Skip to content

Truth In Ice: Fore/Aft Pressure

6th in a multi-part series on skiing/snowboarding on hard snow.

Deliberate fore/aft pressure modulation allows the athlete to better manipulate the relationship between their base of support and their COM. Through refinement of this relationship, the athlete has yet another means of maximizing available edge grip and arc stability on harder surfaces.

Fore/aft pressure distribution determines where along its length the gliding platform has the deepest ‘bend’ once the platform meets resistance. This can effect the shape/duration of the turn arc, and how the tail end of the platform will follow the front end through that arc. This principle is more important on hard surfaces where the platform has less engagement. On softer snow the platform sinks slightly, forming a larger ‘shelf’ to support the athlete/platform system. On harder snow this shelf may be only marginally wider than the width of the edge itself. If fore/aft pressure is poorly managed while on harder snow, the platform can very quickly go from stable to unstable, as the narrow shelf provides very little resistance to washout.

The simplest way to think of fore/aft pressure is in terms of ‘which foot is bearing the most weight’ (on a snowboard) or ‘which end of the feet are bearing more weight’ (on skis). If rider weight is biased toward either end of the footing, the concentration of pressure will be biased toward that end of the respective platform as well.

On a snowboard, the ‘sideways’ relationship of rider to platform defaults more weight to the front foot heel on a heelside turn, and more weight to the ball of the rear foot on a toeside turn.

This default leads to skidding/washout problems on the heelside turn, and excess speed/edgelock on a toeside turn. If you address the weight distribution disparity, the board will bend more evenly, and these tendencies can be reduced or eliminated entirely.

In alpine skiing, a combination of internal boot ramp, forward lean, front cuff leverage, and binding delta often directs too much bend toward the shovel of the ski. This is why many recreational skiers present with a ‘back of center’ posture. They have moved rearward to achieve a semblance of stability.

Understanding these defaults empowers an athlete to address the specific inputs leading to errant platform behavior. Sometimes it’s just a matter of changing practice. Sometimes it’s necessary to address equipment configuration in order to change practice, or to facilitate a known process that isn’t quite delivering.

To carry the arc of the turn with an even bend, pressure should be concentrated slightly ahead of the dynamic center of the platform. This may not be the geometric center, nor should this necessarily be located directly under the front foot. It will vary from platform to platform, and from rider to rider. When pressure is concentrated in this location, the bend in the platform can be maintained and the arc sustained as long as momentum prevails.

When pressure concentration moves back of this location, the platform will attempt to rebound forward, out from under the athlete along the projected glide path, . This is readily apparent when you watch a novice rider make a toeside turn on a board that is too stiff; the board ‘locks in’ and then walks right out from under them.

When pressure is concentrated too far forward on hard snow, the tail end of the platform may try to overtake the front end, leading to skid and/or spinout. On soft snow, the front end may plow, stall, or stop entirely, causing the rider to pitch forward abruptly, or to land suddenly on the snow to the inside of the turn.

At turn initiation, rising pressure is usually felt through the front foot, as the front end of the platform seeks a new path, and resistance of the athlete’s momentum begins to bend the platform. Assuming that platform is sized correctly for the athlete and the end purpose, and that the bindings are located in a suitable location, the athlete should not need to ‘move’ to the front foot in order to initiate or maintain the turn. Instead of ‘moving forward’ to create pressure, the pressure is ‘coming to’ the front foot as the platform bends. The athlete then maintains/augments/distributes the bend in the board as needed. (In alpine skiing, the forefoot/boot toe is analogous to the front foot in snowboarding).

Through the body of the turn, pressure should be applied/maintained with both feet. If the boot/binding/board configuration has not been optimized, it may be necessary to bias noticeably to one foot or the other in order to achieve consistent edge hold and arc radius control. Biasing may work in the short run, but over time one leg will be doing more work than the other. Too much effort/fatigue will impair the feedback loop, which in turn will reduce input accuracy. Sharing the load, so to speak, can reduce effort, and enhance input quality.

As the turn nears completion, weight should fade rearward, coinciding with a decrease in edge angle as a means of releasing the board from its arc. If weight is not moved rearward, and if the edge angle to the snow does not decrease, the board should continue as before until momentum is consumed.

On softer packed snow, these principles may not be obvious, simply because that surface is more forgiving, and provides a much larger margin for error. On harder snow, greater input accuracy is required. That accuracy will pay off in terms of grip, stability, and maneuverability.

Next: Line change.

Published inUncategorized
%d bloggers like this: