Patent application title: ALPINE SKI
Bertrand Krafft (Brison Saint-Innocent, FR)
IPC8 Class: AA63C504FI
Class name: Runner type skis with special shape, contour, or groove
Publication date: 2011-05-26
Patent application number: 20110121542
A ski adapted for the practice of alpine skiing includes a front portion,
a rear portion, and a central portion, the central portion being adapted
to receive an assembly for binding a boot to the ski, which is inserted
between the front portion and the rear portion. The front portion
includes a maximum width having a value ranging between 135 mm and 165
mm, and the difference between the maximum width value of the front
portion and the maximum width value of the rear portion is greater than
25 mm and less than 55 mm. The rear portion can include a maximum width
value ranging between 90 mm and 130 mm, and the central portion can
include a smaller width value ranging between 60 mm and 130 mm.
1. A ski structured and arranged for the practice of alpine skiing, said
ski comprising: a front portion; a rear portion; a central portion
structured and arranged to receive an assembly for binding a boot to the
ski, such assembly to be mounted to the ski between the front portion and
the rear portion; the front portion of the ski comprises a portion of
greater width, including a maximum width value (S) ranging between 135 mm
and 165 mm; a difference between the maximum width value (S) of the front
portion and a maximum width value (T) of the rear portion is greater than
2. A ski according to claim 1, wherein: the central portion comprises a line of smallest width and a marking of the boot center (MC) corresponding to a zone in which the binding assembly is to be centered; a distance (LC) separating the line of smallest width and the marking of the boot center is greater than 150 mm.
3. A ski according to claim 1, wherein: the rear portion comprises a portion of greater width, including the maximum width value (T) ranging between 90 mm and 130 mm.
4. A ski according to claim 1, wherein: a smallest width of the central portion (4) has a value (C) ranging between 60 mm and 130 mm.
5. A ski according to claim 1, wherein: the difference between the maximum width value (S) and the maximum width value (T) is greater than 32 mm.
6. A ski according to claim 1, wherein: the difference between the maximum width value (S) and the maximum width value (T) ranges between 32 mm and 55 mm.
7. A ski according to claim 1, wherein: the maximum width value (S) ranges between 140 mm and 160 mm.
8. A ski according to claim 2, wherein: the distance (LC) is greater than 180 mm.
9. A ski according to claim 1, wherein: the shovel has a length (Ls) ranging between 150 and 320 mm.
10. A ski according to claim 9, wherein: the shovel has a length (Ls) ranging between 160 and 300 mm.
11. A ski according to claim 1, wherein: a width (P) of the ski, measured at a distance of 30 mm from a front end of the ski, is less than 60% of the maximum width value (S) of the front portion: P<0.6.times.S.
12. A ski according to claim 11, wherein: a width (P) of the ski, measured at a distance of 30 mm from a front end of the ski, is less than 50% of the maximum width value (S) of the front portion: P<0.5.times.S.
13. A ski according to claim 4, wherein: the line of the smallest width (C) of the central portion and the line of the maximum width value (T) of the rear portion are merged.
14. A ski according to claim 4, wherein: a distance (LB) separating the maximum width value (T) of the rear portion and the smallest width value (C) of the central portion is zero.
CROSS-REFERENCE TO RELATED APPLICATION
 The instant application is based upon the French priority Patent Application No. 09.05587, filed Nov. 20, 2009, the disclosure of which is hereby incorporated by reference thereto, and the priority of which is hereby claimed under 35 U.S.C. §119.
 1. Field of the Invention
 The invention relates to gliding apparatuses, in particular skis adapted for the practice of alpine skiing.
 2. Background Information
 A pair of alpine skis is comprised of two boards that are substantially identical or at least symmetrical with respect to one another. One of the basic techniques of skiing requires the skier to maintain his/her body in a plane perpendicular to the ground in order to move along a straight line, or to tilt his/her body toward the inside of the turn in order to turn. This has a direct consequence on the positioning of the skis with respect to the ground. When the skier moves along a straight line, the skis are flat on the ground, resting on the gliding surface of the bottom layer, referred to as the sole. When turning, the skier inclines his/her skis with respect to the ground. In this case, It is the lower outer corners; commonly referred to as the running edges (or bottom edges) which come into contact with the ground or snow. When viewed from above, the contour of the running edges is called the sidecut. It is to be understood from the preceding that, among the various characteristics that constitute a ski, the geometry of the sidecuts plays a determining role in the behavior of the ski. In particular, the sidecuts define the type of steering to be applied by the skier. The running edges are in particular defined as being the lower edges of the ski that are located between the widest zone of the ski at the front of the ski and the widest zone of the ski at the rear.
 The methods of manufacture of alpine skis, as well as their geometrical and structural dimensions, have evolved since the beginning of alpine skiing. New developments sometimes have been driven by changes in the practice of the sport and/or sometimes in the manufacturing processes.
 Skis sold until the 1980s were relatively long, straight, and narrow. The sidecuts had very large radii, typically greater than 30 meters (m). The maximum width in the front portion of such skis and the maximum width in the rear portion of such skis had substantially the same values. Furthermore, the zone of the ski with minimal width, also called the narrow point, or waist, was in the middle of the ski, i.e., in the area of the boot binding zone. Such skis were suitable for use on the trails of that time and they were particularly adapted to the skiing techniques used at the time. Each turn required the skier to reduce the pressure exerted on the skis, enabling the skier to turn, i.e., steer, the skis. To a certain extent, such skis remain well-adapted to skiing at high speed, in a straight line and on-piste. Standing apart free from the shape of skis sold mainly until the 1980s, some independent inventors proposed different shapes, which were however unsatisfactory. An example of these various shapes is disclosed in the patent document CH 503 501, which explains that the reduction in the width of the heel portion, up to a value of 5 centimeters (cm), was compensated for by the widening of a groove in the sole. Such geometry lacks versatility, in particular due to the small width in the area of the heel. Moreover, making a groove with a variable width would render the ski particularly expensive to manufacture.
 In the early 1990s, the patent document DE 41 12 950 discloses a new shaped ski having an objective of improving the behavior of the ski when turning and to enable faster direction changes. This shaped ski is characterized in that the concave portion is reduced lengthwise and has a reduced radius compared to what was prevalent at the time. This concave portion is substantially centered longitudinally in the middle of the ski. The ski sidecuts are constituted by rectilinear portions below and above the reduced concave portion. The rectilinear portions of the sidecut, the length of which ranges between 10 and 20 cm, connect the concave portion to the shovel, on the one hand, and to the heel, on the other hand. Such geometry produces a ski whose turning ability can be improved, but whose behavior is not fluid.
 Beginning in the 1990s, the sidecuts became deeper and the radii shorter. The skiing technique also changed so as to reduce, even eliminate, the need to lighten the pressure when turning. These skis are particularly adapted to practice on a packed ski trail. The patent application EP 579 865, for example, describes such a ski, in which the minimal width is in the area of the bindings, in the central portion of the ski, and is equal to 63 millimeters (mm), while the width at the shovel, i.e., the front portion of the ski, and the width at the heel, i.e., the rear portion of the ski, are equal to 110 mm and 100 mm, respectively. Skis of this type made it possible to bring about a new skiing technique, referred to as carving, which involves cutting into snow through the turns. To promote ski carving, it is important to have very deep sidecuts, and consequently shorter radii. When these skis appeared on the market, they were termed parabolic skis because the geometry of their sidecut was similar to a parabolic shape; the maximum width in the area of the shovel and that in the area of the heel were relatively substantial and substantially the same, within 10 or 20 mm as in the example mentioned above, whereas the minimal width in the area of the central portion was much smaller. Currently available skis are mainly based on this type of geometry. Skis with very deep sidecuts have a satisfactory behavior on-piste but a very poor behavior off-piste. Indeed, the sidecuts with very short radii cause the ski to engage in curves too easily in soft snow. It is therefore very difficult to ski in a straight line.
