This can also apply to skiers as well but I'm wondering if there is any numerical data on this? Like for e.g. if someone weighs 90kg, and let's say their board has 1300mm of effective edge being used. Is the cross sectional area of the edge in snow, say 5mm (?) So would the math be 90kg / (1300mm*5mm) = 90kg / (6500mm^2)? Or converting to pascals: 90kg is 882.59 Newtons, and 6500mm^2 is 0.0065 m^2, so 135,783 Pascals? Did I do my math correctly?
Anyways, I was bored and thinking about how many cycles of stress a snowboard can take before it reaches some form of plastic failure where the camber loses its pop. I would assume the wood is the weakest material out of all the stuff used (fiberglass, epoxy, etc)?
You forgot about the centripetal force due to turning. Ski racers in speed events (downhill & super-g) put up to 3.5 Gs of acceleration into the snow.
I also don’t think skilled snowboarders and skiers have their entire edge equally engaged in the snow, not at high edge angles. There’s an awesome shot of justaride Lars where a significant part of the middle of his board is off the snow so he’s actually riding just the tips and is bending the board to achieve turn shape. I have absolutely zero actual evidence to support this guess though.
But both of those factors, centripetal force and only riding the tips, would increase this edge pressure metric compared to your equation.
With regards to board life this has to be a factor of the type of wood used, if there are any transverse glue joints, what type of epoxy that’s used, maybe also how many times and how much the board is heated up during waxing, etc in combination with the amplitude and number of decamberings.
I don’t think edge pressure itself is relevant here necessarily, it’s more about the amount you decamber the board. Just thinking that you can generate more edge pressure on firmer snow for example. But I may be thinking about it wrong…
Dreaming about soft snow
Board life is an interesting topic... and I don't have the answer. I will say that my lighter Paulownia boards have broken-in & clapped-out quicker than even a (cheaper) Aspen core. Carbon will maintain some snap, but only in very specific directions. The disparity can start to feel odd.
And it's not just the wood type, but how it's used. My Stranda Shorty has Ash stringers in the core, and they've held up A LOT better than the ash topsheet on my Jones Freecarver (which is VERY smooth flexing now).
A relevant post pertaining to the forces in a turn:
Big White, BC, Canada
