The advancement in ski technology over the last decade has resulted in a bewildering array of ski types available. Unless you have some knowledge of what all the differing ski shapes and technologies have to offer, you could end up with a ski that is totally inappropriate for your skiing ability and weight. When equipped with the appropriate ski your skiing skills will progress at a much faster pace and as a result be far more enjoyable. This guide will hopefully aid your understanding of all the technical aspects of a ski and assist in your decision on buying the perfect set of skis for you.
It is important to be honest with yourself when evaluating your skiing ability, having a set of skis that are designed for a level you have not yet reached will impede your progression as a skier and more importantly, stop you having as much fun. We have broken down skiing ability in to three levels.
- Beginner: Persons who are new to skiing or have been skiing a few times that mainly utilise snow ploughs turns and can occasionally complete parallel turns. A beginner skier would feel comfortable on green and blue runs and ski at a slower speeds.
- Intermediate: Skiers that would be able to complete parallel turns in both directions and feel comfortable on all runs up to red and tackle the occasional black run. The intermediate skier may even venture a little off the groomed slopes and go slightly off-piste. Ski at a moderate to high speeds.
- Expert: Skiers that would be comfortable tackling all colour runs and would be happy to go into the back country for their off-piste skiing. An expert skier would have full control and confidence in their skiing abilities in all conditions and would have knowledge of Avalanche safety and even some mountaineering experience. Expert skiers would be comfortable skiing at a very high speeds.
Ski Rocker & Camber
Rocker, or negative camber, is the amount of curve a ski has from end to end with the centre of the ski touching the snow and the tip and tail bending away from it. This curve keeps the ski above the snow when in motion, preventing the front of the ski digging in to the snow and stopping the forward glide. Much like the hull of a boat, the rocker shape creates a lot of lift, lending itself perfectly to skiing off-piste in powder where this float keeps the skier above the snow. The rocker shape is also used for freestyle skiing as the shape is great for performing spins and riding rails (jibbing).
Camber is the amount of curve in the middle of the ski that bends away from the snow similar to the shape of a bridge. This creates pressure at the tip and tail of the ski and when the skiers weight is pressed into the camber when performing a turn, effectively flattens it out adding more edge contact and increased grip. When the skier comes out of the turn the camber regains its shape like a spring and sets itself for the next turn. This spring like affect aids the skier to generate more powerful turns and gives 'pop' when jumping off ramps (kickers).
A ski with no real camber or rocker would be considered 'Flat'. In a 'Flat' ski the edges are in constant contact with the snow, with the skiers weight being distributed evenly along the ski. On harder snow, this distribution of weight along more edge offers less grip than a cambered ski but as a result are easier to turn. Flat skis lend themselves to freestyle skiing, powder and park skiing where skiers undertake riding rails and jumps.
As a ski with rocker or camber can be limiting in its' design most manufacturers blend the two ski shapes to combine the benefits of each into one ski. These two designs can be combined with more of either rocker or camber to increase either the float or 'pop' of the ski.
The length of the ski depends on weight of the skier, ability level and preference. A lighter skier will need less surface area to keep them above the snow where a heavier skier will need more surface area to distribute the additional weight. As a rough guide a skier who weighs 50kg / 8 st would require a ski approximately 145cm in length. A skier weighing 80kg / 12 st would require a ski of around 165cm.
Contradictorily to some board sports, as your skill level improves, the length of skis used would increase slightly as higher speeds can be achieved with longer skis. Ultimately, the length of skis you ride is down to what feels right underfoot.
The traditional downhill ski shape features a relatively thin waist (middle) where the ski binding will be mounted and widens towards the front of the ski and to a lesser extent towards the rear. This widening provides more surface area to be in contact with the snow and creates an inner curve (radius) that allows the ski to make tighter turns.
Powder and off-piste skis tend to be much wider throughout and do not feature such an exaggerated radius through the middle section. The wideness gives float in powder and the less aggressive radius allows a more cruisy style and longer drawn out turns that powder skiing is all about.
An all-mountain ski is the most versatile of ski shapes and offers good performance on and off-piste. As the name suggests, an all mountain ski is a blend of both downhill/piste and powder ski shapes. These skis feature enough width to give float in powder while having a thinner waist so there is plenty of grip when on-piste.
Tip and Tail Rocker
All skis have some degree of rocker at the tip of the ski. However each ski will have different amounts of tip rocker, just like ski rocker in general, the amount of tip rocker (both in height and length) will generate more lift and have an affect on how much ski will be in contact with the snow. Rocker in the tail is to enable the ski to travel backwards, which is known as 'switch' since the direction you would normally be facing is reversed. When the camber on some skis is compressed, the amount of tip and tail rocker actually increases by a considerable amount giving more float in powder and allows tighter turns. A little rocker in the tail will also help the learner skier as it will release from a turn earlier and easier than a flat tail. A ski with no real rocker in the tail will suit the faster on-piste skier, as the edge of the ski will hold firm when turning.
Flat Tailed & Twin Tip Skis
Flat tailed skis are designed to go in one direction and one direction only. A twin tip ski will have a raised tail rocker so that it can be ridden backwards as well as forwards. A directional twin ski would still have a raised tail rocker to a certain extent but would not perform as well as a twin tip at travelling in a backwards direction.
Extruded & Sintered Ski Bases
The underneath of the ski is known as the base and is made from polyethylene, a type of plastic, in the form of pellets. The difference between the two types of base is solely in the manufacturing processes used.
To make an extruded base the pellets are melted together, opposed to a sintered base where the pellets are crushed together under high pressure to form a ski base. The extruded base is cheaper to make and is found mainly in cheaper skis. This base is very durable and holds up well to the knocks and scrapes that comes when learning to ski.
A sintered base, being crushed to gain its' form, has small holes and is slightly porous because the pellets have not been fused together. These holes allow a far greater wax absorption, and as a result the ski is a lot faster than a ski with a extruded base.
The term 'Flex' refers to how much a ski bends when under pressure and are categorised into longitudinal (flex along the length of the ski) and torsional flex (twist flex). A flexible ski would suit an entry level skier well as the flexibility is more forgiving than a stiffer ski. Less rigid skis will skid across the surface of the snow to a greater extent when turning. A stiffer ski with little flex would skid far less, holding its' edge when turning suiting advanced skiers that can travel at speed and require a responsive ski.
Laminates, sidewalls and core materials coming soon.