How Snow Skis Work

For years, wood reigned as the classic ski material, but it's since been supplanted by more high-tech designs. Today, your skis are likely to be made from fiberglass or aluminum. But a ski isn't simply a shaped piece of one of those materials; it has many components, which vary in style or size depending on the model. Many of these components have logical names, but we'll go over them here.

The main part of the ski is the base, which comes into contact with the snow. The top of the ski, where the boots attach, is known as the deck, like a skateboard.

Skis aren't perfectly flat. When you place your ski on the floor of a ski lodge, you might notice a slight gap between the center of the ski and the floor. This gap is known as the camber. Think of it as the arch in your foot.

Of course, when you put the skis on and are careening around the slopes and placing your weight on the deck, all parts of the ski do eventually come into contact with snow. But say you're still looking at your ski, unworn, on the floor of the ski lodge. You'll see that parts of the bottom of the ski are touching the floor -- essentially, large parts of the front and back of the skis, with the camber in the middle -- and these areas are called contact points.

Like elf shoes, the front of skis curve up, preventing them from getting caught in the snow. This curved front is called, quite simply, the tip or the nose. The rear end of the ski is called the tail. The length from tip to tail, measured in centimeters, is the overall length.

If you've spent any time skiing, you've probably heard people talk about the edges of their skis. The edges are metal and help you to carve out turns. An effective edge denotes the part of the edge that actually touches the snow when you turn. Shorter effective edges make for quicker, but potentially less steady, turns.

A ski varies in width, and the widest part of the ski is called the shovel, near the front of the ski. The waist width is the narrowest point.

Finally, a ski's sidecut refers to how the ski is shaped from nose to middle. Imagine a ski as a perfectly rectangular board. The sidecut refers to the amount of material cut out of the sides of that board, creating the familiar, gently curved ski shape. A more dramatic sidecut produces a rounder ski that helps a skier to make sharper turns.

In the broad category of alpine/downhill skis, you'll find several different types of skis. Twin-tip skis curve at the tip and the tail. This design helps freestyle skiers to land difficult jumps and even to ski backward. However, twin tips have expanded beyond the freestyle skier market and can now be found, in various forms, as modified alpine, or downhill, skis. Snowboarders who switch to skiing also tend to pick them.

Among twin-tip skis, two options exist: park-and-pipe skis and all-mountain skis. The former are designed for use in a terrain park and the requisite jumping, tricks, harsh turns and rough landings. All-mountain twin tips, as their name implies, are wider in the waist and so better suited to a variety of conditions across the mountain.

All-mountain skis serve as the jack-of-all-trade skis; you also may know them as all-purpose, mid-fat skis or even the one-ski quiver -- ideally, the one set of skis you'll ever need. All-mountain skis are suitable for most skiers and most mountain conditions, and that's why they're the most popular type of snow skis. Again, you have choices: narrow-waisted or wide-waisted. Narrow-waisted all-mountain skis, or carving skis, are usually around 68 millimeters to 75 millimeters. Mid-fat skis run 76 to 88 millimeters, making them usable in powder conditions or on groomed slopes.

Racing skis are reserved for the professionals, and they look like it, too. They're long and strong to handle high speeds. These Barbie doll-like skis are impossibly narrow in the waist (68 millimeters at most). They're also not nearly as flexible as other types of skis because they have to be able to hold up in icy or hard-packed snow conditions. Racers don't want their skis to bend or twist when they are moving at high speeds or attempting a sharp turn.

Powder skis, also called big-mountain or backcountry skis, have a wide waist width, making them ideal for places with heavy powder. That extra surface area helps skiers to float above premium powder. However, they can be difficult to use on slopes with less snow or groomed trails, especially for beginning to moderate skiers. More experienced skiers -- and those with some extra cash -- sometimes buy powder skis as an alternate pair, to be used when conditions warrant it [source: Skis.com]. True backcountry skis have a waist width of 90 to 110 millimeters, while powder skis are easily the widest type of ski, measuring from 110 to 130 millimeters.

