Alpine Skiing Equipment

Jean Baptiste Grange of France
Very few other sports require such an extensive, and often expensive, equipment kit as Alpine Skiing.
Besides the essential gear to slide down the slopes, there are the ski wear components, designed to protect the skier from extreme weather conditions, as well as the protective elements necessary in what has become a high speed sport: a top-level downhill skier can reach speeds of up to 125 km/h on certain slopes, but even the average week-end skier can easily get up to 50 km/h, a speed at which hitting another body, or a tree, can have severe consequences.
The original alpine "downhill" skis were little more than glorified planks of wood. Eventually metal edges were added to better grip the snow and for durability. Downhill ski construction has evolved into a sophisticated technologY. The use of composite materials, such as carbon-Kevlar, made skis stronger, lighter, and more durable. In the late 1980s and early 1990s, manufacturers began producing parabolic "shaped" skis (when viewed from above or below, the center or "waist" is significantly narrower than the tip and tail). Virtually all modern skis are made with some degree of side cut. The more dramatic the difference between the width of the tip, waist and tail, coupled with the length stiffness and camber of the ski, the shorter the "natural" turning radius. Skis used in downhill race events are long with a subtle side cut as they are built for speed and wide turns. Slalom skis—as well as many recreational skis—are shorter with a greater side cut to facilitate tighter, easier turns.
The market offers a staggering variety of brands and models, which can be basically divided into 3 categories according to the skier’s ability; beginners, all-round, advanced. Within the latter two categories, there are different types of ski according to the prevalent use preferred  by the skier.
All- round skis: they can be suited to traditional snow/slope conditions, or designed for powder and fresh snow (sometimes called free-ride skis). In the latter case, the shape, length and weight of the ski will differ from the former: tips and tails will be wider and the waist thinner, length will be shorter and overall the ski will be lighter.
Advanced skis: they are typically racing skis, and differ in terms of the racing speciality they are designed for. Downhill and SuperG skis are longer (between cm 190 and 210), heavier and less tapered at the waist; slalom skis are much shorter (cm 165 -175) and have a narrow waist that considerably shortens the turning radius; giant slalom skis lie somewhat in-between with the emphasis on stabillity and control at high speeds but also a relatively tight turning radius.
The vast majority of bindings 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 on skis or can be integrated to the ski itself. 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.
Poles in Alpine Skiing are used essentially for balancing purposes, to accompany and coordinate the upper body movements of the skier. They must be light, relatively rigid and provide a solid grip. They feature a rounded or star-shaped disc about 5cm from the bottom tip, to be able to float in the snow when planted.
There is no differentiation in poles for ability or snow-type, though giant slalom, SuperG and downhill athlets use special poles which are bent to follow the body’s contours when the skier crouches in the maximum speed position.
Just as with skis, there is a huge variety of Alpine Skiing boots according to the skier’s ability, size, preferred type of snow conditions etc.
They are generally composed of a hard plastic shell with a softer foam liner to provide warmth and comfort. Concerning liners, a thick soft liner will be more comfortable and provide more insulation while thinner, harder liners provide more precision. Comfort has been improved in recent years by the use of conformable linings (usually heated to fit) which allow an otherwise stiff liner to be molded to the foot and comfortably accept a large variety of foot shapes. Shells come in various degrees of stiffness; beginners typically like a softer and more padded boot, while more advanced skiers generally prefer a stiffer boot with a thinner liner.
Softer boots are able to be flexed with less pressure applied to the cuff making them a good choice for lighter or less aggressive skiers and translates into a more forgiving ride. This quality is also desirable when efficiency and comfort during touring is a concern. Softer boots are often lighter as well due to thinner shell material.
Increased boot stiffness generally translates into more precise energy transmission from the skier to the ski. It also provides better support for increased g-loading during high-speed turns, and heavier skiers. Stiff boots however are often less comfortable and heavier than their softer counterparts. Boots which are too soft for a skier will not feel sufficiently responsive, and will over flex during high-performance skiing. Boots that are too stiff for a skier will transmit unintended control movements to the skis, and will not flex sufficiently in varying terrain or during normal intensity skiing.