Skis

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Overview

The long thin things on your feet that make sliding possible. There are 4 main categories of skis that are used for different types of skiing - Alpine, Cross-country, Telemark and Terrain Park. Each type is outlined below.

Downhill (Alpine)

Introduction

Skis come in a bewildering variety of length, width, separate widths of tip, waist and tail, longitudinal stiffness, torsional (twisting) stiffness and, of course, colour. There are a variety of gizmos added to skis including flashing lights, vibration dampeners, torsion bars, magic shapes and whatever else the marketing department comes up with. The only good news is that colour does not affect performance (apart from the universal truth that red things go faster), nor, I suspect, do many of the gizmos.

Choosing skis

As a general proposition soft (more flexible) and shorter skis deliver easier turns and faster progression for beginners. As your ability increases stiffer and longer skis deliver better performance and control. Softer skis tend not to hold an edge at speed resulting in lack of precision in turns. They may also feel "squirrelly" which means they are not as directionally stable underfoot at faster speeds. There are exceptions to this rule, such as park skis and specialised powder skis.

Again as a general proposition, the wider a ski is the more effective it is in ungroomed, slushy or cruddy snow. This is because a wider ski gives more flotation.

A good rule of thumb for ski length is that the tips should be somewhere around your nose when the skis are stood vertically on their tails. Beginners will find a shorter ski easier to handle.

Ski manufacturers' marketing blurb usually has a slew of pseudo-scientific mumbo jumbo with lots of numbers and indices and graphs and stuff. This stuff may measure real things, like flex patterns and use real SI units like Newtons but it is unreliable. Unlike with bindings, there is no international standard for ski analysis and even if the statistics measure real stuff the measurement technique will be different. One simple way to discover this is to do a direct comparison with skis from different manufacturers that are nominally the same length. There will be a significant difference. If they can't agree on how to measure a ski's length what chance is there for stuff you can't actually see? The numbers are possibly useful for comparison within a manufacturer's range, but useless for comparing skis from different manufacturers.

The ideal way to buy skis is to demo them before you buy. Many ski shops located in resorts have a stock of skis of various brands that they will let you try before you buy. This allows a direct comparison. You will generally pay a hiring fee, but if you end up buying this fee is almost always deducted from your purchase price.

When you are demoing do not go overboard with the number of skis you try. Talk to the ski shop about what you want and listen to their recommendations. It is hard to remember the characteristics of more than 3 or 4 skis each day. Try to ski each ski on the same runs so your comparison is as accurate as possible, although you should remember that snow conditions will change over the day and that as you get more tired your technique may deteriorate which will affect your perception of the ski. Once you have narrowed your choice to a couple try those two again, unless one ski is an absolute standout.

Types of Alpine skis

You may hear references to "shaped" (or carve, or parabolic) and "straight" skis. This refers back to a revolution in ski design that happened in the mid 1990s. The change was an increase in sidecut (the difference between the tip and tail measurements, and the waist measurement or the curve to the edges in plan view). At the same time skis became shorter. The additional sidecut made skis easier to turn, and made carving easier. Straight skis are the old style skis. Compared to the newer ones they look straight although they all have some sidecut. There was resistance to the change from old farts, but that argument was lost long ago. No manufacturer makes straight skis any more, except for racing.

Powder skis are fat. Big wide, soft, flexible boards. They tend to have not much side cut, but rely on the flex of the ski, and angulation, to turn within the snow. Turns on powder skis tend to be wider radius. Generally only worth getting if you ski NZ club fields or powder-rich northern hemisphere ski areas. Get caught in a lift line with these and you will look like a plonker.

There are many manufacturers, each of whom have a large and ever changing range. This article provides Links to Ski Manufacturers Web Sites, which should give current models and the conditions foe which they are intended. Although there are many brands there are only a small number of manufacturers as there has been significant consolidation in the industry over the last couple of decades. This is true for most of the ski industry.

Ski length chart, which should be used as a tool, not as an absolute guide. Ski characteristics vary and your retailer should be aware of any variations appropriate for a particular brand and model.

Cross Country

Introduction

There are a number of types of cross-country skis.

For track skiing, the main types are Classic skis and Skating (skate) skis.

  • Classic tracks are usually machine groomed in parallel pairs 60mm to 70mm wide and similar depth around a circuit or trail. Classic tracks suit narrow skis and boots. Wider skis or boots catch the sides slowing them down.
  • Skating tracks are usually a flattened path about 2 to 3 metres wide, often machine groomed with classic tracks on one or both sides.

