byuboundI'm gonna think about it more tomorrow, but my first guess is that skis are thin enough for the tension/compression from the bending force to be insignificant. The more of an object's cross sectional area is further away from the central axis, the greater these forces will be. With a ski, the entire cross section is distributed very close to the x-axis at its center so the tension and compression would be very small. Cool question

****This post was edited on Mar 3rd 2021 at 1:10:36am**

Ok yeah here is a little quick math that would back this up:

Imagine if you are flexing a ski hard, you are creating an arc with a radius of maybe 2 meters (Probably larger but I don't really care to check)

Say our ski has an edge length of like 185 cm, so the arc length would be 185 cm at the cross section of the ski.

Assume the ski at its thickest point is 1 cm thick, so assuming a rectangular cross section for simplicity's sake the distance from the centroid to the base would be .5 cm.

(1.85/(2(2)*pi))*(2.005(2)pi)=1.855m.

Each edge of the ski would experience an elongation of .5 cm, which is a strain of .5/185=.0027.

This would be well below the point of ultimate failure shown on the diagram shinbang posted.