with a load in a turn on one ski, external to the turn. When skiing on modern skis, on average, 60% of the load goes to the outer ski in a turn, 40% to the inner one.
The transition to carving skis had several serious consequences:
- The initial training in ski equipment has been simplified, and, accordingly, the number of skiers has increased.
- The average controlled speed of skiers has increased, and in general the possibilities of skiers on the slope and, accordingly, the pleasure of skiing.
- The outflow of skiers to snowboarding has decreased (the simultaneous appearance of wide skis and twintips also played a role here).
Sasha Gordeev carve on freeride (!) Fischer skiing Big Stix 122 (size 190 cm, turning radius 20 m).
What are carving skis for?
Carving skis are ideal for the initial training in ski technique. If a person has good physical data, is really set up and wants to learn how to ride, he needs to be helped in his intention by picking up the “right” skis for him. In what sense are "correct"? In such a way that the skis themselves helped him master modern skiing equipment - the technique of carved turn, that is, carving.
Trail (carving) skis are well suited for skiing on soft or hard (icy) prepared slopes, but not for skiing in deep or unprepared snow.
For beginners and advanced skiers, carving skis are usually chosen 10-20 cm shorter than the height of the skier (depending on the weight of the skier, his experience, skiing speed and preferred turning radius). For experienced skiers for skiing in the mountains in large arcs at high speeds, skis are selected 10-20 cm tall and higher with a large (15-20 meters) turning radius. On small slopes and frequent turns - short skis (smaller height) and with a radius of 10-13 meters.
The fact is that in addition to all the above classifications, ALL skis are divided into three large classes:
- Skis that carve well will carve well.
These are, first of all, sports skis (race), expert cross-country skis, cross-country skis for advanced skiers, sometimes (best) cross-country skis for intermediate and beginner skiers. That is, these skis are designed for those who love speed on the prepared slope.
- Skis that go well with side slip.
The second class usually includes all skis for beginners, for children, for everyone who wants to ski at low speeds. These skis are designed to control speed with side slip. Most freeride skis, park skis, most of the all-mountain skis fall into this class. Freeriders and expert all-round skiers who ski at high speeds in difficult snow conditions also need to control their speed with side slip.
- The skis are universal in technique, that is, they carve perfectly and at the same time turn easily with lateral slip.
The third class includes a small number of the best trail and universal (All mountain) skis and an even smaller number of freeride skis.
Universal skis (All mountain)
Most skiers want one pair of skis for everything. This is a normal desire for any “normal” (average) skier, so that during a trip to the mountains on these skis you can both grab the track and jump along the hillocks, and, if it suddenly snows, get out of the tracks. We must admit to ourselves that such skiers — majority. For them, manufacturers make this most massive class of skis.
All-mountain / All-terrain / Allround skis - universal mountain skis. They behave quite well on snow-packed slopes, they also behave well on broken slopes, on soft mounds and in shallow virgin soil. However, in each of these situations, they are significantly inferior to specialized models.
The waist width of universal skis is usually in the range of 78-100 mm. The turning radius of these skis usually varies from 13 to 21 meters. The length of universal skis is usually selected in the height range of the skier +/-10 cm. The class of these skis is quite diverse, because everyone interprets the very concept of versatility in their own way. For some, behavior on a prepared slope is more important, for someone - on hillocks, so it is quite difficult to formulate the general properties of universal skis for the class. But I'll try:)
Width of universal skis
The width of the ski is 78-100 mm - definitely more than a ski for prepared slopes, but less than a freeride ski. That is, it is easier to ski on these skis in shallow virgin snow than on trail skis, but much more difficult than on freeride ones. The more the orientation of the universal skis off the track, the wider the waist. The golden mean for expert all-round skis, I consider a waist of 86-95 mm. With this width, the skis are still quite easy and quick to edge over, allowing carving, and at the same time, this width is quite sufficient for skiing in light alpine virgin snow.
Technical versatility and sidecut
Universal skis should be universal not only in terms of the surface on which to ride, but also in terms of skiing technique. That is, it should be easy to ski on not only modern carving techniques (carved turns), but also “classics” (turns with side slip, controlling turns, “godille braking”). For this, progressive sidecut technology is often used, which gives an aggressive corner entry on a hard slope, forgiving behavior in virgin snow and broken snow.
