Part Three: The Most Important Things to Look For

January 7, 2009

In part two of our four part series, “Understanding & Choosing A Ski”, we discussed the four major varieties of skis - All mountain, freeride, carving and backcountry. While these definitions can be helpful in narrowing things down, there’s still a lot left to think about. Within each of these categories, there are literally hundreds upon hundreds of models (no two of which are the same.) Making the most of your equipment means making an educated decision on which carver, backcountry, freeride, or all-mountain ski best fits where and how you ski.

Where to Start?

Once you’ve honestly assessed where and how you typically ski and decided which of the above four categories you best fall into, it’s time to start looking at equipment. I often find that the best place to start is to curl up with an issue of your favorite skiing magazine (whatever it may be), and read some reviews. While these reviews may cover a very wide variety of models, pay close attention to the adjectives used to describe the few pairs that you think would best fit your skiing. In this part of the series, we’ll help you to link up these adjectives with the actual feelings when you are on the ski, and understand what about a ski makes it behave in this particular way.

Start with Waist Width to Choose your Variety of Ski

Waist width is a great place to start because it’s usually a function of the type of ski and its intended use, and varies from model to model. At one end of the spectrum are alpine and carving skis, which typically have narrower waists which makes it easier for a skier to apply direct pressure along the edge when stopping. These skis also often have larger sidecuts, making them turn faster (more on this in a minute.) At the other end of the line are backcountry and powder skis, which typically have wide waists to support the weight of the skier right at the middle where the pressure is being applied to the snow. Conincidentally, it’s powder skiers who don’t need to be able to apply a lot of pressure to their edges to turn or stop, so this works out nicely. All mountain and freestyle skis fall somewhere in the mid range of waist widths.

As a rule of thumb, skis with a waist width under 72mm are considered carvers, 72-88mm skis are called mid-fats (think all-mountain), 88-100mm skis are known as fats (all mountain to light backcountry), and 100+ is considered “super-fat” (backcountry & high alpine powder only.)

When Choosing a Model, Consider Sidecut & Longitudinal Stiffness

Sidecut is the amount of arc cut out of the side of a ski that gives it an hourglass shape (or, more technically speaking, it’s the average of the tip and tail’s widths, minus the width of the waist, divided by two.) Sidecut is usually the same for all varieties within a model line, but the longest and shortest lengths of some models occasionally have few millimeters less or more sidecut. It’s one of many characteristics of any ski model, but to me, it’s the one that makes the biggest difference.

The sidecut determines a skis’ turn radius - the natural distance over which it makes a 180-degree turn. Thus, a ski with a greater sidecut will be more adept at making short, quick turns, while a ski with less sidecut and a wider waist will track the same turn over a greater distance. Skis with a lot of sidecut are preferred by both beginners (who find that such a ski makes it very easy for them to turn) and seasoned pros who like to make quick, aggressive turns. Skis with less sidecut turn over a greater distance or track completely straight without being forced into a turn. Many backcountry skis have little or no sidecut because the added surface area is needed underfoot to keep the ski on top of softer snow.

Longitudinal Stiffness
Have you ever seen someone in a shop with a ski in hand bearing down against its middle, bending it to some unnatural seeming curve? He or she is testing the skis’ longitudinal stiffness, or how stiff or soft the ski is and how easily it bends. Longitudinal stiffness (or “flex”) is relative to your weight - a heavier skier will perceive a particular ski to be softer than a lighter skier, because he or she has more weight to bend the ski with. Within a particular model line, shorter skis and women-specific models are often proportionally softer because they are intended for smaller people with less weight.

Softer skis handle better on softer snow and at lower speeds. They are easier to turn and are often considerably lighter than stiffer models in comparable sizes. In terms of models, You’ll find that backcountry and beginners’ skis are amongst the softest flexing (backcountry skis float better with less flex, and beginners find softer skis easier to learn on), while carving skis and racing skis are the stiffest (because stiffer skis are better suited to high speeds and aggressive turns on hard snow.) A good rule of thumb - if you ever hear your skis “chattering” against the snow, it may be a good idea to try a stiffer ski.

Once You’ve Picked a Model, Think Length

Second only to the choice of ski model in importance is the length of ski you choose. Years ago, the correct length of ski was an absolute number dependent upon your weight, height and ability level - now, it isn’t quite that simple. While you’ll want a size that tops out somewhere along the height of your face, what’s right for one 5 foot 10 inch skier may be completely wrong for another person of the same height, so it’s important to try a few different lengths once you’ve narrowed it down to a model. Most models come in 4 or 5 different sizes.

Longer skis are typically preferred by aggressive alpine skiers who need the control and stopping power a longer edge gives them, and by backcountry enthusiasts who need the added surface area to float atop light, untracked snow. Shorter skis, on the other hand, are sometimes preferred by newer skiers who avoid gaining a lot of speed, and sometimes by freestyle skiers & park enthusiasts who need light, short and nimble skis to perform tricks.

Other Important Terms

While these terms are often only thrown around by industry insiders and the most devoted of gear junkies, it’s helpful to know them.

  • Topsheet: The topsheet is the part of the ski that you look down at, where the graphics are printed. Many topsheets are made from fiberglass and plastic composites that protect the core layers and bind the other layers together.
  • Base: The underside of the ski, a wax coated piece of plastic (called P-TEX) designed to slide easily across the snow.
  • Core: The core refers to all of the many internal materials of the ski (most skis are a sandwich of many, many layers.) Wood, foam, metal and fiberglass are some of the most popular core materials. The skis’ core construction determines its stiffness or “longitudinal rigidity”.
  • Edge: Just what it says - the steel edge on the sides of the ski. The very fine part of the edge that actually does the work and makes contact with the snow is called the effective edge.
  • Contact Points: The two points on the skis’ edge that touch the ground when the ski is laid on its side. These are the parts of the edge that do all of the work during a stopping a manuver, and thus the first places along the edge to dull after many uses.
  • Shovel: The tip of the ski, from the place where the ski starts turning up to the very end.
  • Sidewall: Any material used in a thin strip along the edge of the ski to protect the core materials.
  • Waist: The narrowest point along the ski, typically in the very middle.
  • Laminate: Any number of sheets of protective material (typically fiberglass) layered on top of the core on either side.
  • Cap: A method of construction in which the topsheet wraps around to meet the edge, taking the place of sidewall materials.
  • Torsion Box: A type of construction that encases a specialty core material, usuallly giving the ski a high level of torsional rigidity (see below.)
  • Torsional Stiffness: How much a ski resists twisting. Torsional stiffness is related to longitudinal stiffness, and while all skis aim to be more “torsionally stiff”, it’s often the longitudinally soft skis that have less torsional stiffness and stability.

Links to This Series