Sidecut radius
Also called sidecut, turn radius
The radius of the arc the edge would scribe if extended into a full circle, in meters. Short radius turns quick, long radius runs stable.
Look at a board from above and the edge is not straight. It curves inward from tip to tail, widest at the ends and narrowest at the waist. Extend that curve into a full circle and its radius is the sidecut radius, printed in meters on the spec sheet. It is the board's preferred turn shape.
What the number means
Tip the board on edge and press it into the snow and the sidecut bends the board into an arc. The deeper the sidecut, the tighter the arc. Most snowboards sit between 6 and 9 meters. Around 6 to 7 m the board wants short, snappy turns and darts edge to edge. Around 8 to 9 m it draws longer, calmer arcs and holds a line at speed without feeling twitchy. Skis span a wider range, from under 13 m on a slalom-derived carver to 25 m and up on big-mountain shapes.
The radius is a preference, not a cage. You can force a 9 m board into a tight turn by skidding it, and you can open a 6 m board into a long arc. But the board fights you a little each time, and at speed a deep sidecut has a hooky habit: the edge wants to keep tightening the turn when you would rather it ran straight.
Multi-radius sidecuts
Many boards now blend two or three radii along the edge, tighter near the center and longer toward the ends, under names like progressive or asymmetric sidecut. Some add texture to the edge itself, the best known being Magne-Traction's wavy serrations for hard-snow bite. The printed number is then an average. Useful for comparison, but read a measured review before you trust it.
Choosing by radius
- Tight trees, moguls, slow-speed play: shorter radius, roughly 7 m or under on a snowboard.
- Groomer carving at pace, open terrain: 8 m and up, with camber to keep the long edge biting.
- All-mountain: the 7 to 8 m middle, which is where most boards live for a reason.
Sidecut works together with effective edge: the radius sets the shape of the turn, the effective edge sets how much steel holds it. A short radius on a long effective edge carves tight and grips hard. That combination is what a dedicated carving board is.