Thanks to the progressive sidecut, the ski builders managed to combine an aggressive geometry with a wide waist. The standard side cutout is a fragment of an arc of a regular circle. In other words, the sidecut radius remains unchanged at any point, from the tip of the ski to its tail. This works well on skis with a narrow waist, but becomes a problem on wide skis, especially on difficult snow.
The progressive sidecut, in turn, has a more complex shape - its radius increases as you move from the nose of the ski to its tail. As a result, a reduced sidecut front radius gives us confident and quick corner entry on hard prepared slopes, while a larger rear sidecut radius provides a more forgiving behavior and less aggressive turn shape, making it easier to drop heels in broken snow and powder. .
In this regard, these skis are usually less suitable for the initial training of beginners in modern skiing techniques than piste models. Beginners are very afraid of speed, and all-purpose skis provoke them to make turns with side slip and interfere with the consolidation of carving skills, which are considered basic in modern ski technology. It is much easier to learn carving first, and then master the “classics” than vice versa. My point is that generally good all-round skis are for at least intermediate and advanced skiers.
turning radius
The turning radius is average, the most common radius is 15-16 meters. More than a slalom ski, but less than a giant slalom or freeride ski.
Rocker on universal skis
Recently, all skis (including carving) use rocker technology. On universal skis, it is also usually used to increase cross-country ability, ski stability when driving on broken slopes, and ski buoyancy when going to virgin lands.
What is the difference between a rocker on universal skis? The answer is simple: on universal skis, the early toe lift zone is shorter than on freeride skis (usually does not exceed 300 mm, on freeride skis it easily reaches 500-700 mm) and the toe lift is less than on freeride skis. The rocker on universal skis is both front (Tip Rocker) and double (Double Rocker), less often a low-profile full rocker is used (Full Rocker Low uses Volkl in its All mountain skis).
Why do you need universal skis
By and large, All-mountain skiing can be described in two words: skis are ideal for broken slopes (Cheget, Dombay, Alpine resorts after 13:00 CET).
Freeride skis
Alexander Kaniovsky, head of the Fischer marketing department, freeriding in Saalbach.
Freeride- skiing or snowboarding off the prepared slopes and, as a rule, outside the service area of the ski industry.
It is believed that it is when skiing on untouched snow that all the possibilities of skiing and snowboarding are most fully revealed. At the same time, off-piste skiing promises a lot of dangers associated with unfamiliar terrain, for example, the possibility of avalanches. Beginners should not be in a hurry to leave the track in the mountains, for this they should have certain skills in skating technique.
Photos from the personal archive of Sergei Garibov.
The main characteristics of skis:
- length (size)
- width
– stiffness (average, static/dynamic)
- distribution of stiffness along the length of the ski
- torsional stiffness (torsional stiffness)
— geometry (sidecut depth, sidecut radius, sidecut law (shape))
- waist width (width of the ski under the boot)
- toe length (distance from the front binding to the toe of the ski)
- vibration characteristic (the ability of the ski to absorb vibrations)
- impact absorption.
What are these characteristics?
1. Length
More long ski:
- more stable at speed (when skiing flat)
- more moment of inertia - better stabilize the position of the body
- easier to slow down (larger edge length), especially when riding in the mountains
- go better on virgin lands (deep snow)
More short ski:
- easier to turn (more nimble)
- it is better to ride on short slopes (you will have time to make more turns)
- better on ice (more specific pressure on the edge - better cut into the ice)
- better on hillocks (more nimble)
- lighter in weight.
2. Width
Narrower ski:
- better on ice (in the limit - skate)
- better on hillocks
- more lively and agile
- lighter in weight
Wider ski:
- goes better in deep snow / virgin soil
- higher stability at speed (on a flat slope)
- higher stability (confidence)
3. Ski stiffness
Softer ski:
- starts to work correctly (flex in an arc) from lower speeds
- better absorbs uneven terrain
- Properly designed soft skis
better hold on the ice (when skiing on the edges)
- go better on virgin lands (soft snow) Harder ski:
- more impulsive - more powerful skating, powerful rollover from turn to turn
- better hold on ice (with lateral slippage of the edge)
4. Geometry
Information block and catalogs usually contain the following information:
140
- ski size in cm
110/73/99
- measurements of skis in mm: the width of the toe, waist and heel, respectively
11,7
- sidecut radius in m.
