Selecting the right cross country skis is crucial for performance and enjoyment on the trails. For classic skiing, especially with waxable skis used in groomed tracks, understanding ski sizing is essential. These skis are designed for two main functions: providing grip during the “kick phase” to propel you forward and offering smooth glide in the “glide phase.” While proper kick wax application is vital for waxable skis, choosing the correct ski size is the foundational step for optimal performance.
To begin determining the appropriate ski size, resources like the Fischer size chart are excellent starting points. These charts often suggest ski lengths based on your weight. For example, someone weighing around 71kg (approximately 156 lbs) might find that a 197cm “stiff” ski and a 202cm “medium” flex ski are recommended lengths. Beyond length, understanding ski flex is equally important. A key metric for flex is the FA number.
The FA number essentially indicates the stiffness of a ski. It represents the force, measured in kilograms, required to compress the ski to 0.2mm when pressure is applied at the midpoint. This measurement simulates the force exerted by a skier’s weight on the snow. Since skiers apply pressure through the ball of their foot, rather than the toe, the FA number is determined by measuring the force needed to close the ski at that specific point.
Generally, for waxable classic skis, a good starting point is to look for skis with an FA number that is approximately half of your body weight in kilograms. For a 71kg skier, this would suggest an FA number around 36. Ideally, the ski should fully compress at around 55% of the skier’s weight when pressure is applied at the ball of the foot. For our 71kg skier, this translates to a closing force of about 39-40 kg. Experienced and stronger skiers who possess excellent technique may prefer slightly stiffer skis. Conversely, skiers who are newer to the sport or less technically proficient might benefit from skis with a softer flex, indicated by a lower FA number. The beauty of waxable skis lies in their adaptability; you can fine-tune the grip by adjusting the thickness of the kick wax to match your weight and snow conditions.
When selecting skin skis, the FA number recommendation shifts slightly. Aim for an FA number that falls between 58% and 68% of your body weight. Skin skis, with their integrated grip, perform best with a slightly stiffer flex compared to waxable skis. 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, particularly for beginners or in challenging snow conditions.
For a deeper dive into ski flex and its impact on your skiing experience, explore resources like our detailed guide on Understanding Ski Flex. Choosing the right cross country ski size and flex is a crucial step towards maximizing your performance and enjoyment on the snow.
