It’s been over a decade since the late, great big-mountain skier Shane McConkey introduced his Volant Spatula ski, effectively turning alpine equipment design on its head.
Snow, and especially powder, are just waves of frozen water, McConkey reasoned, so why not build skis shaped like the hull of a ship? By dramatically “reversing the camber” in the tip and tail of the Spatula (and later even more dramatically with the K2 Pontoon ski), McConkey found a way to increase floatation and maneuverability for skiers in deep snow.
Today rocker is employed in everything from beginner skis to the foot rockets today’s top downhill racers are driving on the World Cup. According to SnowSports Industries America, the wintersports trade association, reverse camber ski sales were up 22 percent overall (7 percent for flat skis, 45 percent for systems) with over 323,000 units sold last season. Reverse/mixed camber skis represented 58 percent of all ski sales during the 2012/2013 season, and that number will continue to rise as new rocker technology grows in popularity.
But rocker is only one of a plethora of somewhat esoteric but vitally important ski construction technologies. To ensure you don’t walk into the shop unprepared this fall, what follows is OnTheSnow’s Dictonary of Ski Construction Terminology:
Truth be told, rocker has existed since skis were first built with tips. The rise in a ski’s shovel is technically rocker, and it helps the ski do everything from deflect cut-up snow and death cookies to provide a transition point on which to tip the ski into its arc. Rocker, as it’s marketed today, is simply an exaggerated rise in the ski’s tip. Same with the tail of a ski, where increased rocker can make it easier to transition out of a turn, or even to schmear or “slarve” the end of a carve into a kind of sliding skid.
Also commonly called early rise, reverse camber, and even pre-bent, rocker’s exaggerated rise can make it dramatically easier to a roll a ski into the turn without having to aggressively pressure the tip. The more subtle the rocker or early rise, the more effectively a ski will grip the snow once it is put on edge. The more pronounced the rocker, the more likely a ski is designed for hitting the kind of powder you find riding snowcats or hiking out the backcountry access gates, where you can take rocker’s surfy sensations to the hilt.
Camber is the upward flexing arc beneath a ski, and is the very design rocker is “reversing.” By pressuring down on the camber, skiers exert pressure — and control — out to the ski’s tail and tip. Place your hand palm-down in a natural position on a table, then press your knuckles down and watch as your fingertips flex upward to see how it works. Though some skis are built with only reverse camber or no camber, most new skis use some combination of rocker and camber as they seek the perfect blend of float and flex.
Even with all of that flexing and floating going on, a ski’s width and sidecut (see below) still figure into the triumvirate of any design’s most important ingredients. A ski’s waist width — measured directly underfoot — still seems to be the most reliable barometer of what kind of terrain it is designed to hit. Narrower skis are typically built for hardpack and lift-served conditions, where smoother surfaces make it easier to roll from edge to edge. Fatter skis provide stability and a wider platform to even out the inconsistencies of deeper snow, especially in the windblown or wetter stuff.
Sidecut, a.k.a. profile or shape, is a means of measuring the difference in a ski’s width at the tip, waist and tail. Sidecut is frequently described as sidecut radius. Imagine extending the arc of a ski’s sidecut into a full circle. The radius of that circle is called a ski’s “sidecut radius.”
A ski’s waist width — measured directly underfoot — still seems
to be the most reliable barometer of what kind of terrain
it is designed to hit.
The greater difference between the width of a ski’s tip and its waist — the deeper its sidecut — the more quickly a ski can turn, maintaining a shorter arc. On the flipside, the less sidecut a ski has — or the shallower a sidecut is — the more comfortable it will feel in a longer or more relaxed turn radius. Wider tails can also sharpen and accelerate the arc of a turn, while thinner tails can make it easier to finish a turn, even by skidding out of it.
Ski manufacturers can radically alter a ski’s weight and performance by using any number of wood, foam, metal and fiberglass layers between the ski’s base and its topsheet. While foam cores tend to result in a lighter ski and metal laminates tend to result in a stiffer ski, not all materials are easily classified. Heavier woods, for example, can contribute to a damper, more durable core, while lighter woods can have the opposite effect, improving a ski’s spring and flex.
Sidewall vs. Cap Construction
Cap construction, in which the top layer of the ski “caps” the core materials from edge to edge, is often used in less expensive ski production. In many top level skis, the materials are layered like a “sandwich,” with vertical sidewalls covering the sides. Most large ski manufacturers use some sort of cap and sandwich construction mix, providing an ideal combination of the torsional rigidity of a sidewall combined with the weight and cost savings of a cap.
There is a wealth of new ski technology hitting the slopes each winter, and all of it is aimed at improving your experience. Easier turn initiation, more maneuverability and especially more versatility are all part of the endgame in this design race. And while it’s easy to get caught up in all the terminology, we think it’s more fun to focus on all of the benefits. If you’ve still got doubts, get out and try a couple pairs of the latest skis yourself. You’ll be glad you did.