The last two values, that is, measurements and the radius of the sidecut, determine the so-called "geometry" of the ski. The sidecut radius is measured using a special technique, and it can be used to judge the ability of skis to carve turn.
The larger side cut(smaller sidecut radius), the more the ski tends to go in an arc and, therefore, allows better control of the speed when carving skiing.
The smaller the side cut(larger turning radius), the more the ski tends to go straight, therefore, allows faster skiing.
Skis with large (deep) sidecut (small sidecut radius):
- Easier to turn
- better hold on ice and on steep slope(when skiing on the edges)
- they hold worse on ice (with side slipping of the edge)
- go worse on bumps and bumps.
The smaller the size of the ski, with the same measurements, the more steeply the ski is able to turn when carving.
5. Waist Width(width of the ski under the boot)
The narrower the waist, the higher the speed of edge-over (it is easier to enter the turn) and handling, the wider - the better ski behaves in deep snow.
6. Toe length(distance from the front binding to the toe of the ski):
Large toe length - better behavior in deep snow, the ski floats better in virgin snow. Shorter toe length means easier and faster turn entry.
Types of modern skis:
- Reisling - sports - for participation in competitions, for special slalom, giant slalom, mogul, etc.
- Freeride - skis for skiing outside prepared slopes mainly in virgin lands (deep fluffy snow), for example, Salomon AK Rocket.
- Olmountain - universal all-relief (the most versatile, for any slopes and snow conditions, for example, Salomon X-Scream.
- Frikarv - for expert skiing mainly on prepared slopes, although in this group one can distinguish the so-called universal carving skis, which are less sensitive to uneven terrain - for example, Salomon Crossmax.
- Sportcarv - for amateur skiing at low speeds, mainly on prepared slopes.
- New school freestyle - trick riding and jumping both in the snow park and on ordinary slopes with varying degrees of training, for example, Salomon Teneighty.
- Supercarv, or Fan-carve, or radical carving - "carving" riding, as a rule, without sticks, with a strong blockage of the body on the slope. Due to the extremely deep sidecut, strong centrifugal force is generated when riding, for example, the Salomon Axecleaver of the Streetracer series.
- Skiboards, or snowblades - special carving skis, usually less than 1 m long. They are produced with lightweight fastening without the possibility of automatic operation when falling, which is allowed by international safety standards, provided that the skis are shorter than 1 meter
Success in skiing directly depends on the competent selection of equipment. Putting on what was and flying from the mountains is not our method! At least it is not safe and you are unlikely to get pleasure from such skating.
3 characteristics that determine the quality of skiing:
- Geometry or size - the width of the skis at three points: nose, heel and waist, as well as the radius of the sidecut formed by them.
- Profile and type of deflection.
- Ski length.
About how correctly we already wrote earlier, in this article we will consider the nuances of selecting sizes and types of deflections for skiing. These two characteristics directly affect the comfort of edge-to-edge arcing, descending stability and confident control at high speeds.
Traditionally, ski equipment is classified by skill level: children, adult beginners, amateurs, advanced and experts. But by and large, the whole choice in this category comes down to two components:
How do you want to ride? Slow or fast, with aggressive carving technique (sharp turns) or not.
Where do you want to ride? On prepared, groomed trails with cleared snow or off-piste, on virgin soil and snowdrifts.
Let's deal with each indicator in order to understand which skis should be chosen and what to focus on in general.
Varieties of skiing by type of ride
- Racing - the general name of skis for downhill. Under this name they unite the carving style of riding. Almost all amateurs and experts prefer either this category or All-mountain.
- Freeride - skiing off the prepared slopes. This includes hilly terrain, virgin lands with deep snow. They are also called powder skis and the main distinguishing feature- waist width from 115 cm.
