Imagine a large circle, say 50 feet across. Mark off a 5-foot section of the circle. You have a line that is curved slightly. Now imagine that line is one side of a ski. When skiers tip the ski sideways so that the edge is in contact with the snow, the ski will turn along a path that matches the circle.
That's the simple answer to how a snow ski works.
Top Rossi Rep Deno Dudunake has a more technical explanation, that involves three things that come together when a ski turns.
"First there's the pitch of the terrain, from flat to steep. Second, there's the mass of the skier sitting on top of the skis. Third, there's the geometry of the ski itself. What happens with the mass and the geometry of the ski, or tool, is what creates the turn. When skis were straighter, with minimal sidecut, skiers would go up and down, lifting and dropping, weighting and unweighting, to create the reverse camber - or curve - that made the ski turn, and allowed for the rebound. There was timing involved, as well, and a rhythm, that all combined to make the tool turn. The skis we are making today have much more sidecut, so skiers have replaced most of the up and down motion with side-to-side, or lateral, pressure. Tips and tails of the ski are wider than the middle, and both ends carve the ski into the turns, so skiers keep their mass much more centered on the skis," Dudunake says.