 Skis also became shorter and thicker, as shown in U.S. Pat. No. 5,603,522. This skis disclosed in this document have a length less than 1730 mm, a shovel having a width ranging between 110 and 120 mm, a waist having a width ranging between 82 to 99 mm, and a heel having a width ranging between 105 and 115 mm, it being necessary to maintain the variation between the width of the shovel and that of the heel between 4 and 12 mm. The objective leading to the manufacture of such skis was to optimize torsional stiffness by combining a relatively great width with a relatively small length. As a result of this preconceived purpose, these skis are not very versatile. It is difficult to design a ski with this geometry, which can behave optimally on-piste and off-piste. It is also difficult to design a ski according to this geometry, which can be adapted to various skiers having various technical skills and goals (beginners, leisure, competition). Shortening the length of the skis did however not redefine the direction which was set during the 1990's for the parabolic skis. In fact, these skis still have the characteristic whereby the zone of the ski with minimal width is in the center of the ski, in the area of the ski boot center.
 Freeride, a primarily off-piste skiing technique in virgin snow, was introduced in the 2000s, and specific skis have been developed by manufacturers. These skis are very wide and have waist widths that can reach 140 mm. Of course, these skis are not versatile at all; they are very difficult to operate on-piste and are intended for experienced skiers. Indeed, steering a ski that is very wide in its central portion on-piste requires a substantial muscular effort and is almost impossible to use for a beginner or a skier with little skiing experience. Such skis are described, for example, in U.S. Patent Application Publication No. 2008/00042400.
 One of the characteristics of the skis adapted for the discipline, or practice, of freeride is that their shovels are substantially longer and wider than that of the skis adapted for on-piste practice. As defined in the ISO Standard 6289, the ski shovel is the portion that is turned upward to enable the ski to ride easily over obstacles. According to the standard, the length of the shovel is defined by the distance separating the tip of the ski from the front contact line (the front limit of the contact zone of the bottom surface of the ski on a planar surface). One can choose to determine this length by measuring the projection on a planar surface, this being the projected length, or by measuring the nominal length, this being the developed length. In the following description, reference to length will refer to the developed length. Furthermore, for practical reasons, the term shovel length "Ls", as used in the following description, means the measurement taken between the end of the ski and the line of greatest width at the shovel, and not the "end-to-contact line" distance, as provided in the standard. The portion of the ski referred to as the "shovel" in the ISO Standard 6289 will be called the "raised zone" of the ski. The shovel and the raised zone merge more or less along the distance between the front contact line and the line of greatest width.
 For a ski adapted for off-piste practice, or use, and in deep snow, it seems advantageous to have a high, long, and wide shovel. However, these characteristics turn into disadvantages when the skier wishes to use the skis on-piste. Indeed, the mass of the portion of the ski raised off the snow is increased with shovels of this type, which also tend to cause vibrations in the ski and to weigh it down.
 The invention provides an alpine ski that has an optimal behavior on-piste as well as off-piste.
 In addition, the ski of the invention provides, for a skier having little practice and/or a weak muscular force, with the ability to ski under any circumstances, on any type of snow, whether on-piste or off-piste.
 Further, the invention provides a new family of skis enabling a new technique for the practice of alpine skiing.
 Still further, the invention provides a new family of skis that include a plurality of pairs of skis, all of which have an optimal behavior on-piste and off-piste, but which distinguish over one another by a greater suitability for skiing on-piste or off-piste.
 A ski according to the invention is provided with a geometry that combines advantages of skis with deep sidecuts and those of skis with broad sidecuts.
 In addition, a ski according to the invention has a shovel that provides the ski with an improved behavior in powder snow.
 A ski according to the invention includes a front end that does not vibrate during use on-piste.