- Freestyle - skis for stunt riding and performing acrobatic elements in parks. You can also find the names park or pipe, meaning how to ride in special parks.
- All-mountain, Allround - universal models, perfect option for newbies.
Alpine skiing has two sides of the same coin. If you prefer speed, then you need skis of one design, and if you prefer maneuverable riding with aggressive carving technique (cutting arcs), then a completely different one.
Universal skis (All-mountain), which, we advise all beginner skiers, are not suitable for experienced people who want to ski in different conditions. For every style of riding, you need your own pair of skis!
In the article, we try to duplicate all Russian-language terms on English language, because the marking of alpine skiing is usually done in English and it will be easier for you to navigate this way. And then how many sites in Runet, so many variations of terms.
How to choose the size of skis (geometry)
By the shape of skis, we can predict in advance how they will behave on the track.
When choosing a size, they are guided by three characteristics - nose, waist and heel width, are always measured in millimeters (see photo on the left). These three meanings together form , which is responsible for passing turns and cutting arcs.
In the screenshot on the left, the radius is displayed in meters. This is an average figure, which also depends on the length of the ski. One model with the same width, but with a different size will have a different side radius.
The larger the sidecut radius, the better the skis enter the turns and pass them faster:
Skis with a short radius, say 14-16 meters, will turn fairly quickly. But 22 meters will be less maneuverable, but will be able to develop great speed and not least because of the width of the waist.
Nose (Tip): this point is responsible for the beginning of the turn of the ski. Wider nose (approximately 120mm and above) floats easier on soft snow and will good option for descents on unprepared slopes.
Heel (tail): the back of the ski helps to handle turns. Wide heels are popular among experienced skiers. When cutting fast turn, wider tail resists side slip and maintain speed. Beginners should not choose a wide heel, they still will not be able to fully appreciate all the possibilities.
Waist Width: no less important indicator and is responsible for turns and behavior at speed. I would even say that it is the ratio of all three points that is important, and not just one.
With a narrow waist, the skis go into turns well, easily cut arcs. Suitable for prepared slopes. With a wide waist, skis keep speed more stable and behave better on unprepared slopes, virgin lands, drifts with snow.
The standard waist width for All-mountain skis that we recommend for beginners is 70-80mm.
Also, almost all have the same lateral radius, so you can’t go wrong with this characteristic. But, nevertheless, remember about it and ask a consultant in a sports store about it.
Why All-mountain? After all, a beginner will obviously not engage in freeride outside of prepared trails and descend on high speed with aggressive riding technique, so he prefers to choose shorter alpine skis, with a universal side radius indicator, an average waist width. Such skis will easily enter short turns, the beginner will be able to quickly master the basics of carving riding, as the most common type of skiing.
Profile or bend of alpine skis
Camber is a slight upward camber in the center of the ski. A traditional deflection that has been used for many years. The main idea is that under the weight of the skier, the skis bend in the opposite direction, due to which the area of \u200b\u200bcontact with the snow increases.
Camber Provides good speed, and most importantly, stability on it. Skis with traditional camber are not suitable for freeriding and skiing on soft snow.
Rocker is an inward deflection at the toe, or at the toe and heel. It is also called reverse camber. Sagging under the weight of the skier, the nose and torture rise up. Alpine skis with moderate rocker are ideal for beginners, they make it easier to cut carving turns.
Many skis have combined shapes - a rocker at the toe and heel, a camber in the middle. It's the perfect combination of the cornering control of a rocker ski and the speed stability of a camber. The cambered midsole provides good handling at speed and in hard snow, while the rockered toe and heel provide good flotation on virgin snow and easy corner entry.
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Do not forget about ski poles, how to choose the right size and material, we described in detail in this article -
Look at the diagram below for examples of popular profiles:
As you can see, manufacturers use different combinations of camber and rocker, adjusting to the needs of each skier. The percentage of sag is responsible for the style of skiing they are suited to.
So what to choose for regular skiing in a ski resort?
