I will ask to Ludovic Lacroix (his workshop is about 50 Km form my place) where he got the vibrachoc. I know it is rather expensive: about 10/20 euros per pair, if I remember well. He gave me few pieces, that I use as truck pad on the longboards.
Last winter I did few runs with one of this "vibrachoc" ski. Indeed they are less noisy that standard skis, that is the high frequency vibrations (over 1kHz) are stopped, but I am not sure it is true also for the low frequency vibrations (below 100Hz). I did not feel a striking improvement, but I did not do a serious testing.
Last week I read a technical study on the influence of kevlar on vibrations. It was done in 80's (2m long stiff narrow skis).
Indeed kevlar can dampen vibrations, but not always: it depends on how the ski is constructed (sandwich or torsion box) and on the amount of kevlar added to the ski.
It was not very clear, but the conclusion seems that the damping effect comes from the shear friction between the kevlar and the glass layers. It is clear that dissipation (friction) is needed for damping, as in car dampers
http://en.wikipedia.org/wiki/Shock_absorber
That is why I put diolen between the UD glass and the wood: I hope that the UD glass layer can slide respect with the wood core, and the friction will damp vibrations.
These days I am trying to put up a test system to measure vibrations in skis, using a pick-up coil and an oscilloscope. I will keep you informed.
By the way, there are still snowfields and glaciers in the Alps (few resorts are open year round), at least for the next few years, but during the hot summer I do not feel very much going skiing, I rather go swimming in the river, walking or biking.
But it is not excluded that, once the balsa skis will be finished (I will put diolen in there as well), I can think about testing them, maybe in September or October.
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