Originally, skiboards were defined as having a length less than 1 meter (39.3"). This was so that lightweight non-release bindings could be used in competition. The working assumption (and this has proven to be true over time) was that competition riders could safely use fixed bindings with skiboards less than one meter in length. With the advent of the Spruce release binding system in 2003, recreational riders could now ride without fear of injury and skiboard designers could experiment with longer skiboards without compromising rider safety. This has led people to ask: "When is a skiboard not a skiboard?"

The simplest answer to this question is that a skiboard is a skiboard because it has a very small turn radius compared to all other common snow sliding devices. This is true whether the skiboard is a very short 62cm "Blade" or a 130cm longboard. It is this small turn radius that makes turn initiation easy and allows the rider to make very sharp turns when they are needed, almost without thinking.

Typical skiboards have a turn radius of 4.5 to 7.5 meters (15 to 25 feet). Short skis that are 120cm to 130cm have a turn radius of roughly 11 meters. "Shaped" skis in the lengths commonly used by adults today have a turn radius of 13 to 15 meters. Snowboards are in the range of 8 to 9 meters.

The short turn radius of a skiboard implies that the board must have a deep sidecut. That is, the width of the tip and tail of the board is much greater than the waist resulting in more of an hourglass shape than is present in traditional skis. When initiating a turn, it is this deep sidecut that starts the board turning with very little conscious effort on the part of the rider.

So, skiboards are characterized by their deep sidecut compared to traditional skis. As skiboards get longer, their side cut must get deeper in order to have the same turn radius. So, for example, a 100cm board with a turn radius of 7.0 meters has a sidecut of about 23 millimeters (the waist of the board is 23 millimeters smaller than the width of the tip and tail). A 120cm board (20% longer) has to have a sidecut of about 36 millimeters in order to have a 7.0 meter turn radius. That's a 56% increase in sidecut for a 20% increase in length.

There is no reason that skiboards cannot be made in any length. However in very long lengths (comparable to traditional skis) they look strange as the sidecut is extreme. In addition to this, experimentation with longer length skiboards on snow shows that skiboards in a range of lengths from 120cm to 140cm have more than adequate stability and that they are fully comparable in that respect to traditional length skis when ridden with proper technique.

So, why aren't all skiboards longboards? For competition, shorter boards with lightweight fixed bindings remain the optimum combination. It should be noted though, that some Pro riders are using boards as long as 110cm as they enjoy the added stability. For recreation, longboards provide stability for high speed riding and for riders who are taller and heavier. This stability comes at the expense of quickness in starting a turn since the "swing weight" of longboards is higher. (Imagine twirling a 3 foot baton compared to a 10 foot baton.)

Skiboarders should count themselves lucky that they can ride on a range of different length skiboards all of which give them great performance