SKIS

If you look in a good ski shop these days, you will see many skis suited to different types of skiing. Here the features of a ski are listed, with a list of different types of ski at the bottom, explaining why they are good for these types of skiing.

Before looking at types of ski it is important to understand the parts and properties of a ski, and what they do. There is a lot more to a ski than you might realise, and things you might not have noticed can make a large difference to how a ski acts. The information here is about modern carving skis, as they are by far the most common kind of ski today.

The Base

The base is the area on the bottom of the ski, that comes into contact with the snow. Generally when looking to buy a ski this will not be something you will consider that much, although it is a very important part of the ski. There are still many different types of bases, but they generally all vary in similar ways. Some bases have graphite in them so that they are more scratch resistant, and there are different qualities of materials, which absorb and hold wax better than others. Also when a base is ground (sanded down by a machine) it will be left with slight grooves running along the length of the ski, depending on how deep and far apart these grooves are, it makes the skis better for different snow conditions. Generally the deeper and further apart the grooves are, the better they will be in wetter snow. Most skiers however use their skis in all conditions, and are fairly unaware of the differences base structures can make.

The thing that makes the largest difference with the base, is keeping it well waxed. There are also many different types of wax you can use, usually suited to different temperatures of snow, although again some have graphite in them etc.

The base of a ski can get scratched if it goes over objects such as stones etc. For general skiing as long a ski is kept well waxed, the amount of scratches on the bottom will not make much difference. Although if you do have large scratches it is best if they are down the length of the ski.

The Edges

The edges are the metal strips that run down the side of the skis. Edges are very important, and can make a big difference to the performance of the skis. There are many things that effect the edges and how they work, like radius, sharpness and stiffness (stiffness is explained more in it's own section). Lets look at the radius firstly.

If you look at your skis you will see that (unless you have really old skis) they are wider at the tips than the middle, and you probably find that they have a radius (or R) written on them somewhere with a measurement written in metres. This is because the edges have been shaped so that they make part of a circle with the radius that is stated. If the ski is tilted so that the edge pushes into the snow, this radius will make the ski turn in a circle with that radius. So therefore if you are going to use the edges properly, you need to match the radius with the style of skiing you intend to do. For slalom skis the radius is often about 12m, for more allround skis the radius is often nearer to 16-20m, and for skis intended for high speeds with big turns the radius will be closer to 30m. The radius stated for a ski is not necessarily the radius a ski will always turn at though, as the radius will change with how much the ski bends. If a ski can bend a lot, several radii will be possible from the ski depending on how hard the ski is pushed, and how much it is leant over.

How sharp the edges on skis are makes a big difference with cutting into the snow. Edges that have just been sharpened will have less resistance and cut into the snow better than edges that haven’t, giving you more edge control. Also the angle that the edges are sharpened to makes a big difference. Most skis will have edge angles between 90 degrees and 88 degrees, racers though will use smaller angles anything down to about 80 degrees. This enables their skis to cut into the ice that they race on. Edge angles like these will not work on all skis though. Apart from the skill needed to use them, a ski needs to be very stiff to handle a very sharp edge, or the ski will just bounce around in the snow with the edge catching and releasing, giving less control than if the edges weren't so sharp.

Stiffness

Generally the stiffer a ski is the better it will be able to hold an edge in hard packed snow, and the better the handling will be at higher speeds. Which all sounds very good, but also the stiffer a ski is the less forgiving it will be if you make any mistakes. So although it can let you carve like you had never imagined, it can also throw you to the ground before you realised you did anything wrong.

To explain quickly why this happens, when a ski is traveling along it will hit lots of small bumps in the snow. If a ski is really flexible these bumps will make the tip and tail of the ski bounce out of the snow, releasing the edges along those areas, and at high speeds can make the whole ski shake. With a stiff ski though, the stiffness will make sure that the edges stay in the snow a lot better giving you more edge control. The problem is if you get into trouble and need to release the edges to recover, they won’t release so easily with stiffer ski and could mean that you end up on your face. This is also a reason why twin tip skis are generally more flexible, as you can use the flex to perform tricks and it will also get you out of trouble on those dodgy landings. Generally beginners use more flexible skis, so that they can get away with making more mistakes, and racers use very stiff skis, as they need all the performance they can get. The average skier will have a ski in the middle of the two extremes, as they want a ski to have fun on, but that is still comfortable and easier to control.

