Ski binding
Encyclopedia
Ski boot
Ski boots are specialized footwear that are used in skiing to provide a way to attach the skier to skis using ski bindings. This ski-boot-binding combination is used to effectively transmit control inputs from the skier to the snow....
to the ski
Ski
A ski is a long, flat device worn on the foot, usually attached through a boot, designed to help the wearer slide smoothly over snow. Originally intended as an aid to travel in snowy regions, they are now mainly used for recreational and sporting purposes...
. There are different types of bindings for different types of skiing
Skiing
Skiing is a recreational activity using skis as equipment for traveling over snow. Skis are used in conjunction with boots that connect to the ski with use of a binding....
.
Universal designs
In the earliest days of skiing, the skis were used in a fashion somewhat similar to snowshoeSnowshoe
A snowshoe is footwear for walking over the snow. Snowshoes work by distributing the weight of the person over a larger area so that the person's foot does not sink completely into the snow, a quality called "flotation"....
s, roughly a walking motion, although they were slid over the snow instead of lifted with each stride. During this era, the binding was also similar to those of a contemporary snowshoe, generally consisting of a leather strap fastened over the toe of the boot.
During the 1800's, skiing evolved into a sport and great advances in technique and equipment design followed. Generally the skiing motion was much closer to skating
Ice skating
Ice skating is moving on ice by using ice skates. It can be done for a variety of reasons, including leisure, traveling, and various sports. Ice skating occurs both on specially prepared indoor and outdoor tracks, as well as on naturally occurring bodies of frozen water, such as lakes and...
, using long gliding strides. This technique required bindings that followed the skier's foot through a wider range of motion, but loosening the toe strap simply made it fall off. To address this, a second strap was added that looped from the toe around the heel of the boot, pulling it forward into the toe strap. Over time, the toe strap evolved into a metal cup that provided much greater grip, and the heel strap was replaced by metal cables and springs. During downhill runs, the skier could clip the cable under small fingers near the heel of the boot, locking it down and providing better control. When the downhill portion ended, they could be unclipped to allow the normal striding motion.
It was not until the 1930s that the techniques for alpine and cross country skiing started to separate in earnest. The introduction of ski lift
Ski lift
The term ski lift generally refers to any transport device that carries skiers up a hill. A ski lift may fall into one of the following three main classes:-Lift systems and networks:...
s propelled this evolution. This led to the desire for bindings that would release in the case of an accident, which was more likely to cause injury during the higher speeds of a downhill decent. At the same time, the need to unclip the binding for the cross-country portion was eliminated.
Cable bindings remained in use for some time for cross-country, and a limited selection are still available today.
Alpine
Alpine skiing
Alpine skiing is the sport of sliding down snow-covered hills on skis with fixed-heel bindings. Alpine skiing can be contrasted with skiing using free-heel bindings: Ski mountaineering and nordic skiing – such as cross-country; ski jumping; and Telemark. In competitive alpine skiing races four...
work by fixing the ski boot to the ski at the toe and heel. The binding attaches the boot to the ski, but to reduce injury also allows the boot to release in case of a fall. Generally, the toe piece is designed to allow the boot to rotate to the sides, while the heel piece rotates up. In modern bindings a wide variety of motions is available from each binding.
The boot is released by the binding if a certain amount of torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....
is applied (usually created by the weight of a falling skier). The amount of torque required to release the boot is adjusted by turning a screw on the toe and heel piece. This is called (colloquially) the DIN
Din
DIN or Din or din can have several meanings:* A din is a loud noise.* Dīn, an Arabic term meaning "religion" or "way of life".* Din is one of the ten aspects of the Ein Sof in Kabbalah ....
setting, because the standards for Alpine ski binding settings are issued by Deutsches Institut für Normung
Deutsches Institut für Normung
is the German national organization for standardization and is that country's ISO member body. DIN is a Registered German Association headquartered in Berlin...
. The correct DIN setting is based on height, weight, ski boot sole length, the skiing style of the skier (cautious, average, or aggressive) and, age (if the skier is younger than 10 years old, or 50 years old or older).
