Skis buying guide: jargon buster

Skis jargon buster
All the technical terms you need to know before buying a pair of skis Credit: Adrian Myers 2018/ADRIAN MYERS

Learn the lingo used in our ski reviews to help you find the right skis for you this season.

Flex

Flex tends to talk about how a ski bends along its length. Top end race skis will be quite stiff while beginner skis are soft flexing. Flex can also refer to  how easy a ski is to twist from side to side, referred to as torsional stiffness. Again, performance skis for hard snow will be torsionally stiff. Intermediate skis need to be much softer torsionally to allow for mistakes when skiing.

Sidecut

Sidecut tells us how wide the tip, waist (aka underfoot) and tail of the ski are, in millimetres. The bigger the difference in numbers between the tip/tail and waist measurements, the more curved the side edge of the ski and the tighter the turn shape they’ll naturally make. Piste skis tend to be narrow underfoot to help with grip and edge-to-edge speed on hard snow. Powder skis need to float up in the soft snow and are wider.

Radius

The radius of a ski gives us an indication of the shape of arc a ski will naturally scribe in the snow when tilted on its edge. It is, in part, governed by the sidecut of the ski. A ski for tight slalom style turns may have a radius of 12m while a ski for fast, big arcs in soft snow may have a radius of 40m. It is important to know that this is just an indication of the shape of turn. A 14m radius ski in one model may actually be better in bigger turns than a 15.5m radius ski in another model.  Flex and other characteristics can really impact how tight the ski wants to turn. It’s also worth noting that you can make big arcs on a ski with a small radius figure and really tight turns on a ski with a large radius figure, but the number gives you an indication of the type of turn the ski is designed for.

Rocker

Most freeride, all-mountain and big mountain skis have rocker. At its most basic, this means that if laid flat the centre of a ski touches the ground and the front and back of the ski is raised up. This helps turning in powder but detracts from grip and stability on piste, so some skis have rocker only at the tip or tip and tail to balance on-/off-piste performance.. It’s also becoming more commonplace to see rocker used in piste skis, either just in the front or at both the front and back of the ski.

Traditional camber

This is the traditional shape of a ski. If laid flat on the floor the only points touching the ground are just under the tip and tail, and the middle of the ski is raised. Camber can enhance grip as well as aiding turn transition and giving a ski more pop. 

Mounting point

Skis have a recommended location for mounting the bindings. Most come mounted slightly back of centre; mounting them further forward makes skis easIer to pivot and feel more playful, but the tips can sink in powder, and skis are less stable in long, fast turns. Freestyle skis are often mounted centrally so you can rotate quickly and easily to ski switch (backwards). 

Core

Sandwiched between protective topsheet and base, the core is the part of skis you can’t normally see. It’s made from materials that include varying densities of wood including species such as lightweight bamboo and paulownia, and heavier ash and beech, synthetics such as lightweight polyurethane foam and strengthening fibreglass, and reinforcing sheets of metals such as titanium or Titanal (a light, strong aluminium alloy). More unusual materials might include rubbery inserts, electric fibres, honeycomb structures, varying forms of carbon or fibres derived from plants and rocks. In general, lighter materials help make skis lively and flexible. Denser ones make them heavier but stable, and dampen vibrations for a smoother ride.

Sidewalls

If there are walls at the sides of skis, between the metal edges and the protective topsheet, it’s called sidewall construction. Sidewalls add strength to skis and help grip and stability, while also protecting the core.

Cap/partial cap/hybrid cap

In cap construction the skis’ protective topsheet stretches all the way to their edges and there are no sidewalls. Cap skis tend to be more forgiving than those with sidewalls, and easier to turn. Some skis have a partial cap construction, where the topsheet curves part way towards the edges, and then there’s a small sidewall below to add grip. Hybrid cap skis may have sidewalls under the bindings for grip, and cap construction at tip and tails.

Dampening

If a ski judders and vibrates this can really impact its performance. Manufacturers use different materials and shapes to provide a level of dampening to counter these vibrations, whether the ski is designed for piste, all mountain or off piste skiing. It’s a fine balancing act though as you don’t want a ski to be so good at dampening that it negatively impacts other performance characteristics of a ski.