Waxing skis and general ski servicing used to be alien to me. It was like getting an MOT for my car; I know I need to get it done, but not really sure why! Over the years of servicing skis I have gained knowledge into the benefits of waxing skis and the tangible results on the snow. I’ll outline the basics below.
The mechanics of sliding
The main forces involved in sliding are downward forces, friction from and air resistance. Velocity is created from the skiers downward force, ie their weight on a slope. Friction is generated between the ski base and the snow causing a reduction in speed. The other speed reducing factor is air resistance on the skier; this is why we see ski racers weaning tight fitting cat suits to minimise this resistance. Wax plays the role of acting as a lubricant to minimise base friction!
Snow types & wax
If you have taken more than one ski trip you have probably experienced different snow types. Different ski waxes help to tackle different conditions. Early and late seasons generally produce ‘wet’ snow conditions as temperatures are above 0°C and snow melts. High altitude or northern ski resorts (US, Canada, Scandinavia etc) produce hard pack and icy conditions. The snow conditions create either ‘wet’ or ‘dry’ friction with the ski base. An example of wet friction sticking two panes of glass together with water. Dry friction is the feeling of rubbing your hands together. To help create the best ski experience, specific waxes help to lubricate the wet or dry frictions cause by the snow.
Wax as a lubricant
The lubrication affect of waxes is akin to a sliding a deck of cards sideways. Wax helps the ski slide over the snow and leave the sliding cards behind. This is the case until you run out of cards and need to rewax the skis. The ease of sliding the ‘cards’ depends on the internal friction between them. Softer waxes, used in warmer conditions, have a lower internal friction, and harder waxes, for colder conditions, have a higher internal friction.
Different waxes for different snow conditions
On the face of it, softer waxes should always be faster, as it has lower internal friction. However there is another friction to consider, that between the snow an the last wax ‘card’. Hard snow crystals, found in colder conditions, are able to penetrate the wax, increasing friction between the snow and wax. Imagine sticking a nail through a pack of cards. For optimal conditions, the wax must be harder than the snow, to prevent it from penetrating the wax. To maximize speed we need:
Internal Friction + Wax/Snow = the lowest figure possible
What are the results?
The below results are taken from a study by Dominator Waxes.
- Cold snow and very wet snow are the slowest, the fastest snow is at around
- Snow friction increases rapidly with colder snow, skiing on snow at -40c is like skiing on sand
- Waxing increases speed 6% to 18% depending on snow temperatures, the higher effects are on very cold and very wet snow
Here are some results of ski wax speed tests from Ski Wax Europe.
On the face of it 0.3 sec may not seem like that much, but this is only over a 10sec run. For skiers covering 30km+ per day, there are some big gains to be had by applying the right wax.