Normally, torque itself does not cause injury, not until a natural limit of the human skeleton is reached. For instance, a very strong vertical torque, twisting the knee, will not cause damage unless the knee is forced to travel a certain angle. Some bindings move relatively short distances before releasing, leading to the possibly of "pre-release", where the ski releases long before the motion could have caused damage. Bindings with longer "float" may hold on during events that require those with shorter motion would require higher DIN settings.
Bindings may be sold alone to be mounted to "flat" skis or can be integrated systems. Integrated systems have declined in popularity due primarily to their higher weight and difficulty of adjusting the balance of a skier since cants and shims are difficult or impossible to use. Some racing skis have plates on them which allow a binding to be attached and afford the possibility of changing the balance through cants and shims.
Alpine ski bindings employ the use of a snow brake to prevent the ski from moving while it is not attached to a boot. Snow brakes work by the use of a sprung square 'C' shape, typically made of metal, which makes contact with the snow. When a ski boot is put in the ski binding, the brake pivots under the downward pressure and runs parallel with the ski allowing free movement. When the boot comes out of the ski, the brakes spring out perpendicular to the ski and stop the ski from sliding.
Cross country
There are three common Nordic binding systems:- NNN (New Nordic Norm, marketed by RottefellaRottefellaRottefella is a Norwegian ski binding manufacturer.-Rottefella/Fischer Partnership:Taking effect beginning of the 2007-2008, Rottefella will be the official bindings of Fischer Skis boots. Presently, Fischer boots use the Salomon Nordic System Rottefella is a manufacturer of NNN bindings...
), where a bar in the toe of the shoe is hooked into a catch in the binding. Also exists in the more rugged BC (Back Country) variant. Two small ridges run along the binding, corresponding with slits in the boot. There have been several versions of NNN, and the first NNN version is not compatible with current designs. - NIS (Nordic Integrated System) is the latest incarnation of NNN, unveiled by RossignolSkis RossignolSkis Rossignol S.A., or simply Rossignol, is a French manufacturer of alpine, snowboard, and Nordic equipment, as well as related outerwear and accessories, located in Isère, France. Rossignol was one of the first companies to produce plastic skis. The company also owns the brand Dynastar as well...
, MadshusMadshusMadshus is an Norwegian ski and ski-equipment manufacturer, located at Biri in Gjøvik. The company produces cross-country skis and ski-boots.- History :...
, Rottefella, and AlpinaAlpina ŽiriAlpina Company was founded in 1948 after several private shoemaking workshops with long tradition joined together in the town of Žiri, Slovenija....
in January 2005; The new system features integrated binding plate on the top of the ski to which the bindings attach, allowing easy installation of bindings and even adjusting them on-the-fly depending on weather and snow conditions. NIS bindings and boots are fully compatible with NNN boots and bindings, and NIS skis allow installation of non-NIS bindings. In 2007, FischerFischer- Origin and meaning :The German language name is derived from the profession of the fisherman. The name Fischer is the fourth most common German surname.- Variants:* Fisher * Fischler* Vischer* Fischers* Fischl* Fischel* Fischle)...
abandoned SNS and entirely switched to NIS; at the same time, AtomicAtomic SkisAtomic is an Austrian company which manufactures and sells skiing equipment .-Background:...
abandoned NNN and switched to SNS.
- SNS (Salomon Nordic System; marketed by SalomonSalomon GroupThe Salomon Group is a sports equipment manufacturing company that originated in Annecy, France. The company was started in 1947 by François Salomon and his wife and son. In 1997 it became part of the Adidas group. On 2 May 2005, Adidas-Salomon announced that it had agreed to sell the Salomon...
) looks very similar to NNN binding, except it has one large ridge and the bar is narrower. Three variants exist: Profil, the standard model; Pilot, specific for either skate-style or classic-style cross-country skiing, and the "X-Adventure" variant for backcountry skiing. While Pilot skate boots can be used with a normal Profil binding, Profil boots cannot be used with Pilot skate setups. Because of its ease of use it is quite common, though in some places NNN equipment (broadly comparable in terms of cost and performance) is easier to come by and hence used more. Previous SNS systems exist with a loop protruding from the front of the boot rather than a bar flush with the front, and these are obsolete and no longer available. Current providers of SNS boots and bindings include Salomon, AtomicAtomic SkisAtomic is an Austrian company which manufactures and sells skiing equipment .-Background:...
