Ski, Structure & Wax: How Equipment Choices Impact Cross-Country Ski Glide Performance

Ski, Structure and Wax

A meta-analysis based on Budde, Rick, and Adam Himes: “High-resolution friction measurements of cross-country ski bases on snow.” Sports Engineering 20.4 (2017): 299–311


Dan Kuylenstierna
2025-04-15

Among cross-country skiers, it is widely understood that ski type, base structure, and wax all influence glide performance. A common belief is that they affect glide in exactly that order: first selecting a ski with the correct pressure zones, then choosing the right structure, and finally selecting the appropriate wax for the day. Despite this commonly held view, there is surprisingly little documentation that confirms the relationships between these factors. It also raises the question of how one could scientifically validate such a statement. Testing would require numerous ski pairs and multiple preparation methods. It is also not as simple as preparing two different skis identically—since it could be the case that each ski performs best with a different wax.

Therefore, this text does not attempt to determine the exact relative impact between the three factors—ski, structure, and wax. Instead, the purpose of this review is to discuss how much these factors combined can influence the outcome of a cross-country ski race.

Our analysis is based on two research studies1,2 and a series of simple calculations3 to estimate how glide affects race time under given environmental conditions and athlete capacity. We also discuss how glide can be measured and what level of precision is necessary to ensure competitive equipment. Scientifically, “good glide” is defined as low glide friction. Several studies have shown that friction between ski and snow can vary significantly depending on conditions. Typical values range from µ = 0.01 to µ > 0.06, with the lowest values occurring on transformed snow just below 0°C, and the highest on very cold dry new snow or very wet suction-like snow. Glide friction also varies with speed4, although this comparison does not explore that factor in depth.

Study [2] presents long-term outdoor measurements in varying conditions. Table 1, borrowed from the article, shows how friction changes depending on ski choice, structure, and wax. The study compares a cold-structure ski with a warm-structure ski. Both skis are prepared with the same wax at each test occasion and are compared to a reference ski with a factory base structure. The reference ski is always prepared identically with the same wax (REX Blue). At first glance, Table 1 shows no obvious pattern—just like real-world race testing, the measured values vary substantially and the ranking between skis shifts from test to test.

The highest friction was measured at -23°C on new snow for the factory-structured skis, with µ = 0.035. The lowest friction was measured for the warm-structure skis at -1°C on transformed snow, with friction as low as µ = 0.0053. To understand what these values mean in practice, the performance impact is roughly 30–35 seconds per kilometer—or 5–6 minutes over a 10 km race5. This reinforces what every skier knows: race time alone is a poor measure of performance in cross-country skiing.

A more relevant question is how much ski choice can influence performance under fixed environmental conditions. Based on the friction coefficients in the table, the largest difference between two ski pairs in the same conditions was 1 minute and 48 seconds over 10 km—between the warm-structure skis and the factory-structured skis in -23°C new snow. Another interesting observation is that the cold-structure skis in this very cold condition had higher friction than the warm-structure skis, despite being waxed identically. From this, we conclude that the combined effect of ski, structure, and wax can influence up to 2 minutes over 10 km for an elite skier—and even more for a recreational skier.

The next step is to break down the data to see how much influence comes from structure and how much from wax. Since the warm- and cold-structure skis were consistently waxed with the same wax, the difference between them can be assumed to depend on the structure and ski alone. The article provides no information on whether the warm skis differ from the cold skis in any way other than structure. The data shows that the cold-structure skis are on average just under 2 seconds faster than the warm-structure skis over 10 km, but with a standard deviation of about 15 seconds—meaning that choosing the right ski pair for the conditions is critical. The largest difference occurred in transformed snow at +2°C, where the warm-structure skis were 35 seconds faster than the cold-structure skis.

The next question is the influence of wax. When warm- and cold-structure skis are waxed with the same wax as the reference skis (REX Blue), the warm-structure skis have roughly the same friction as the factory skis, while the cold-structure skis have about 7% higher friction, equivalent to roughly 11 seconds over 10 km. Figure 1 plots glide friction for the three structures against temperature. All skis show lower friction in warmer temperatures, but the cold-structure skis lose the least performance as temperature drops, while the warm-structure skis benefit the most when temperature rises.

Fig. 1. Friction vs. temperature for skis with identical wax but different structures.

To better understand the impact of wax specifically, we can compare the structured skis with other wax types against the reference skis, which consistently use the same wax. In every test case, skis with dedicated waxes show lower glide friction. When analyzing friction and race time versus temperature more closely, it becomes clear that each wax performs best within its optimal temperature range, as shown in Figure 2. This effect is especially visible for CH8 (a clear warm-snow wax) and CH4 (a clear cold-snow wax). As expected, no trend appears for REX Blue since the reference skis use that wax. The trend is also weak for CH6, which is similar to REX Blue. HF8 is not included due to insufficient data.

Fig. 2. Difference in glide friction for each wax type vs. temperature.

1 Swarén, Mikael, et al. “Validation of test setup to evaluate glide performance in skis.” Sports Technology 7.1-2 (2014): 89-97.
2 Budde, Rick, and Adam Himes. “High-resolution friction measurements of cross-country ski bases on snow.” Sports Engineering 20.4 (2017): 299-311.
3 Hur mycket tjänar skidåkare på bättre glid? | SKISENS
4 Auganæs, Sondre Bergtun, Audun Formo Buene, and Alex Klein-Paste. “Laboratory testing of cross-country skis–Investigating tribometer precision on laboratory-grown dendritic snow.” Tribology International 168 (2022): 107451.