Pierre, I don`t remember what they were called, but a good friend of mine used to own complete board/wheels/trucks setup that looked almost exactly like that… maybe 18+ years ago? He and I evaluated it for a number of months. It was designed for one thing: a very low center of gravity, centralized parallel stance, with pure weighting and unweighting providing both drive and control. Great for traversing (fast) down the steepest grades we could find. Much more effective than any regular skateboard. As I recall, the components could have been made better, but it was still a valid idea, definitely more downhill ski-oriented than any other form of skateboarding, even the reverse-cambered slalom boards of that time period. Lots of serious fun.