Choosing the right size cross-country skis is crucial for both performance and enjoyment on the snow. For classic skiing, especially with waxable skis, the ski’s interaction with the snow during the kick and glide phases is heavily influenced by its length and flex. This guide will walk you through understanding how to select the appropriate ski size, focusing on length and flex considerations for waxable, skin, and crown classic skis.
When looking at waxable classic skis, remember they need to perform two main functions: grip the snow for propulsion during the “kick phase” and glide smoothly during the “glide phase.” While kick wax is essential for grip, the skis themselves must be compatible with waxing. Referring to sizing charts, like the Fischer chart for length, is a great starting point. For example, someone around 71kg might find suggested lengths of 197cm (stiff) and 202cm (medium).
Beyond length, ski flex is a critical factor. Ski flex is often indicated by an FA number. A general rule of thumb for waxable skis is to look for an FA number that is approximately half your body weight in kilograms. For a 71kg skier, this would suggest starting with skis around a 36 flex. The FA number represents the force needed to close the ski to 0.2mm when pressure is applied at the ski’s midpoint. However, since skiers apply pressure through the ball of their foot, a more practical measurement considers the force needed to close the ski at that point. Ideally, you want a ski that closes at around 55% of your body weight when pressure is applied at the ball of the foot. For our 71kg skier, this translates to a closing force of about 39-40kg.
It’s important to note that these are starting points. Stronger skiers with refined technique might prefer slightly stiffer skis. Conversely, those still developing their technique may find softer skis, with a lower FA number, more forgiving and easier to manage. One of the advantages of waxable skis is the ability to fine-tune grip by adjusting the thickness of the kick wax to match your weight and snow conditions.
For skin skis, the selection criteria are slightly different. Due to the inherent grip provided by the skin, skin skis generally require a slightly stiffer flex. Aim for an FA number that is about 58-68% of your body weight. Crown skis share similarities with skin skis in terms of flex considerations. Stiffer crown skis tend to be faster, while softer crown skis make accessing the kick zone easier.
To deepen your understanding of ski flex and its impact on your skiing experience, exploring resources like a comprehensive guide on ski flex can be beneficial. Choosing the correct XC ski size, encompassing both length and flex, is a foundational step towards better performance and more enjoyable time on the trails.
