Shaped vs. Straight Skis
The term "shaped skis" refers to the design or "shape" of the skis. Taking the lead from snowboards, shaped skis are typically broader in the tip and tail and narrower underfoot, making them easier to turn when rolled onto their edges. Older "straight skis" were designed with very little variation in the ski's dimensions and were designed to be "skidded" through turns using a flat ski.
Sidecut and Length
When shopping for shaped skis, it's important to look at four dimensions: the width of the tip, tail, area under foot (called the "waist") and the turning radius. All four will help you to determine how the ski will track through different types of snow conditions and how easily it will turn. A broader tip will help the ski to float in powder snow and blast through crud. A broader tail aids in stability. A ski that is wider under foot will help it to glide through off-piste conditions, while narrower dimensions will help the ski to turn. The turning radius (expressed in meters) indicates how sharply the ski will turn when it's tipped onto its edges. Skis with small turning radii (6 to 10 meters) are very "turny." Skis with large turning radii (18 to 22 meters) are better for wider, high speed turns.
Ski lengths have dropped dramatically over the years. Skiers who once used skis that were 215 cm long are now skiing on boards that measure 172 cm or less. The reason is "surface area." Even though today's skis are shorter, they're wider and offer the same amount of gliding surface area that touches the snow as their older counterparts.
Types of Shaped Skis
In addition to different lengths and sidecuts, shaped skis come in a variety of models that include freeride, freestyle, all-mountain and telemark skis. Choose a freeride ski if you like to ski all types of ski conditions, in-bounds and out. Choose a freestyle ski if you enjoy spending time in the air, spinning 180s and careening up the sides of halfpipes. Choose an all-mountain ski if you spend most of your time skiing in-bounds but enjoy groomed runs, moguls and cutting new paths through the trees. Telemark skis are ideal for skiing into the backcountry for winter camping trips. Characterized by their "free heel," telemark skis can be used for in-bounds skiing as well as in the wilderness.
