May The Force Be With You: Physics of the Turn

What are the forces in a turn that allow skiers to lean over like they were in some sort of fun house slanted-wall room? The major three major forces are gravity, centrifical and centripital force. Gravity's effects are obvious as it pulls you down a hill, Centrifical on the other hand is trickier. This apparent force feels like it is pulling straight out from the arc of the turn, but actually it isn't. Think of a car making a turn on ice, if it slips and breaks off the turning arc, it will skid not straight out , but at a tangent down and out.

In order to effectively use centrifical force, you need to angulate more near the bottom on the turn instead of the center of the turn. Picture the capital C representing the turn. If the forces of the turn a greatest at the bottom corner of the C, then the body has to braced strongest against the force at this point. Simply speaking, the body has to be in the lowest or in a flexed position at the last corner of the representing C shaped turn.

Centripital force pulls you to the inside and counters the Centrifical force, thereby keeping you in balance. In fact, the force would pull you inside into the center of the turn, if centrifical force wasn't there. This centripital force is a real force because you must turn your feet to create it; otherwise, you would be going straight. You will ride a fine line as you balance between the two forces. As the Centrifical force increases with speed and shape of the turn, the applied centripital force must be increased as well. You will increase this force by dropping the hip more to the inside of the turn and steering the feet more across the falline.

The best skiers can maintain a strong sense of balance while the forces build and become great. It is at this point that the balancing point becomes very small and only experience will tell you just how much to drop the hip and steer the feet. One way to demonstrate how to counter the forces in the turn is to play a game of tug'o war with a friend. Use a set of ski poles as the rope and try to pull the other skier over his skis toward you. As you pull, you will find yourself getting into a lower or flexed position. This pulling force is exactly the same as centrifical during the turn. The lowering of the body, while keeping the upper body facing towards the pull is the most effective way to counter the force.

Alpine Skiing School section in english version of WWW.SKI.BG is based on
"A Guide To Becoming An Expert: From First Time To A Lifetime"
by John Mukavitz Copyright © 1998