Answer: no profile can be called bad or good. Camber improves handling and gives control at speed, therefore, in universal models, it occupies from 85% of the total area, 15% is allocated to the rocker. But freeride, powder are already equipped with a rocker from 20 to 60%. It is understandable, on virgin lands and deep snow you need controllability and cross-country ability.
Remember that the percentage of this or that bend in alpine skiing is good or bad. Here the main ratio of magnitudes!
If you are also asking this question, then take All-mountain skis!
| pros | Minuses | ||
| short and narrow | Long and wide | short and narrow | Long and wide |
| Comfortable and easy to maneuver | Suitable for any weight category, no subsidence under the snow | Under a heavy skier, they fall through the snow, you need to choose the right size. | Poor maneuverability |
| You can ride in places where the snow is icy and has a rigid structure | Accelerate to high speed | Speed is low | Not suitable for icy hard snow trails |
| Suitable for trails where the surface is uneven and bumpy | Better braking due to larger contact area | Long braking | |
| Suitable for riding in deep snow | Not suitable for virgin and freeride | ||
Alpine skiing for women
Most often they are softer and with mounts shifted forward, most suitable for the center of gravity of the female body, located below the male.
Universal women's alpine skiing with good reviews:
- Salomon CIRA with LITHIUM 10W mounts - have a side radius of 13 meters. The price of such a model is from 22 thousand rubles;
- Atomic Vantage X 77 CTI W;
- Fischer My Mtn 80 - the model is suitable for already progressing skiers with the skills of active, carving riding.
Video: how to choose skiing for beginners in 3 minutes
Translation of a useful informative video from the American company rei.com especially for WayEmpire.
Watch out for discounts
Do not forget that the price of ski equipment has a seasonal surge and it is best to buy them either at the end of the season (March-April) or already during the season. At this time, the price can drop up to 50%. The price hike peaks in autumn!
More great way save money - buy alpine skiing of past seasons. Their prices are often lower, and the technical difference is not so great and difficult to notice, especially for beginners.
We do not advise beginners to choose skis themselves, it is better to trust professionals, and for the first season to generally ride on rental equipment, try different lengths and geometry, see what type of ride you like, and from next season pick up your first skis.
Answers on questions
What brand of alpine skiing is better?
This question is easy to answer, since the ski market is conservative and new and successful brands rarely appear. Look out for: Atomic, Fischer, Leki, Rossignol and Salomon. These brands have stood the test of time, skiers and ski cup competitions.
Where is the best place to buy skis?
If you buy in Moscow, then in the specialized stores Kant, Sport Marathon, or Sportmaster, only some professional department, where there will be qualified specialists who can show and tell the beginner. Or good online stores.
We do not recommend taking used skis, especially after 2-3 riding seasons.
What time to put a child on skis?
Ski schools accept children from 4-5 years old. You can put, as they say, from the cradle, but now they will start skating sanely from five years. And at the age of 7-8, you can already fully engage in sports schools.
Should I choose with or without mount?
Modern universal skis all come with bindings. One has only to ask the consultant to set them to the size of the boots and show the principle of the mechanism.
And important element equipment is skiing. And the question of choice is especially acute for those who are just going to master the technique of skiing.
Properly choose skiing for beginners will help the advice of workers in this area. Depending on the characteristics and basic parameters of alpine skis, they are selected according to the skill level of the skier.
It is worth noting that alpine skis differ from each other in the shape of the nose, heels, the narrowness of the middle part and the softness of the products. These quality characteristics give alpine skiing stability with a smooth ride and make them convenient for learning and developing techniques.
On a note:
Types of skiing
Alpine skiing classification - the dependence of ski types on the parameters and characteristics of ski equipment. From the article you will find out what kind of alpine skiing you ride and how they differ from other varieties.
Important characteristics of alpine skiing
However, it is important to focus not only on the model of the product, but also on a number of its technical characteristics:
- Lenght and width
According to the structural structure, alpine skis differ in length and width.· long skis - They have the ability to develop high speed when skiing on a plane;
- Give greater stability to the position of the body;
- They drop speed well due to the increased length of the ski edge when descending from the mountains.
