Ski binding

Alpine touring ski boot, binding, and ski crampon

A ski binding is an attachment which anchors a ski boot to the ski. There are different types of bindings for different types of skiing.

Bindings by type of skiing

Alpine

Example of ski binding mounted on a plate

Snow brake in open position

The vast majority of bindings for Alpine skiing 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. The boot is released by the binding if a certain amount of torque 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 setting, because the standards for Alpine ski binding settings are issued by Deutsches Institut für Normung. 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 50 years old or older). The DIN is usually set by a technician when skis are rented or bought. Ski service technicians and binding manufacturers recommend that bindings be adjusted and inspected by properly trained service technicians, because incorrectly adjusted bindings may release prematurely, or may fail to release, creating a potential hazard.

Bindings can be sold alone to be mounted to "flat" skis or can be integrated systems. While integrated systems generally provide a more natural flex, better power transmission, and a larger sweet spot, they also add more distance between the boot and the ski. While this is helpful in achieving higher edge angles, the high lift can strain the knees when skiing powder, and will make landings less stable. For this reason, most powder or freestyle skis are sold flat, while most carving and race skis come with an integrated binding system.

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 Rottefella), 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 Rossignol, Madshus, Rottefella, and Alpina 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, Fischer abandoned SNS and entirely switched to NIS; at the same time, Atomic abandoned NNN and switched to SNS.

SNS binding

Obsolete SNS binding on the shoe

Newer SNS binding on the shoe

• SNS (Salomon Nordic System; marketed by 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, Atomic (both belonging to Amer Sports 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 With. 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), Telemark and ski jumping.

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 ski 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

Modern ski bindings are based on the Fennoscandian model of the 19th century. The bindings of Telemark ski and cross-country skis were developed from the Ugro-Lapp type. See History of skiing.

See also

• Skiing and Skiing topics

External links

• The first release bindings
• DIN Setting Calculator
• Ski Bindings - Components, Release Settings, and Buying Guide