(both belonging to Amer SportsAmer SportsAmer Sports Oyj is the largest manufacturer of sporting equipment in the world. Established in 1950, the company is based in Helsinki, Finland...
group), and Hartjes; Fischer formerly supplied SNS boots but entirely switched to NIS in 2007. - 75 mm (Rottefella, Nordic Norm, 3-pin) This is the original, classic system found on cross country skis, invented by Bror WithBror WithBror With , born in Norway's capital Kristiania, was a mechanical engineer, inventor and industrialist. He graduated in 1925 from the Norwegian Institute of Technology....
. These bindings, once the standard, are no longer as popular as they were but still hold a significant share of the market for mid-weight touring setups with relatively heavy boots, as typically used for hut-to-hut touring in Norway. In this system the binding has three small pins that stick up. The toe of the boot has three holes that line up with the pins. The boot is then clamped down by a bail. Despite the decreasing use of the 3 pin "rat trap" ("rottefella" in Norwegian) binding in lighter cross country, the characteristic "duckbill" toe it uses is still assumed in the design of heavier cable bindings, and 75 mm boots are still widely available, especially for telemark technique and more rugged touring. A similar system with a 50 mm "duckbill" once existed for lighter setups, but is obsolete and no longer available. Characteristically, the 75 mm wide binding is chiral, having left and right foot orientations, which the 50 mm and other bindings don't distinguish. The 50 mm was the binding of choice for racing, prior to the adoption of skate ski racing, in the early 1970s. The 50 mm was also designated according to the thickness of the "duckbill" having either 7 mm or 11–13 mm thick soles hence these bindings often had two notches in the bail to clamp boots with different sole thicknesses. Another 50 mm characteristic, distinct from the 75 mm, and still seen in present day 75 mm boots, was the absence of a cable groove in the heel.
Telemark
Like Nordic bindings, Telemark bindings fix only the toe leaving the heel free to move. The main difference is that Telemark bindings are more heavy-duty to withstand the increased forces encountered in high speed descents. The cable binding (aka Kandahar binding), where the toe section of the boot is anchored, and an adjustable cable around the heel (for which there is a groove in the heel of the shoe) secures the boot. Used for cross-country (to a certain extent), TelemarkTelemark skiing
Telemark skiing is a form of skiing using the Telemark turn. Unlike alpine skiing equipment, the skis used for telemarking either have a binding that only connects the boot to the ski at the toes, just as in cross-country skiing, or may be released to only connect there.Telemark turns are led with...
and ski jumping
Ski jumping
Ski jumping is a sport in which skiers go down a take-off ramp, jump and attempt to land as far as possible down the hill below. In addition to the length of the jump, judges give points for style. The skis used for ski jumping are wide and long...
.
While binding designs vary, before 2007 almost all dedicated Telemark models had been designed to fit boots with 75mm Nordic Norm "duckbill" toes. However, in late 2007 Rottefella introduced the New Telemark Norm (NTN) binding which uses a different boot sole, co-developed with the Crispi and Scarpa boot companies.
Alpine ski touring
Also known as Randonee, an Alpine Touring skiSki touring
Ski touring is a form of backcountry skiing involving traveling over the winter landscape on skis under human power rather than through the assistance of ski lifts or snow vehicles. It can take place in terrain ranging from perfectly flat to extremely steep...
is a special ski binding that allows the heel to be clipped down to the ski when skiing downhill, but which allows it to be released when climbing.
Skiboard and Snowblade Non-release binding
Traditionally, skiboards and Salomon's Snowblade have used non-release plate bindings. The reason being that skiboards and snowblades have traditionally been 100 cm in length or less, so the torque during a fall was assumed to be small enough that a releasable binding was not necessary. However, in recent years, as skiboarding has become a more established niche sport, releasable bindings have become a viable option to decrease the chances of injury. Spruce Ski created a riser which adapts between the standard 4 cm by 4 cm four-hole skiboard binding and standard ski bindings; furthermore, Spruce began selling their 120 cm skiboard in the 2005-06 season which are only available with their releasable setup. Additionally, Salomon now offers most of their Snowblades with releasable ski bindings as well. Many riders still prefer the plate-style bindings, and SnowJam and Bomber both make high quality plate bindings.History
- See also: History of skiingHistory of skiingSkiing, or traveling over snow on wooden runners, has a recorded history of almost five millennia.- Ancient history :The first hints to the existence of skis are on 4500 to 5000 year old rock drawings, e.g. at Rødøy in Norway or at Steinkjer , which depict a man on skis holding a stick...
