The Ski Test Guys

The temperature is forecast to be 24 deg at the start time of 10:00 rising to 26 degrees at noon.  At these temperatures a warm, soft wax like Swix CH8 or equivalent will be the best choice.

How the forecasts are made:

How to read this chart:


We can calculate the estimated time difference to complete the race from knowing how the wax coefficient of friction changes during the day as the temperatures change.   The chart to the left is the difference in finishing times using different waxes (for a skier who completes the course in about 2 hours).

How to read this chart:


The time of day is shown on the bottom horizontal axis with the race start time the first data points plotted.  The forecast air temperatures are shown with the black line and the Y-axis on the left.  The estimated friction of different waxes at a particular temperature are shown on the Y-axis on the right (lower friction = a faster ski).  

2019 Sisu Ski Fest

The forecast is for the air temperature to be 24 deg at the start time of 8:30 rising to  34 degrees at noon.  At these temperatures a warm wax like Swix CH8 or equivalent will be the best choice for all waves.

2019 Seeley Hills

2019 Birkie:

How to read this chart:


The time of day is shown on the bottom horizontal axis with the race start time the first data points plotted.  The forecast temperatures are shown with the black line and the Y-axis on the left.  The estimated friction of different waxes at a particular temperature are shown on the Y-axis on the right (lower friction = a faster ski).  

By combining the data we acquired on  Ski Wax Friction vs Temperaturewith a weather forecast of Temperature vs Time of Day with a race course profile and the time of day skiers are on the course and some physics and exercise physiology methods (Moxnes, John F., Øyvind Sandbakk, and Kjell Hausken. "Using the power balance model to simulate cross-country skiing on varying terrain." Open access journal of sports medicine 5 (2014): 89)  we can make a pretty good estimate of the effect different waxes will have on the time to complete a ski race.


The forecasts are only for the waxes we have characterized.  Many other waxes are available and will perform differently.  Use this data as a guide to understanding the effect of wax hardness vs temperature. 

How to read this chart:


We can calculate the estimated time difference to complete the race from knowing how the wax coefficient of friction changes during the day as the temperatures change.   The chart to the left is the difference in finishing times using different waxes.  Swix CH8 is the fastest in these simulations (zero on the time lost chart) and Swix HF8 is slightly slower.  A blue wax would be about 2 minutes slower for elite wave skiers and 5 to 9 minutes slower for a wave 6 skier.

The temperature is forecast to be 24 deg at the start time of 10:00 rising to 28 degrees at noon.  At these temperatures a warm, soft wax like Swix CH8 or equivalent will be the best choice.

How to read this chart:


We can calculate the estimated time difference to complete the race from knowing how the wax coefficient of friction changes during the day as the temperatures change.   The chart to the left is the difference in finishing times using different waxes (for a skier who completes the course in about 2 hours).

How to read this chart:


The time of day is shown on the bottom horizontal axis with the race start time the first data points plotted.  The forecast temperatures are shown with the black line and the Y-axis on the left.  The estimated friction of different waxes at a particular temperature are shown on the Y-axis on the right (lower friction = a faster ski).  

Ski Wax Performance Forecast for Upcoming Events