Stiff vs soft skis under your weight

Skis are not stiff or soft on their own. They are stiff or soft for a skier. A ski that feels planted under 60 kg can feel busy under 95 kg, and one that feels like a plank to a light skier can be just right for a heavy one. This page puts a number on that.

Slide your weight up. The solid ski is a stiff, cambered carver, 72 mm under foot. The dashed one is a softer, rockered freeride ski, 104 mm under foot. These two differ in more than flex, so what you are seeing is stiffness plus shape. At 50 kg, the carver’s peak pressure is about 10 N/cm along the edge. At 125 kg it is about 27 N/cm. The freeride ski goes from about 12 to about 33 N/cm. More weight, more pressure, on every ski.

What changes is what each ski can do with that pressure. In the lab, the carver holds along its whole edge on groomed snow at every weight we show. The freeride ski’s tail is marginal at 50 and 65 kg, and slides from 70 kg upwards. Its tip and underfoot still hold. It is the tail, the part with the least load and the least stiffness behind it, that gives up first.

The lab does not simulate vibration, so it cannot show chatter directly. What it shows are the two ingredients the forums argue about: how hard the snow pushes back, and whether each part of the edge still has the grip it needs. An edge that only just holds is one that can let go and catch again. That is how chatter feels, but it is our reading of the numbers, not a measurement.

Weight is only half of it. Your speed, the snow and your balance all change the load. The model uses one skier, one turn and groomed snow, and treats the ski as a beam on elastic snow. It tells you which way things move, not exactly how far.

What to do with that: if you are heavy and your skis feel nervous at speed, you are probably on something too soft or too short for you. If you are light and your skis feel like planks that will not turn, they may be too much ski. Both are fixed by the right ski, not by skiing harder.