Originally Posted by markojp
I don't know that durability is high up on the priority chain for race skis. For all mountain skis, think about how a side wall resists and disperses an edge hit from a rock as compared to a cap and you'll have the answer.
Nope, but Volant did fine durability wise. IMO what you're describing is a function of material, not shape. An ABS plastic cap won't have the tensile strength of a sandwich with some metal in it, for instance. But a metal cap, or one made of composites like they use for bindings and plates would do just fine in comparison, I'd guess. And if the composite included metal or carbon, would be lighter and stronger than wood/glass laminates, for sure. Also not sure I buy the rock hit idea; seems to me that a rounded shoulder is structurally sounder than a 90 degree angle. Won't the round arc tend to produce sliding strikes, and redistribute the force both directions nicely, while the square edge will minimize sliding, and redirect force mostly one way or another? Like Atomicman, I've seen some blown sandwich sidewalls that look like the entire force of the hit was concentrated in one area.
Originally Posted by quant2325
I always thought the idea behind a sandwiched ski vs. a cap ski was all about torsional stiffness, and the ability to control it along the length of a ski. Cap has to be easier to set-up (making manufacturing easier), but I was alway led to believe there is a loss of torsional stiffness.
Is about torsional stiffness, given that caps tend to be plastic. So the materials thing again. Do not believe, however, that caps are easier to set up. Again, there have been threads on this. Molds for caps are pricey, both to make and because each length requires a new mold. Whereas sandwiches are simple enough to do decently in a garage with a press made of plumbing hardware and wood (check out ON3P's photo thread on TGR about how they did it early on.) Once you've go the cap mold, may be cheaper per ski, in the sense of less manual labor, so assume that's how any caps at all can be made. As above, I have a hunch the loss of torsional stiffness is more a matter of the cap design and material than some inevitable aspect of caps. As said above, Atomic race skis are caps, and they seem to do OK in the stiffness department. Not clear if the caps are just cosmetic, have a feeling they involve some load. Sollie caps - fully load bearing - were moderately stiff as race skis go, not planks, but had a strong record, not hamburger.