· shorter skis - Lighter in mass, nimble on hillocks and more maneuverable on icing;
- Increase the ability to make more turns on the slopes of small or too narrow tracks;
- They exert specific pressure on the edge, deepening into the snow surface.
· wide skis - Develop a stable speed on flat slopes of the tracks;
- They overcome deep snow and virgin lands well, which is a huge advantage when skiing through the forest on unequipped tracks.
Useful article:
Selection of skis by height
How to choose the right skis for your height? An article about how important a well-chosen ski length is and why. We have given important recommendations that you should follow when choosing ski equipment.
The main problem faced by those who wish to purchase their own ski kit is the ability to combine the good characteristics of mountain skis with their level of skiing and versatility for ski slopes of any complexity.
- Rigidity
The stiffness of mountain skis is understood as its ability to deflect under the influence of the body weight of the skier. Rigidity is primarily responsible for handling, i.e. how difficult / easy it will be for the skier to cope with his skis when skiing on the slopes of the mountain. Hard directional skis with high values of this characteristic are more for professional skiers who have impulsiveness and powerful alpine skiing with skillful turns from turn to turn.
- Vibration damping, flexibility, torsion stability
Based on the characteristics when choosing skis, you need to know other features such as vibration damping, flexibility and torsional stability.· vibration damping - Vibration damping is determined by the behavior of the ski when gaining medium or high speed. Most of the vibration absorption increases the accuracy of movement on arcuate tracks, gives additional stability when passing bumps and at the same time the edge cuts well into the ice surface, which thereby gives stability to skis when skiing at high speeds.
· flexibility - Flexibility gives springy and elastic bending of the ski under the influence of the weight of the skier.
· torsion stability - High-quality ski assembly, taking into account resistance to deformation, determines the torsional rigidity of the skier's stability, and is one of the main features.
- Advantages:
Facilitates riding at low speeds (automatic tip and heel counter) and simplifies skating mistakes. - Disadvantages:
The low torsional stiffness of the ski keeps it on ice somewhat worse.
- Advantages:
Recommendations and tips:
How to choose skiing?
Here - we will tell and explain in an understandable language how to choose skiing when buying. We indicate important points, which you can not do without when choosing skis for skiing on the ski slopes.
- Turning radius and sidecut
The turning radius is the main characteristic by which the ability of certain skis to turn while passing along the slopes is determined. Larger side cuts with reduced radius for better arcing with controlled speed. Conversely, with a smaller sidecut and a larger turning radius, the skis go straighter and add speed when skiing.
Advantages of skis with a deep sidecut and a small radius:- Easily fit into a turn;
- Steadily keep the trajectory of movement on the ice surface and steeper slope.
- On ice, when the edge slips along the ice, they lose stability;
- They glide a little worse on uneven terrain and mounds.
- Waist Width
Of no small importance in alpine skiing is such a characteristic as the width of the waist of alpine skis. This indicator determines the behavior of skis when passing through deep snow or ice. Therefore, a narrow waist contributes to the development of high speed when changing edges, easy fit into turns and increased handling. Wide waist helps tread through deeper snow; - Toe and heel width
Important for lovers of ski holidays and the role of the length of the toe of skis. The wider the tip of the ski, the more confident the skier enters the turn. Such skis give an advantage when passing tracks intended for slalom trials. Such a characteristic as the width of the heel of the ski is also important for lovers of slalom and carving. The wider the heel, the better the arc at the end of the turning maneuver;
- Operating speed range
The operating speed range is considered satisfactory if the alpine skis make the correct course in an arc. Wide ranges of working speeds give the skis versatility.
Good riding!
We hope our article was useful to you.
Of course, the turning radius is determined not by the ski, but by the skier 🙂 Nevertheless, the ski must have its own “favorite arc”, along which it goes like on rails. The curvature of the arc changes with the edge angle. What is especially nice is that skis do not need a skier at all to cut a “favorite arc” (he can be replaced with a load). And if the desire of the skier to go along the arc coincides with the ability of the skis to cut just such an arc, then the perfect carving will probably turn out. In this note, I will consider how the ski sidecut radius and the turning radius are related for Atomic skis Redster FIS SL 165 cm (2016).
Let me remind you that such skis of the “club shop” type are being considered.
