Here are some terms that will be helpful in discussing your ski. Bear in mind the descriptions below are more information than you need to know when discussing a ski design with us. The relationship between all these design elements is complex. This section is meant to give you an overview of the elements and hopefully be interesting. Just remember, when we are building you a ski, we are the ones who will be incorporating these elements into a ski design. Your only responsibility is to tell us what terrain you want to ski and what you want to accomplish as a skier.
Dimensions refer to the width in millimeters of the ski at three specific points: the tip, the waist, and the tail. So a ski with the dimensions, 135-107-125 is telling you the widest part of the tip and tail (135 and 125) and the narrowest point of the waist (107). The dimensions give you insight into the sidecut and taper of a ski.
This is the part of the ski’s edge that makes contact with the snow. It is usually just inside of the widest dimension points of the tip and tail. For a non-twin tip ski this is usually 12% less than the ski’s length. However, for twin-tip skis it is often about 16% less than the length.
Camber is the amount a ski arcs upward from a flat surface. A ski with 5mm of camber that is placed on a flat surface will be 5mm off the surface at its highest point (usually under the boot).
This is one of the most significant trends in ski design today. The terminology is still getting worked out, but for our purposes we will define them as such. A rockered ski is a ski that has a reverse camber. That is, if you laid a ski on a flat surface, the tip and tail would rise off the surface with a continuous arc and the ski would “rock” back and forth. Early Rise is when the center part of the ski is flat or even has a slight camber to it but the tip and tail rise up off the surface much farther inward than on a traditional ski. Rockered skis are powder tools and excel in that arena. However, they are less stable on harder surfaces due to the small amount of effective edge. Early Rise skis incorporate the powder performance found in rockered skis while giving you a larger effective edge in harder conditions.
The way we use "taper" has two different meanings;
-One definition is the difference between the tip dimension and the tail dimension. For example, the dimensions 135-107-125 tell us the ski has a 10mm taper (135–125=10). If skiing switch is a goal, a taper of 0-10 works well. If skiing switch is not a goal, a taper of 8+ is good. More taper also allows the tail to sink in soft snow and allows you to smear a turn more easily.
-The other description of taper referes to how far in the widest contact point is in from the overall length of the ski. For example if you compare the Blue Note Carve shape to the Completo shape you will see that the widest point on the Carve is much closer to ends than the Completo. The further into the runnning lenght the widest point is, the smoother the ski will be to both release and engage. This also shortens the effective edge of ski. The further out, the quicker the ski will be to hook up and react. The effective edge is much longer on shapes where the fattest point is close to the ends. This in turn provides a longer gripping surface and more edge grip. Many of our shapes incorporate some type of tip and tail taper to try and find a balance between grip, forgiveness, and control.
Sidecut is generally the radius created by the dimensions of a ski. It is the curve found in the side of the ski. It can be discussed in many ways. The difference in width from the tip to the waist and the difference from the waist to the tail is one way. So in a ski that is 135-107-125, you could refer to the sidecut as 28mm (135-107=28mm) from tip to waist and 18mm (125-107=18mm) from waist to tail. On a fully symmetrical ski the number will be the same. These numbers will give you basic info about how the ski will enter and exit a turn and how deep the ski’s sidecut curvature will be.
The other number used when talking about sidecut is the approximate turn radius of a ski. Each manufacturer will provide a number and this number refers to the size of the curve/arc created by the ski’s dimensions. For example, a ski with a radius of 20 meters is telling you that when the sidecut of the ski is engaged, the ski will approximately follow an arc that is determined by a circle with a 20 meter radius. However, you need to remember these numbers are approximate. Ski sidecuts never have an exact circular radius and most often incorporate several actual radii. Two skis might have the same published turn radius but will actually turn differently. Let’s take an example. A ski with dimensions 112-84-112 and a ski with the dimensions 120-88-112 have the same approximate turn radius of 18 meters. However, the first ski will enter and exit a turn relatively the same because the difference between the tip-waist and the waist-tail are the same. The second ski, though, will have a stronger tip engagement (120-88=32mm as opposed to 112-84=28mm) and thus will enter a turn quicker and with less effort. This will make the second ski feel quicker in its turn initiation and make you think the radius is tighter. Also, if a ski has an early rise or rocker design, you can pretty much throw out the radius number; it won’t give you much information on the turn. This is why it is important to remember these numbers are guidelines, not rock-solid determiners of a ski’s performance.
Flex is the relative term for the stiffness of a ski. It actually should be discussed in three parts: flex profile (or pattern), longitudinal stiffness, and torsional stiffness. The flex profile of a ski is determined by the core profile (thickness of a ski from the side) and it dictates where the ski flexes and bends along its length. Longitudinal stiffness refers to the amount of energy it takes to activate the flex profile and is controlled by the core’s thickness and width and the ski’s composite make-up. Torsion is the ski’s ability (or not) to twist under pressure. If you took a ski and clamped it to a table, then grabbed the tip and twisted, you would be feeling the torsion of the ski. This is determined by the core lamination, thickness and width, and the composite makeup of the ski. The combination of flex pattern, longitudinal stiffness, and torsional stiffness are crucial to a ski’s performance and they play a direct role in how the sidecut of the ski behaves. A ski that is longitudinally stiff but is softer torsionally will straight line through crud but when you get it on hardpack, the lack of torsion can keep a stiff ski from locking in a turn. Likewise, a longitudinally softer ski that is stiff torsionally will hold fast when you engage the sidecut but have a speed limit in crud.