Now that we've looked at some of the many types of skis, let's figure out how to size a pair of skis.

Ski sizing or length depends on several factors, including age, height, weight and skill level. As a general rule, people often look for skis that reach the chin but stop below the eyes. With so many types of skis now out there, it's difficult to stick to one guiding rule, but this one can be a good place to start. For adults, whether beginners or advanced, skis taller than the skier's height sometimes are recommended. It's also said that heavier people should have longer skis to better distribute their weight, as should experienced skiers who thrive at high speeds or in rough conditions.

The ski's height and width should be printed somewhere near the ski's tail. Most skis also include a printed number that represents its turning radius, with smaller numbers (say, around 15 meters) indicating that the skis are made for sharper, faster turns.

There are other important factors in choosing a ski, including flexibility. More flexible skis are ideal for beginning to moderate skiers who don't go very fast and need their skis to be flexible to allow them to make turns easily. Less flexible skis are tougher, making them ideal for difficult conditions, fast speeds and sharp, bone-rattling turns. Finally, you want to consider terrain -- where will you be skiing? In one type of environment or many? How often will you be skiing? People who hit the slopes a lot may want skis that require a higher skill level, as they'll "grow" into them.

With all of those factors in mind, as well as the idea that you should probably talk with a retailer about your options, let's take an example of a 180-pound (82-kilogram) male skier. According to Play It Again Sports, an intermediate skier of that weight should look for 170- to 180-centimeter skis [source: Play It Again Sports]. If he's an advanced all-mountain skier, 180-centimeter to 190-centimeter skis are best. On the other hand, that same advanced skier might wish to go with shorter skis, which make it easier to perform sharp turns while sacrificing some stability. In that case, 160-centimeter or 170-centimeter carving skis might be best.

A ski sizing calculator can help you to make a more informed decision. Using the Frostyrider calculator, we input information for a 6-foot (1.8 meter), 180-pound male skier, who wants to ski all-mountain terrain not too aggressively and at an intermediate level. For this skier, Frostyrider's calculator recommends 168-centimeter skis -- only a few centimeters shorter than those recommended by our other chart [source: Frostyrider].

Don't head for the gondola yet. You still need boots and bindings.

Men and women often buy different types of skis because women have a lower center of gravity. Men tend to lean forward more than women, meaning that men's bindings are placed farther forward on the skis. Women's skis also tend to be lighter to offer them the same flexibility that men get out of their heavier skis.

Most all-mountain skis feature what are known as integrated bindings -- bindings built into the skis. Such bindings are common for everyone but advanced level skiers, who often have specific binding needs, especially if they engage in competition. The virtue of integrated bindings is that they are flexible and slightly mobile, which in turn ensures flexibility throughout the ski, even when your boot is in place.

Ski boots should provide comfort, warmth, support, waterproofing, flexibility and a firm link with your ski bindings. A typical ski boot will have a hard plastic outer shell, an inner boot, several clips, adjustments for flexibility and a power strap that allows you to tighten the top of the boot. A forward-lean adjustment permits the wearer to adjust how much he or she may lean forward in the boot. Some boots offer other adjustments, such as a ski-walk adjustment, which lets the top part of the boot flex backward, making walking easier.

There are two main types of ski boots -- rear-entry and top-entry, with mid-entry serving as a kind of hybrid model. Rear-entry boots have fewer clasps -- just one or two in total -- than top-entry boots; rear-entry boots can then be opened wide, allowing you to insert your foot at a shallower angle, rather than from the top. Except for the most expensive models, top-entry boots usually are considered higher-end because they offer superior foot support.

When it comes to buying ski boots, you may prefer to try a ski shop, where you can work with an experienced retailer to find the proper fit. It's recommended that you wear wool socks or other thick skiing socks, as you will when skiing. A decent pair of ski boots retails for around $100, while high-end boots can set you back $400 to $600. Still, major sales are common, so after you figure out what you want, hunt around -- including online -- for a bargain.

For more information about snow skis, winter sports and other related topics, take a look at the links on the next page.