MULTI RADIUS OR TRIPLE RADIUS
It pops up often lately, concepts like ‘multi-radius’, ‘triple radius’, or ‘3d radius’. But what exactly is it? And is it really something or just marketing terms.
First things first, it is important to understand basic terms like sidecut and radius.
Sidecut and radius
Let’s start with the sidecut or waistline of a ski. It’s determined by tip (widest part on top of the ski), the waist (narrowest part underfoot), and the tail (the widest part at the bottom). The sidecut is always indicated by three numbers mentioned on the ski. For example122-68-104 for a slalom ski. These dimensions also determine the sidecut radius.
But what exactly is the radius of your ski? If you continue the line of the sidecut, you’ll get a circle. The radius of this circle is equal to the sidecut radius of the ski. We always express it in meters. For example 12 meters for slalom and 19 meters for a consumer giant slalom.
The sidecut radius published in this way by the manufacturer is always the biggest radius possible when the ski is carving, not the smallest as many people think. For example, put the ski flat on the snow and push it forward, it will go straight forward. Put the ski on the snow and put it 1° on edge and move forward. It will carve a circle equal to his radius. (I will save you from the mathematical formula of it 😃).
Can we make short carved turns with a giant slalom ski? Sure we can! Two important factors can influence the radius on snow. Edge angle and bending of the ski. The more we do this, the smaller the radius becomes.
Once we understand all the above, we can move on to the multi or triple radius story. Manufacturers are always looking for new technologies that help the customer. Processing multiple radius in one sidecut is one of them.
The idea is quite simple. With less pressure, the ski will automatically use the biggest radius. With more edge angle and pressure/bending, the radius will get smaller. The picture above is a good illustration of how it works. But how does it work in practice? If you are cruising relaxed and you keep weight above your feet, the ski will make nice big carved turns. If you push the gas pedal down (put it more on edge and bend it more), ski more dynamic with fore/after balance, it will carve short turns.
Conclusion: actually every ski is a multi-radius ski because this movement works always. But technology helps to make it much easier. More comfort, less effort, and better control.
Confusion and different names
Brands use different names for this technology. The biggest deception is the name “multi-radius” or “multi-turn”. In piste skis, there are skis for two pronounced types of turns. Slalom turns (11 up to 13-meter radius) and giant slalom turn (18 up to …). Everything in between they call “multi-turn”, medium turns, cross ski, supercross, X turns…here is the catch. They often have real multi-radius technology.
The real deal, for example, is used by Völkl with their “3D radius” or the “Triple radius” by Fischer. In a future article we will give an overview and explanation of the most commonly used abbreviations of ski type indications like sl, slx, sc, gs, rc, x,… and are they using this technology or not.