For off track skiing and backcountry touring the skis used tend to be wider, shorter and heavier, often with steel edges for greater control and security on hard snow. Ski types used for touring include Light Touring skis, Backcountry (rugged touring) skis, Telemark skis and Alpine Touring (AT) skis.

Skis used for the classic kick-and-glide technique in tracks and for touring may or may not have a waxless (patterned) base. The pattern aids uphill skiing by reducing backward slide. In the absence of a pattern, classic skis use grip wax or klister to achieve the same effect.

Types of Cross Country Skis

Classic track skis are designed primarily for the fast, efficient kick-and-glide technique on smooth snow, preferably the groomed tracks and trails found at resorts and skiing centers. Track skis are long, narrow (~40mm) and light making them very fast in groomed tracks. The length of a classic ski should be more than the height of a skiier, but less than the height to the raised wrist. They have a stiff double camber which may have waxless bases (see below) for gri, or is waxed for grip.

Skate skis are designed for skating, the fastest Cross-Country skiing technique similar to ice skating and inline skating, on groomed Cross-Country skate trails or icy morning crust. Skate skis look similar to classic track skis [long, narrow (~40mm) and light] but are normally about 10cm shorter than a classic ski for the same person. and typically have snubbed tips. They have stiff single cambers and lots of resistance to twisting, pushing forces. Skate skis have waxable bases waxed full length for glide as skating does not need grip from wax or waxless bases.

Light touring skis are ideal for anyone interested in heading out through a city park, golf course or the fields behind their house - places without machine-groomed snow. Light touring skis are wider (~50mm) underfoot than track skis for more stability on descents and over uneven terrain. They may have wider ski tips to keep the ski floating on top of soft snow rather than plunging beneath it. Light touring skis may be slightly shorter than track skis for easier turns. They perform well on groomed trails and the narrower models can also make dedicated track skis for skiers who are willing to sacrifice some speed and glide. They may have waxable or waxless bases.

Backcountry skis (also called rugged touring skis) are designed for breaking your own trail, often in deep snow, in rugged backcountry terrain where conditions are ungroomed and unpredictable. Skis in the backcountry category are wider (typically 65/55/60 to 80/65/70 mm) and heavier than light touring skis for more stability and flotation in softer and deeper snow. Longer models provide more glide for point-to-point touring. Shorter models with greater sidecut are easier to turn. Backcountry skis almost always have metal edges to bite into hard snow and ice. They may have waxable or waxless bases and be fitted with skins for climbing.

Telemark Skis - See below.

Alpine Touring (AT) Skis - See below.

Choosing Cross Country Skis

Waxable vs. Waxless Bases - Cross Country skis need to grip the snow when you climb hills or stride on flat terrain (“kick and glide”). Skis achieve grip in 1 of 3 ways:

  • the bottom of the ski has a pattern or material that grips without grip wax (waxless), or
  • grip wax is applied to the base (waxable), or
  • climbing skins are attached to the bottom of the skis.

Waxless skis (step, fischscale, nowax, kinetic, zero, microschuppe, multigrade, chemical, mica, mohair) are a popular choice because they are convenient and provide grip in a variety of snow conditions. Their textured pattern or material digs into and grips the snow, though it reduces glide somewhat. Waxless bases are often available on classic track skis, light touring skis and backcountry skis.

Waxable skis require a bit more work, but they can outperform waxless models if their grip wax is precisely matched to snow conditions. The grip wax must be soft enough for snow crystals to dig in and grip, but not so soft that snow sticks to the skis. In consistent temperatures above or below freezing, well-waxed skis perform superbly. When temperatures are erratic or right at the freezing point, grip waxing is difficult and waxless skis are the better choice.

Climbing Skins (also known as skins) may be used for climbing up steep slopes. These synthetic, carpet-like strips running along the length of the skis are attached to the base of the ski with grip, buckles and straps or some combination of these. Skins give skis the traction necessary for skiing/climbing uphill. When it is time to start skiing downhill, the skins are removed. Skins running along the full length of the skis maximise climbing ability but drag when touring on the level. Kicker skins, running along only the middle third of the skis, sacrifice some climbing capability for some glide when touring on the level if the skis have sufficient camber. Skins are often used on Alpine Touring and Telemark skis and sometimes used on backcountry skis.

