October 11, 2007 | Switzerland, | Ski

This is not a trip report, but is might be of interest for the Ski touring crowd. Check it out.

Out there with the right skin (Micro Auer SLF, Davos; translated by Martin Volken)


Proper skin choices can mean substantial energy savings for the skitourer in uphill mode and lets one enjoy the downhill more. Which skin is the right one?

Until now skitourers depended on personal experience values when choosing a new skin. Now the Swiss Institute for Snow and Avalanche science conducted a scientific study about the gliding and climbing properties of climbing skins in different snow and temperature conditions.
Result; the perfect ski does not exist. Field tests as well as lab tests have shown that climbing and gliding properties depend greatly on snow conditions.

Testing in the lab and in the outdoors.


Ski tourers demand excellent climbing properties with a lot of friction and excellent gliding properties with as little friction as possible of a climbing skin. The SLF (Schweizerische Lawinenforschung) tested 8 different skins with plush made of Mohair and Synthetic fibers as well as a Mohair/Synthtic mix. In order to make climbing possible, the fibers have to be attached to the nylon backing parallel to the walking direction. Each single hair is being attached eighter once (v – shape) or twice (w – shape).

In the lab the SLF tested the skins on a tribometer, an instrument that measures frictional forces. This instrument measured frictional resistance of skin samples that were placed on a turning metal ring (see picture). The particular size of the skin sample simulated the pressure that a grown up weighing about 175 pounds would put onto the snow.

The result: The frictional resistance increased generally the frictional resistance. Tests showed however that Mohair and Mohair/Syntetic mix showed consistently better climbing properties in different temperatures than synthetic skins. A correlating analysis further showed that apart from the actual material the plush length is a deciding parameter: the test skins with longer plush showed better climbing characteristics than the ones with short plush. The ranking here remained the same regardless of temperature range measured (-1C or -15C).

Gliding is the problem.

With a trick combination of various skin characteristics ski tourers could choose skins for climbing without having to deal with disadvantages during temperature changes. Gliding properties are more complex. Measurements showed that the gliding resistance at around -1C is generally lower than at -15C. The various data however did not show an analog ranking. Each skin that had top results at -1C, in other words the lowest friction coefficient, ranked second to worst at -15C. A comparison between lab tests and standardized field tests showed principally good overlap.

Mohair or Synthetic skins

Ski tourers have the general opinion that synthetic skins are more suited for warmer snow temperatures (> -3C) and Mohair skins are more suitable for colder snow temperatures (< - 8C). Measurements confirm this notion. Synthetic skins outperform mixed fiber and mohair skins in warm snow temperatures. Conversely mixed fiber and mohair skins outperform synthetic skins in colder snow temperatures.
Naturally the gliding properties do not depend on material alone. Further equally important parameters are plush and or hair quality, the hair length, hair angle to the backing. Short hair coupled with a fine gliding surface have positive results for gliding properties. Skins with a rough surface show especially poor gliding properties in powdery snow. Not only snow temperature, but also snow density, crystal shape and crystal size are further deciding factors. Gliding tests showed that one of the skins showed limited gliding properties in cold powdery snow, but very good gliding property in cold, compact snow.

Defined application areas

A good climbing skin should offer as much friction when you are standing up on the skin and the as little friction as possible during the gliding phase of the stride. For a skin to achieve this, the above described parameters like hair length and type as well as manufacturing style are important. The climbing and gliding properties are furthermore influenced by different snow conditions as well as snow temperature, snow density, crystal size and shape.
Even if the ideal ski climbing skin for all conditions and situations does not exist;
A better definition of the intended application range can aid in the product selection.