Counter-intuitively, despite typically cold conditions encountered while snowboarding, friction alone heats your snowboard enough to return snow to its liquid state (water). Tis also partially explains why boards have a more difficult time gliding when the snow itself is extremely cold.
THE BOARD-TO-SNOW INTERACTION: FRICTION Friction, in this case, is the snowboard moving in the snow. On-snow friction is generally thought to be caused by two resisting forces. Te first is the resistance caused by the plowing action of the board’s tip and the second is the snow compressing under the board.
Being able to control the board by making it perform in differing ways enables riders to dictate how much friction actually occurs. Fundamentally, a snowboard can slip, skid, carve, or slide. All of these produce a different reaction with the snow. Slipping is when the board travels along its side in a direction that is perpendicular to the fall line while being tipped on edge (i.e., a sideslip). Skidding is a combination of the board moving along its length and its side while on edge. Carving is when a board is on edge, with tip and tail passing through nearly the same point in the snow throughout the turn. Sliding is when the board travels flat and along its length.
FORCE
More accurately, the snowboard rides “in” versus “on” snow when a rider is making turns. It is the snowboard’s interaction in the snow that is responsible for a lot of the amazing exhilaration you and your students feel while riding. Sliding downhill on the snow is fun in and of itself, but to change direction is extraordinary. A force is a push or pull that changes an object’s position or places an object into motion. Tis is exactly what the rider wants to do with the snowboard.
When making turns on a snowboard, direction change is only possible if the snowboard is in the snow or strikes against an object. Tis is easiest to see with a carved turn. Te trench “carved” out by the snowboard creates a bank for the rider to balance against. Tis bank essentially pushes back on the snowboard deck, helping the board turn. Te force against the snow, or, more correctly, the force pushing back against the snowboard, is what is needed for the board to turn and proceed in a new direction.
FIGURE 1.1: Centripetal Force
CENTRIPETAL FORCE Centripetal force from the snow is a center-seeking force and is essential for the snowboard to change direction. Without a rider creating a centripetal force, there can be no turn. Tis is most obvious in a pure carved turn, but what about in the abrupt edging and extension movements of a powder slash? While there is no single trench left in the snow from the slash, there is still
22 AASI SNOWBOARD TECHNICAL MANUAL ORBIT AXIS
CENTRIPETAL FORCE
VELOCITY =
Angular velocity, rotational speed
TheSnowPros.org
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