 Further, the invention provides a ski that offers definitely new behavioral characteristics, in that, e.g., the front portion of the ski (located ahead of the boot) and the rear portion of the ski (located behind the boot) each has a different behavior.
 To these ends, a ski according to the invention is provided that is adapted for the practice of alpine skiing, the ski including a front portion, a rear portion, and a central portion, the latter adapted to receive a binding assembly for binding a boot to the ski, the binding assembly being inserted between the front portion and the rear portion; the front portion of the ski includes a portion of relatively greater width, which includes, along its length, a maximum width value "S", ranging between 135 mm and 165 mm, and in which the difference "Δt" (delta-t) between the maximum width value "S" of the front portion and the maximum width value "T" of the rear portion is greater than 25 mm.
 According to advantageous but non-limiting aspects of the invention, a ski according to the invention includes a front portion, a rear portion, and a central portion; and it can incorporate one or more of the following features, taken in any technically acceptable combination:  the rear portion includes a portion of greater width having a value "T" ranging between 90 mm and 130 mm;  the central portion includes a portion of smaller width having a value "C" ranging between 60 mm and 130 mm;  the difference "Δt" (delta-t) between the value "S" and the value "T" can range between 32 mm and 55 mm;  the value "S" ranges between 140 and 160 mm;  the shovel has a length "Ls" ranging between 150 and 320 mm, or, in an alternative embodiment, between 160 and 300 mm;  the value "P" corresponding to the width of the ski, measured at a distance of 30 mm from the front end of the ski, is less than 60% of the maximum width value of the front portion: P<0.6×S, or, in an alternative embodiment, less than 50% of the maximum width value of the front portion: P<0.5×S;  the distance separating the boot center MC from the line of smaller width C is greater than 150 mm, or, in an alternative embodiment, greater than 180 mm;  the distance LB separating the line of smaller width C from the line of greater width of the rear portion T is null.
BRIEF DESCRIPTION OF DRAWINGS
 Other characteristics and advantages of the invention will be better understood from the description that follows, with reference to the annexed drawings illustrating, by way of non-limiting embodiments, how the invention can be embodied, and in which:
 FIG. 1 is a top view of a ski according to a first embodiment of the invention;
 FIGS. 1a and 1b are detailed views of FIG. 1;
 FIG. 2 is a side view of the ski shown in FIG. 1;
 FIG. 2a is a detailed view of FIG. 2;
 FIG. 3 is a top view of a ski according to a second embodiment of the invention;
 FIG. 3a is a detailed view of FIG. 3;
 FIG. 4 is a top view of a ski according to a third embodiment of the invention;
 FIG. 5 is a top view of a ski according to a fourth embodiment of the invention;
 FIG. 6 is a top view of a ski according to a fifth embodiment of the invention; and
 FIG. 7 is a top view of a ski according to a sixth embodiment of the invention.
 FIG. 1 is a top view illustrating only one of the skis of a pair adapted for the practice of alpine skiing.
 According to a known general configuration, the illustrated ski includes a gliding sole having a bottom surface, or running surface, adapted to be in contact with snow, an inner structure, and a top portion. As described below, the ski of FIG. 1 features definitively new sidecuts.
 The top of the central portion 4 of the ski receives the safety bindings 5 which retain the ski boot (not shown) of the user on the ski. The smallest width of the central portion 4 of the ski, referred to as the waist, has a value C equal to 88 mm in the ski of the illustrated embodiment. This is a relatively large value compared to the skis designed up to the early 1990s. However, this value is not as great as the widths currently recommended for skis intended for use in powder snow. Such a width, ranging between 60 and 120 mm, or 70-100 mm in a more limited range, provides the ski with great versatility of use and makes it available to a larger number of users, i.e., from beginners to experienced skiers.