Telemark skiing
Telemark skiing is a form of skiing using the Telemark turn. Unlike alpine skiing equipment, the skis used for telemarking either have a binding that only connects the boot to the ski at the toes, just as in cross-country skiing, or may be released to only connect there.Telemark turns are led with...
and cross-country
Cross-country skiing
Cross-country skiing is a winter sport in which participants propel themselves across snow-covered terrain using skis and poles...
skis were developed from the Ugro-Lapp type.
Norheim's binding
One of the first recorded advances in binding design was made by Sondre NorheimSondre Norheim
Sondre Norheim, born Sondre Auverson, was a Norwegian skier and pioneer of modern skiing. Sondre Norheim is known as the father of Telemark skiing.-Background:...
, the "father" of modern skiing. His binding included a leather toe strap that was fastened tightly with a buckle, and a heel strap of small birch roots twisted into a rope. The heel strap started at the toe, looped around the heel, and forward again to the toe. The heel strap pulled the boot forward into the toe strap, so the ski would not fall off when pressure was released on the toe. The strap had to be flexible and elastic in order to allow it to keep tension on the heel as the skier strode forward and the heel lifted from the ski.
First introduced in 1850, Norheim's binding allowed a much longer striding motion that greatly increased cross-country speeds, and this quickly became widespread. It also allowed the ski to be directed by twisting the foot, transmitting the torsion to the ski through the toe strap. Techniques based on this ability were developed over the next few years, replacing the former technique of dragging a large pole in the snow on one side or the other to drag the skier in that direction. These new techniques spread throughout Telemark
Telemark
is a county in Norway, bordering Vestfold, Buskerud, Hordaland, Rogaland and Aust-Agder. The county administration is in Skien. Until 1919 the county was known as Bratsberg amt.-Location:...
and would later be named for the region. Norheim made a splash when he introduced this publicly at a 1868 ski jump meet, where the contestants were required to ski up the hill, down to the jump and then jump, and marked on all phases. Norheim's smooth linked turns stunned the crowds, and he won the competition.
Huitfeldt's advances
Fritz R. HuitfeldtFritz R. Huitfeldt
Nicolay Fritz Reichwein Huitfeldt was a Norwegian sports official, writer and producer of skis and ski bindings.He was born in Borgund as a son of stipendiary magistrate Hans Jørgen Hansen Huitfeldt and Fredrikke Ambjørnsen...
drove the evolution of the ski binding over the next 20 years. In 1894 he introduced the use of semi-circular metal hooks at the toe to attach the straps. The hooks were positioned to tightly fit to the sides of the boot, keeping the ski centred and eliminating any "flop" that the formerly loose straps allowed. The heel strap was also attached to the same hooks, but because of their rounded shape, the required range of motion was provided by the straps sliding up and down on the hooks. This allowed the heel strap to be replaced by a less flexible leather strap. Together, these changes dramatically tightened the binding, greatly increasing control.
In 1897, Huitfeldt further improved the design by changing the toe piece. Instead of hooks, he drilled a rectangular hole through the ski from side to side, and passed an iron bar through it. The bar was then bent up on either side, locking it in place, and then formed to fit the toe of the boot. This improvement once again dramatically improved the firmness of the fit. Finally, in 1904 he adopted the Hoyer-Ellefsen toggle, a lever that replaced the buckles. This not only greatly improved mechanical advantage, further improving the strength of the binding, but also made the system much easier to put on and remove. Better yet, the geometry of the attachment points meant the heel strap was mechanically attached below that of the toe strap, which provided a constant "diagonal downpull" that naturally returned the heel to the ski.
Huitfeldt style bindings were by far the most popular system for decades, with the only major change being Marius Eriksen's 1920 introduction of pre-formed plates that were screwed on top of the ski. Other binding systems did exist, in particular a class of bindings originally introduced by Mathias Zdarsky
Mathias Zdarsky
Mathias Zdarsky was an early ski pioneer and is considered one of the founders of modern Alpine skiing technique. He was probably Austria's first ski instructor. He was also a teacher, painter and sculptor....
that replaced the heel strap with a long metal plate under the sole of the boot, hinged at the front to allow the heel to rise. The heel was held to the plate by a short strap attaching at the back. These gave even better control than the Huitfeldt design, but so firmly attached the leg that injury was a real problem.
Cable bindings
- Main article: Cable bindingCable bindingCable bindings, also known as Kandahar bindings or bear-trap bindings, were a class of ski bindings widely used through the first half of the 20th century...
The final major improvement to the Huitfeldt "free heel" designs was the replacement of the heel strap with a metal cable and springs. First introduced around 1932 and named for the Kandahar Ski Club in the UK, cable bindings would be almost universal into the early 1960s.
The Kandahar design offered two advantages over the earlier designs. The use of a spring to provide tension allowed fine control over the mechanics, and a smooth action that did not suddenly increase tension at the end of the stroke. It also allowed the skier to adjust the tension by moving the spring or turning a control knob, allowing for different conditions and skiing style and stride. More important was the addition of two small hooks on either side of the ski near the heel. When skiing downhill, the skier could clip the cable under the hooks, locking down the heel and providing much greater control. Now the ski could be turned by rotating the leg, forcing the ski to stem
Stem Christie
The stem Christie is a technique in skiing for turning. It is a refinement of the basic stem technique, where prior to the turn the uphill ski is stemmed from being parallel with the downhill ski to form a V shape....
. When it was time to climb back up the hill, the cable was unhooked and returned to being a normal cross-country binding.
The introduction of dedicated ski lifts in 1908 led to an evolution of skiing as a sport. In the past, skiers would have to ski or walk up the hills they intended to ski down. With the lift, the skiers could leave their skis on, and would be skiing downhill all the time. The need to unclip the heel for cross-country use was eliminated, at least at resorts with lifts. As lifts became more common, especially with the introduction of the chairlift in 1936, the ski world split into cross-country and downhill, a split that remains to this day.
For pure downhill skiing, the Kandahar was a problem. In particular, the metal toe clip so tightly clamped the front of the boot that even small sideways motions of the tip of the ski could twist the lower leg, and spiral fractures of the calf were common. The death grip led to the nickname "bear trap bindings", and it was estimated that 1% of skiers suffered an injury on any given day.
During the 1930s it was discovered that an improvement could be made by removing the toe strap from a typical Kandahar binding. Instead, the metal cup was bent inward to slightly wrap over the top of the boot, or at least the top of the sole. Although the resulting clip was much less solid than the strap, in the case of a forward fall the boot would rotate up and out of the cup, releasing the leg. Although this was an improvement, it was a small one.
Safety bindings
In 1937 Hjalmar Hvam broke his leg skiing, and while recuperating from surgery, invented the Saf-Ski toe binding. This was a metal clip with a pyramidal top that fit into a slot cut into the sole of the ski boot. When the boot was rotated forward, the slot on the toe eventually rose above the metal pyramid, allowing the toe to release from the ski. The system was considered with suspicion by professional skiers, especially when Olaf Rodegaard released during a race. However, Rodegaard credits the release with saving him from a broken leg. In the post-war era, Hvam sold several thousand pairs of Saf-Ski's, in an era when downhill skiing was in its infancy. Hvam continued to sell the Saf-Ski into the 1960s, but in 1966 his insurance rates increased so dramatically that he was forced from the market.A dramatic advance was introduced as the Look Nevada
Look Nevada
Look's Nevada, released in 1950, was the first recognizably modern ski binding. The Nevada was only the toe portion of the binding, and was normally used with a conventional cable binding for the heel. An updated version was introduced in 1962 with a new step-in heel binding, the Grand Prix...
in 1950. The Nevada held the toe centred over the ski using two metal fingers shaped into an upside-down V. The fingers were pivoted to allow motion to the sides, and centred with a spring. During a fall, sideways torsion could overcome the force of the spring and allow the boot to release directly to the side. This design was quickly copied by other vendors, notably Marker, and had the first real impact on the dominance of the classic fixed-toe bindings. By the late 1950s, there were about 35 different release toe bindings on the US market, most of which used a normal Kandahar-style heel cable.
