210 Enhance the short turn
Cross-under and rebound
In order to make an effective short turn, it is necessary to move the snowboard from one edge to the other and back again in a fairly short time span. This requires that edging movements must be derived from the feet and knees more so than from the hip and torso. In this context, the torso becomes a stabilizing mass, which does not move much, with the board and lower extremities moving underneath.
The term cross-under refers to the fact that the board moves under the center of mass as it is tipped from one edge to the other. For effective cross-under to take place, it is necessary to develop some sense of separation of upper and lower body masses, so that the stuff that needs to move can move quickly, and the stuff that does not need to move is not brought along for the ride.
To facilitate cross-under, begin on a reasonably flat pitch, and, with an excessively flexed stance, rock the board from edge to edge. Use the feet and knees, and try to keep the torso facing down the fall-line (or simply an angle to the fall line that represents your neutral posture on the board). The board will not move too far out of the fall-line, which means that it may be necessary to stop and start in order to avoid going too fast.
The second requirement for a short turn, or for more effective cross-under, is the use of rebound as a motive force. Rebound is the release of energy from a board that has been bent into reverse camber and where this energy has not been lost to friction. Developing a sense for the potential of rebound involves first identifying what an elastic board feels like. This can be accomplished by making what are called ‘smiley faces’ on a fairly steep pitch. The rider should tune in to the sensation of the board lifting them back up the hill with each arc, and the pressure that builds underfoot as this occurs. Once familiarity with the sensation has been established, the goal is then to build and release pressure so that the board begins to feel like a watermelon seed squeezed from between two fingers at the end of each turn.
The end product should be edging movements originating in the feet. The board will be propelled from one edge to the other and from one side of the rider to the other with its own rebound. It is very easy to make timing mistakes when learning how to harness rebound energy on a short turn, so focus and speed control are important.