 FIG. 1b illustrates a detailed top view of the central portion of the ski, showing the respective positioning of the two characteristic lines of the central portion of the ski, namely, the boot center and the narrow point. The boot center line is a marking affixed on the ski by the manufacturer to indicate the recommended positioning of the ski bindings, such that the boot, once bound on the ski, is centered on the boot center line. Unlike the skis of the prior art, the transverse line C at the smallest width of the central portion, commonly called the ski narrow point, is set back with respect to the boot center line (MC) by a value greater than 150 mm. In the ski illustrated in FIG. 1, the distance LC separating the narrow point and the boot center line is equal to 271 mm.
 The rear portion 3 of the ski, also referred to as the heel, has a zone of greater width, including a value T ranging between 90 and 110 mm. Such a width enables support to be taken relatively easily at the end of a turn, without it being necessary to exert very strong supporting forces on the running edges. In the example shown in FIG. 1, the value T is equal to 100 mm.
 The heel illustrated in FIG. 1 has a pointed shape. This shape is only one of the multiple shapes that the heel can take, and it is not to be considered as limiting the scope of the invention.
 According to the invention, the front portion of the ski comprises a front portion 2, whose maximum width, having a value S, is much greater than the maximum width, having a value T, of the heel portion.
 Tests on various sidecut geometries have shown that the effects sought by the invention can be obtained if the difference "Δt" (delta-t) between the maximum width value S of the front portion 2 and the maximum width value T of the rear portion 3 is greater than 25 mm. It has also been shown that these effects are amplified so as to mark a significant behavioral difference with known skis of the prior art, as soon as the value Δt is greater than 32 mm. Indeed, with a value Δt equal to or greater than 32 mm, the difference in behavior generated by the geometry of the front portion and rear portion of the ski becomes more significant. For reasons related to weight and space requirement, the length of the shovel is limited to a value of 190 mm. In a particular embodiment within the scope of the invention, the maximum width of the shovel S is also limited as a function of the width of the rear portion T, such that the value Δt remains less than 60 mm, or, in an alternative embodiment, less than 55 mm.
 In the example shown in FIG. 1, the front portion 2 has a maximum width S that is equal to 150 mm; the difference Δt is equal to 50 mm.
 The ski illustrated in FIG. 1 thus has a shovel of very substantial width, i.e., a width that is on the same order as the shovel widths of currently known skis, but which is exclusively provided for the practice of freeride. In fact, the current freeride skis are much too wide to enable easy steering on a packed trail. Due to its wide shovel, the ski 1 has a good behavior in deep snow. Moreover, it is much easier to control this ski on-piste than a freeride ski. This is a particularly versatile ski whose behavior on-piste and off-piste is optimized, in particular due to a minimal width being equal to 88 mm in the central portion.
 A versatile ski, such as shown in FIG. 1, seeks to limit the mass of the shovel that is raised from the snow while preserving an adequate length for the shovel. To this end, pointed shovels whose lines of greatest width in the front portion are at a relatively low height are particularly advantageous, as explained below.
 FIG. 1a shows the "pointed" characteristic of the contour of the front portion 2 of the ski 1. This pointed characteristic is shown by the measurement of the ski width in the vicinity of the ski front end, i.e., the tip 6. This measurement, designated by the reference character "P", is taken at a distance of 30 mm (developed length) from the tip 6 of the ski 1. In this example, the value of P is 55 mm.
 The shovel is considered to have a pointed contour insofar as the value "P" is less than or equal to half (50%) of the maximum width of the front portion 2, i.e., the value "S" (P≦0.5×S).
 In advantageous embodiments, a pointed shovel is relatively long. In the context of the invention, the length "Ls" of shovel is selected to be greater than 150 mm. The skis of the invention yielding the best performances are those that have a shovel length ranging between 150 and 320 mm.
 To improve the behavioral versatility of the skis according to the invention, pointed shovels (P≦0.5×S) are used. However, skis according to the invention whose shovels are moderately pointed, i.e., those having a value "P" less than or equal to 60% of the value "S", yield satisfactory results. Furthermore, skis having round shovels are also within the scope of the invention.
