Ski Surface Properties

Knowledge of snow and its different characteristics and properties is important when it comes to selecting the sliding surface of skis.

Sliding Friction of Skis

A widely researched subject is the sliding friction of skis on snow, which is important when cross-country skiing. In competitive skiing, it is of utmost importance to choose skis and adapt the topography of the ski base surface to the prevailing snow conditions to minimise sliding friction.

To further improve sliding, the skis are waxed using different products depending on the snow conditions and the properties of the snow in the ski track. In order to be able to choose the most suitable skis, it is necessary to have knowledge of both the snow and the mechanisms that affect sliding friction while skiing.

Properties of Skis that Affect Sliding Friction

Important properties of cross-country skis that affect the sliding properties can be divided into:

• The ski itself (the material properties and the span curve)
• The ski base material and its texture.
• The surface finish and the ski wax.

The Span Curve of a Ski

One important feature of a ski is the rigidity and stiffness along the length of the ski. This is a very important feature influencing the span, i.e. how much the ski will bend under pressure. This, in turn, affects the pressure distribution under the ski as it interacts with the snow.

The span curve of cross-country skis can be measured using different tools. Simply put, the span curve defines the front and rear glide zones of the skis as well as the grip wax pocket when the skis are used for classic style skiing. The desired characteristics of these parameters are different, depending on the properties of the snow, as well as the weight, skills etc. of the skier.

Ski Base Surface

The ski base surface has a texture, which generally is produced by grinding the skis using a grinding machine. This texture can then be further improved using different drilling and filing tools to optimise the pattern with respect to the snow properties in the ski track. These tools can be handheld and have a variety of different structures which can be applied to the ski base by pressing and rolling the tool over the ski base surface.

Cross-Country Ski Wax

The last step in improving the sliding properties of cross-country skis is to apply a ski wax. There is a large number of different waxes which are produced for different snow types. The use of glide wax on skis is controversial and a much-discussed subject. Most researchers seem to disagree on the exact use and the benefits.

Consider

What are the important factors to think about when you are going to buy skis?