Geometric parameters are written on the "topsheet": length 165 cm, radius 12.5 m, toe width 117.5 mm, waist - 65.5 mm, heels - 101.5 mm.
A few words about mathematical transformations. First, the shape of the sidecut (work area) needs to be slightly expanded so that the width of the toe and heel matches, and the zero mark must be placed at the narrowest point of the ski. Then the form can be edged. To obtain a “trace in the snow”, you need to divide the coordinate of the side cutout obtained in this way by the cosine of the edging angle. For deflection, multiply by tangent. But in this note, the deflection calculation is not used. Next, you need to get the “X” coordinate from the assumption that the length of the edge does not change during edging (that is, the toe and heel are slightly closer). To do this, you need to calculate from the consideration of triangles the changes in the “X” projection at each measurement step (I have it after 1 cm) and correct this change in length from the middle of the ski to the edges with the sum with “accumulation”. Well, then turn the resulting curve back 🙂
If we proceed from the fact that the shape of the side cutout fits into a circle, then what shape of the trace will turn out after edging - I don’t have enough imagination trace shape. Here is the result:
It can be seen that such a transformation gives a trace that is ideally round on the scale of the graph, that is, it is quite possible to speak of a turning radius. I note that at angles greater than 80 degrees, the circle hitting the trace worsens. The value of this radius turns out to be quite strongly tied to the radius of the side cutout (equal to 12.3 m).
It can be seen that edging up to an angle of 45 degrees corresponds to a change in the turning radius from the “initial” 12.3 m to 8.7 m, and this is approximately the same from the point of view of the trajectory on short slalom turns. At an extreme angle of 60 degrees, the turning radius is 6.1 m, which is also not very similar to what happens on a slalom course.
Mattias Hargin, 2017. Photo from his blogNear the pole, the skis visually go as if “around the skier”, which corresponds to a turning radius of less than two meters. This is the edging area from 80 to 90 degrees! But is it even possible to talk about cutting the arc at such angles?
Review of experiments on measuring edge and turning radius
Unfortunately, the answer to this question is generally not very pleasant. There is no carved arcing on the slalom track at all, and the edge angle of the skis does not depend much on what the ski with its sidecut shape “would like”. And in general, 20 years ago, skis with a completely different sidecut could also turn over strongly. I would not like to plunge into such reasoning myself. For this, the network has scientific papers. Sensors are placed on the athlete and skis, the passage along the track is recorded by several cameras, the shape of the track and the cut groove are analyzed. Articles write about different things, but one of the conclusions that concerns this note is the same: a skier is riding, not a ski, the edge angle depends on the turn that he needs to make, on the technique, on the speed, on the surface ... They rarely remember about the sidecut of the ski 🙂
I will give a figure with selective experimental data.
Above are the phases of the turn, taken from a real athlete. On the graphs, data on edge angles and the degree of drift (the angle of ski mismatch with the direction of movement). Data for three skis with different radii, the authors believe that the curves are approximately the same. He gave a drawing in order to show that the edging of skis is not at all connected with the incised arc. I will also give graphs of edging and the actual turning radius, which goes with a clear drift before the pole, and after the pole, we can say that it is insignificant. It can be seen that the turning radius is consistent with the edging (the stronger the edged - the steeper the turn), but weakly depends on the radius of the side cutout of the ski.
In general, there is nothing new in the fact that a skier rides, and not a ski 🙂 But the topic of the note is to see how the ski “wants” to ride. To do this, you need to understand at what corners of the edging it can cut the arc. There is no clear answer. So I have to rely on what I see. Based on my observations of free descents on a gentle hill and a “morning soft ice” surface, cut arcs throughout the turn are possible at edge angles up to 45 degrees. The corresponding calculated turning radius of 8.7 meters is approximately the same as observed. Of course, I can’t confirm this, I just mean it 🙂
Turning radius in the track, calculations
Now let's move on to setting the route. This season (2017) we set 9.5 meters (or slightly less than " 6 skis", ski in a straight line 1.64 m) between the gates. I’ll see what the “divorce” of the track should be so that the skis can pass it 🙂 With a track corridor width of 3 meters, the minimum radius of two conjugated arcs (see the figure on the left) is 7.5 meters, which corresponds to an edge angle of 52.5 degrees. In principle, it is believed that such a trajectory is not the fastest, it is better to “raise” it a little, so that you approach the pole a little more across the slope, and not straight down as in the figure. This will increase the radius and increase the width of the path corridor. But I won't do it here.