 FIG. 2 is a side view of the ski 1 of FIG. 1. The ski rests on a planar surface 9, in the area of two lines, i.e., the front contact line 7 and the rear contact line 8. The length Ls of the shovel, measured between the line of greatest width and the tip 6 of the ski, is equal to 256 mm in the illustrated embodiment.
 The front contact line 7 is located near the line 10 of greatest width of the ski shovel. As shown in FIG. 2a, this proximity translates into the ski sole being at a height "Hs", said height being less than 10 mm, e.g., in the area of the line of greatest width.
 FIG. 1 illustrates a ski having an overall length equal to 1900 mm. This length is not limiting to the scope of the invention. Indeed, the particular geometry of the invention can be easily applied to skis that are longer or shorter than 1900 mm.
 FIG. 3 shows a second embodiment of the invention. As in the embodiment described above, this ski is designed for a multipurpose use on-piste and off-piste, with a slight predisposition for ski carving, and for use in fresh snow. In the area of the rear portion, the greatest width of the ski, having the value "T", is equal to 105 mm; the minimum width of the central portion 4, having the value "C", is equal to 80 mm; and the greatest width of the shovel, having the value "S", is equal to 140 mm.
 A ski is thus obtained, whose sidecuts are sufficiently deep, the radius of the sidecut being equal to approximately 11 m. The difference between the shovel width and the heel width, i.e., the value "Δt", is equal to 35 mm.
 The shovel is very long, the value "Ls" being equal to 300 mm, and very pointed, the value "P" being equal to 42 mm, which corresponds to 30% of the greatest shovel width.
 FIG. 3a is a detailed view of the ski shown in FIG. 3, which makes it possible to visualize the relationship between the various characteristic lines of the rear half-length of the ski. The boot center line MC is positioned at a distance LA from the line of greatest width T of the heel. Conventionally, the length LA corresponds to a certain percentage of the overall length of the sidecut. The line of smallest width of the ski in the central portion, also called the narrow point and designated by the reference character "C" in the drawing figures, is located between the lines MC and T. According to the invention, the distance LC separating the lines C and MC is greater than 150 mm. In other words, the narrow point is behind the boot, when the boot is bound on the ski.
 FIG. 4 shows a third embodiment of the invention, for which the values S, C and T are equal to 160, 103, and 117 mm, respectively. The shovel is relatively long, the value "Ls" being equal to 300 mm. This ski is particularly adapted for off-piste practice; and it is designated as a freeride ski with reference to one of the categories currently used by manufacturers to brand their products.
 However, due to a particularly substantial difference between the width of the shovel and that of the heel, the value "Δt" being equal to 43 mm, the ski has a notably improved versatility when compared to the typical skis in the freeride category.
 The front portion 2 is also characterized by its "pointed" feature. Indeed, the width P, measured at a distance of 30 mm from the tip 6, is equal to 53 mm, i.e., corresponding to approximately 34% of the width value "S" of the shovel.
 FIG. 5 shows a fourth embodiment of the invention, for which the values S, C, and T are equal to 140, 68, and 90 mm, respectively. The shovel has a length "Ls" of 190 mm and a pointed shape with a value "P" equal to 57 mm (40% of the value S). This ski is particularly adapted for on-piste practice.
 However, due to a particularly substantial difference between the width of the shovel and that of the heel, the value "Δt" being equal to 50 mm, the ski has a notably improved versatility compared to the skis that are typically dimensioned for on-piste practice. In particular, with such a ski, the user can occasionally switch to a different practice of skiing and leave the trail. Such a ski makes freeride practice more easily accessible to beginners or skiers having little experience.
 Table 1 below recapitulates the geometrical data of a complete line of skis according to the invention. These skis are characterized by an improved versatility compared to the skis known to date, while each having a preferred field of practice.