Torsion is also very important for skis as if a ski will twist the edges will not push on the snow with as much force. This effects a ski in very similar ways to stiffness along the ski with torsionally stiffer skis being less forgiving and intended more for racing.

Camber

The amount of camber a ski has is generally measured by the height the middle of the ski sits above a flat surface when there is no weight put on the ski. In general camber gives a ski more pop, which makes a ski more lively and it lets you jump between turns more easily/energetically. You still don’t want too much pop though as then the skis would be too lively.

Skis are shaped like this so they push into the snow along their entire length. This shape means the the ends of the skis will always have a force pushing them into the snow, keeping the entire length of the edges in contact with the snow. Stiffness also plays a large part here, the camber shape is what keeps the length of the skis pushing into the snow, but it is the stiffness that determines how hard the skis push. So although although camber is measured by the height the middle of the ski sits at, the liveliness it creates is also very dependent on stiffness.

Width

The width of a ski is what is seen to generally make a lot of difference in powder. Basically because having more width makes a ski have a larger base area, this decreases the pressure put into the snow through the base, and makes you float better in powder. Which is why powder skis are often very wide. How wide a ski is also effects how easy it is to apply pressure through the edges though, with it being harder to create edge pressure on a wide ski. This means that wide skis are generally not as good in icy condition where edge pressure is very important. The current trend is for manufacturers to make allround skis a bit wider so that they are better in powder, but not so wide that there is any major effect on their icy handling abilities.

Length

The length of a ski makes many differences too. One way some people look at it is that the better you are the longer the skis you want. This is not completely true though, as with the modern carving skis the length will need to be matched with what you want to use the skis for. Generally the longer a ski is the more control it has at higher speeds, but because of the extra length it will be harder to turn. There are skis on the market that have extra pieces of metal stuck to the base near the tips of the skis which are supposed to give you more control at high speeds without needing to make the skis longer, quite how effective they are though, I'm not sure.

Weight

Heavier skis are harder to throw around, but do stick to the snow better giving more control over the edges. This is why most racing skis are quite heavy. Beginners skis tend to be lighter as they need to be moved around easily, the same with freestyle skis, as they need to be able to spin with as little effort as possible. Most skis though fall into the all-round category and are not too light but not too heavy either.

Types of Ski

Here are a few styles of ski with descriptions about what makes them good for these styles.

Slalom Race Skis

Slalom race skis have a relatively small radius typically about 12m, they are stiff for good edge control, and generally are shorter compared to the other types of ski. They are also very heavy so that they stick to the snow allowing the edges to control them.

Downhill Skis

Downhill skis have a very larger radius, as the turns they make are very large, and are very long (typically over 2m) for control at very high speeds. You can not really buy skis like this in shops as they are for racers only, and need a cleared piste because of the speeds used.

Freestyle Skis (Twin Tips)

Freestyle skis generally have tips at the front and back (twintips) so that they can be skied backwards almost as well as forwards, they are normally quite light so that they are easier to spin etc, and are flexible so that they are forgiving on landings and when mistakes are made. The radius is generally about 18m.

Powder Skis

Powder skis are normally quite wide and quite long so that they have a large base area, This makes them float above the snow better. They normally have a large radius although it is not really used in the powder, and are generally quite flexible to allow the ski to bend and make short turns, although the flex can vary quite a lot between skis.

All-round Skis

All-round skis are the most common type of ski. They generally have a radius of about 16 to 20m which is in the middle of the range. They are reasonable stiff but not as stiff as a racing ski. They are a bit wide but not as much as a powder ski, and the length can vary, but generally it is in the middle of the other styles again. These are the kind of skis that most people use as they are good for all types of skiing, but not amazing at any. For most skiers though, these skis are as good at the each type of skiing as the skier is.

Beginners Skis

Beginners skis are generally short so that they are easier to turn, more flexible so that they are more forgiving, and not too heavy. The radius can change but it is normally about 16m or so. The edges on these skis are not too sharp either as they don’t want to catch too easily.

The information here is for alpine skiing, there are other not so common types of skiing as well, including telemarking, and crosscountry skiing. I plan to put small sections about these on the site in the future, so that people can familiarise themselves with them as well.

Move on the the Ski Bindings section.