Mathematically corridor ( W) can vary from zero (the radius is infinity) to the distance between the gates ( L). In the corridor width range, the trajectory can be described by conjugated circles. This limit corresponds to an angle of 45 degrees between the straight line connecting the gate and the downward direction. In our case, this width is 6.7 meters, the corresponding radius is 3.4 meters, which corresponds to an edge angle of 74 degrees. The general formula for the radius of the trajectory in this range is: . Since the ski has a maximum radius of 12.3 meters, this imposes a restriction on the minimum trail opening equal to 1.84 meters (the corresponding edge angle is “equal” to zero 🙂 That is, if the route corridor is less than 1.84 meters, then a straight line must be inserted into the trajectory vertical section.And if the route corridor is more than 6.7 meters, then a straight horizontal section must be inserted into the trajectory, and the turning radius on the round parts of the trajectory must be equal to half the downward slope component of the distance between the gates.
In the range of the route corridor width from 1.84 to 6.7 meters, the calculated trajectory radii and the corresponding edge angles look like this:
Unfortunately, when setting the tracks in the last season (2017), the distance between the gates was measured strictly with skis, and the transverse “divorce” was set “by eye”. Therefore, I can’t say for sure about the width of the corridor of our tracks. I won't do it again 🙂
Vitaly Sizov sets the track. Photo — Sergey Ezhov Vitaly SizovI turned to Vitaly Sizov, he sets the width of the route corridor strictly, measures it with skis. He puts a stick, then the next one, then moves horizontally from this stick until he is exactly under the top stick. And considers skis. Not for every milestone, but for verification. Vitaly reported the following parameters: "If the distance between the poles is 6 skis, then the horizontal distance is 1.5 skis - open, 2 skis - normal, 2.5 skis - closed."
If we translate this into the width of the corridor in meters and into the corresponding calculated edge angle, then it turns out like this:
- "Open", width = 2.5 meters, turning radius = 9.0 m, edge angle = 43 degrees;
- “Normal”, track width = 3.3 meters, turning radius = 6.8 meters, edge angle = 56 degrees;
- “Closed”, track width = 4.1 meters, turning radius = 5.5 meters, edge angle = 63 degrees.
Alexander Mistryukov said that he puts it “by eye”, on a steep slope of about 5 meters (R = 4.5 m, angle = 68.5 degrees).
In general, it turns out that in order to “cut through” the slalom track, you need to master skiing with an edge angle of about 60 degrees. It should also be taken into account that in the calculations the edge-over occurs instantaneously. In fact, of course, there is no such thing, which is probably why the shape of the arc in the track is not a circle, but a “comma”, and you need to turn over more. But also the trajectory of a slightly larger radius, since it is “wider and higher”. Therefore, most likely, in general, the calculated edge angle and the real one approximately coincide.
The edge angle of 45 degrees, which I mentioned above as typical for a carved arc in free skating, is generally “nothing”. This corresponds to a track corridor of only 2.6 meters. And it’s a shame that if you don’t turn the skis at all, then the corridor of the track is 1.84 meters. That is, only 76 cm of additional width between the poles corresponds to the transition from flat skiing to a 45-degree angle. It turns out that the ability to turn skis to an angle of 45 degrees is not much different from not being able to turn them at all 🙁
Only geometry was taken into account. The steepness of the slope, overloads, grip with the slope were not taken into account. Nevertheless, indeed, slalom skis can “pass the slalom track themselves” 🙂 You just need to be able to turn them powerfully and not “go off the rails”.
Conclusion
Slalom skis do have their own “favorite” arc, where they can cut through a typical (in the amateur sense) slalom course. But without the ability to cut arcs with edge angles from 60 degrees, you won’t get close to this favorite arc 🙂