 The line of skis shown in Table 1 includes eighteen skis each having a different geometry, but all of which share the innovative characteristics of the invention. The overall length of the skis is not specified in this table. Each ski included in this line was developed with an average length ranging between 2000 and 1600 mm. In order to assemble this inclusive offering, the manufacturer presents each of the skis in various sizes to adapt each geometry to the weight and size of the users.
 The first three skis in the table, which include the ski shown in FIG. 5, are skis that yield their best performance on-piste due to a relatively small width at the waist. However, when the skier practices off-piste with one of these skis, he/she will benefit from a good lift due to a long and wide shovel. In the case in which the ski has a pointed shovel, as in FIG. 5, these skis are completely adapted for speed and, for example, for downhill and giant slalom (GS) competitions.
 The eight skis at the bottom of the table are designed mainly for off-piste use. However, due to a minimal width in the central portion not exceeding 130 mm, and particularly not exceeding 120 mm, these skis remain very easy to control on-piste. On-piste, these skis do not require any more steering effort from the user than skis especially designed for on-piste practice. Also, the choice of a pointed shovel, as for the ski shown in FIG. 4, further increases the versatility of use of these skis.
 In the middle of the table, eight skis, in which the ratio of the on-piste aptitude to the off-piste aptitude ranges between 70/30 and 30/70, are designed for on-piste and off-piste practices. The skis shown in FIGS. 1 and 3 are examples of such multipurpose skis.
TABLE-US-00001 TABLE 1 ##STR00001##
 As described above, one of the aspects of the invention is related to the fact that the narrow point is set back with respect to the boot center by a value greater than 150 mm, or, in particular embodiments, greater than 180 mm. Table 2 compiles the values of four different ski geometries sharing the same shovel and heel widths, but whose narrow point is in different positions.
TABLE-US-00002 TABLE 2 S C T Δt LB LC 160 106 125 35 515 177 160 118 125 35 400 290 160 123 125 35 261 431 (FIG. 6) 160 125 125 35 0 692 (FIG. 7)
 The first two lines in the table correspond to ski geometries that are well-adapted for off-piste practice, and in which the position of the narrow point with respect to the center boot, at 177 and 290 mm, respectively, is such that these geometries provide the ski with good directional mobility.
 The third line in the table corresponds to a geometry, an exemplary ski of which is shown in FIG. 6. As shown, the line of the narrow point is far set back. The distance separating the narrow point from the line of greatest width of the heel corresponds substantially to one third (1/3) of the distance separating the line of greatest width of the heel from the boot center. The setback position of the narrow point improves the stability of the ski at high speed and, due to a difference in the shovel/heel width being equal to 35 mm, this ski maintains a good versatility.
 FIG. 7 shows a ski in which the shovel/heel difference is also equal to 35 mm, but whose narrow point is set back to the maximum, i.e., up to the area of the greatest width of the heel. In this geometry, the line of the narrow point C and the line of greatest width T of the heel merge. The complete sidecuts of the ski connect the narrow point C to the line of greatest width S of the shovel. The sidecut is a curved line whose mean radius of curvature can be greater than that of the other embodiments of the invention. For example, the mean radius of the sidecut can exceed 30 m, even 50 m, whereby reference is made to an extended sidecut.
 The ski shown in FIG. 7 offers practice versatility, in particular for the practice of freeride, associated with excellent directional stability.
 This ski is particularly adapted for the latest category among off-piste practices, i.e., the "Big Mountain". The practice known as "Big Mountain" involves going downhill at very high speed on very sloped mountainsides and along trajectories having large radii of curvature.
 The invention is not limited to the embodiments that have just been described; and it includes all of the technical equivalents that are within the scope of the claims that follow.
 In addition, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.
Patent applications by Bertrand Krafft, Brison Saint-Innocent FR
Patent applications by SALOMON S.A.S.
Patent applications in class With special shape, contour, or groove
Patent applications in all subclasses With special shape, contour, or groove