The first modern heel-and-toe binding was the Cubco binding, first introduced in 1950 but not popular until about 1960. A heel-release binding faced the problem that there was no obvious place to attach to on the heel, so the Cubco solved this by screwing small metal clips into the sole of the boot. This also eliminated the changes in performance as the sole of the boot wore down, or the geometry of the sole changed as the boot wore-in to the skiers foot. Marker introduced the Rotomat, which gripped onto the sole where it extended past the heel, and Look quickly followed suit with their Grand Prix design. By the mid 1960s, release bindings that worked on both the heel and the toe were common, and by the late 1960s the cable binding had disappeared from downhill.
One problem with 1960s release bindings was that the boots were not standardized, and a binding that worked well on one boot might be dangerous on another, or might become dangerous over time as the boot shifted about. This led to the introduction of plate bindings, which used a metal plate firmly clipped to the sole of the boot, and bindings that clamped onto the plate. The plate could be easily removed for walking about. Plate bindings were popular in the US in the 1970s, notably the Burt binding and Spademan binding
Spademan binding
Spademan was a type of ski binding that was fairly popular in the 1970s before toe-and-heel bindings became largely universal. It used a bronze plate screwed into the bottom of the boot as its connection point, held to the ski by a clamp-like mechanism that grasped the side of the plate...
, but never caught on in any major way in Europe. As more and more of the downhill ski market came under control of European companies, the plate bindings disappeared, in spite of their excellent safety records.
The disappearance of the plate and alternate systems was due to a combination of factors, notably the introduction of standardized hard plastic boots. Plastic was first introduced by Lange as a way of improving existing leather designs. As the new material spread through the industry, the sole piece was standardized to allow toe-and-heel bindings to clip on. Plastic had the advantages of being much firmer than leather, not changing shape over time, and having predictable friction characteristics wet or dry. Although plate bindings of the era had much better safety records, notably the Spademan design, the new boots and bindings could be easily adapted to any ski for any skier.
Cross-country
The cable binding remained in use, and even increased in popularity, throughout this period as cross-country skiing developed into a major sport of its own. In this field the speeds were generally not high enough that the release was a serious concern, and the freedom of the free-heel design was perfect for the sport.Change eventually came though the evolution of the Rottafella binding, first introduced in 1927. The original Rottafella eliminated the heel strap, which held the boot forward in the binding, by drilling small holes in the sole of the boot which fit into pins in the toe piece. This would only work if the sole was held very firmly down on the pins, so the binding also introduced a metal clip that was forced down onto the top of the sole of the boot, forcing it onto the pins. When the inventor, Bror With, won a race on the new design, Norwegian Crown Prince Olav ask him what they were, and he responded "Oh, they’re just a couple of rat traps I picked up at the hardware store". "Rottafella" is Norwegian for "rat trap".
Problems with the geometry of the boot sole, which meant only certain boots would work, meant the Rottafella was not widely used. This problem was eventually solved through the same evolution of plastic components that changed the downhill market. In this case the use of highly flexible plastics allowed for a sole that was very strong torsionally and side-to-side, but still had excellent flexibility lengthwise, allowing the heel to rise as with a cable binding. This was standardized as the 3-pin system, which was widespread by the 1970s.
See also
- Skiing and Skiing topicsSkiingSkiing is a recreational activity using skis as equipment for traveling over snow. Skis are used in conjunction with boots that connect to the ski with use of a binding....
- Spademan bindingSpademan bindingSpademan was a type of ski binding that was fairly popular in the 1970s before toe-and-heel bindings became largely universal. It used a bronze plate screwed into the bottom of the boot as its connection point, held to the ski by a clamp-like mechanism that grasped the side of the plate...
- Nava SystemNava SystemThe Nava System was a ski binding offered for sale in the 1980s. The system used a combination of flexible sole plate to keep the boot centered, and a spring-loaded plastic arm that was used to transmit sideways motions of the leg to the ski. This eliminated the need for a hard shell on the boot;...