Ski Length - Your correct ski length will usually be based on your weight Each ski model comes in a selection of lengths, measured in centimetres. Manufacturers may provide sizing charts giving appropriate ski lengths. In most cases, body weight and camber of the skis are the main determining factors for ski length, see under "Camber" below. For some track and touring ski models you may still be able to select about the right length by simply raising your arm and measuring to your wrist. Unsure of the correct length for you? Long skis glide best. Shorter wider skis are slower but easier to turn for recreational skiers or those skiing in rugged terrain. Between size ranges? Go shorter if you’re less experienced or go longer if you’re very athletic or if you intend to progress quickly.

Width and Sidecut - Ski width is measured in millimeters at 3 locations: the tip (the widest point near the front of the ski), the waist (the narrowest point near the middle of the ski), and the tail (near the back of the ski). The resulting hourglass shape is called the sidecut. For skis for use in tracks, which are usually groomed with a width of 60 to 70mm, it is important that the tips be no wider than 70mm. The sidecut should also be minimal so the skis glide straight and efficiently, and bindings and boots should not scrape the sides of the tracks. For backcountry ski touring where you're likely to encounter deeper snow, hills, trees and other obstacles look for skis with more width and a moderate sidecut for better flotation and easier turning. If you want one pair of skis for both in and out of track touring, look for a touring ski about 65 to 70mm wide without metal edges. You also may consider a metal-edge touring ski that is relatively narrow (again, up to 70mm width). Telemark and Alpine Touring skis have pronounced sidecuts with broader tips and tails to facilitate carving without getting caught in the snow.

Camber - Track and touring skis have a pronounced arch (camber) that holds the skis above the surface of the snow and rely on the skier's weight to flatten their profile for traction. This camber acts like a spring, assisting forward momentum for the classic kick-and-glide technique. Classic track and backcountry touring skis that use grip wax or waxless bases for grip usually have a double camber. When you place double camber skis base to base and squeeze them together moderately. the end thirds flatten against each other but the middle third (the waist or “grip zone”) remains arched and only flattens when squeezed strongly. Double camber skis are the correct camber for your weight if a piece of paper placed under one ski below the binding can be removed when you stand with your weight evenly distributed on both skis, but it is held firmly when you put your weight on one ski. On snow when skiing with equal weight on both double camber skis, the waist or “grip zone” of the ski remains arched up off the snow to assist glide, but when you place all your weight on one ski, you push the grip zone of that ski into the snow to give traction for your kick forward. Like Downhill skis, Telemark and Alpine Touring skis generally have a soft single camber for easier turning and better control on descents. When you place single camber skis base to base and squeeze them together. the entire length of the skis flatten against each other with moderate squeezing. Skating skis generally have very stiff single camber.

Flex - Track skis resist twisting (flex) for efficient gliding while backcountry skis have more flex for control while turning. Both Telemark and Alpine Touring skis have more flex than other Cross-Country skis to help you navigate deep powder. A ski’s flex influences speed and turning. A soft-flexing ski grips better and turns more easily on soft snow and at slow speeds. A stiff flex works best on firm snow and at high speeds.

Metal Edges - Like Downhill and Alpine Touring skis, Telemark and backcountry skis usually have metal edges that bite into icy or steep snow to make maneuvering on a slope easier and safer. However, they add weight to the skis.

Telemark

Telemark skis can be used for cross-country backcountry touring and for downhill skiing at resorts. Telemark skis are generally shorter, wider (typically 85/65/75 to 110/70/100 mm) and heavier with more sidecut than backcountry touring skis. They can ski steeper downhill slopes but require more effort to tour. Alpine Touring (AT) and Downhill skis are sometimes fitted with Telemark bindings which allow stride and glide when touring, but have heels which cannot be locked down. Telemark skis usually have waxable bases waxed for glide and use skins for climbing

Alpine Touring (AT)

Alpine Touring (AT) skis and bindings allow advanced alpine skiers to tour the ungroomed backcountry to ski steep downhill slopes using their already-honed alpine skiing techniques. AT skis are usually lightweight downhill skis with AT bindings which unlock at the heel and hinge at the toe for stride and glide when touring, and lock down at the heels for descents. AT skis are generally shorter, wider and heavier with more sidecut than backcountry touring skis so require more effort to tour. AT skis usually have waxable bases waxed for glide and use skins for climbing.

Terrain Park