Hey Guys,
my neighobr and i are going to make a stab at building skis and boards this summer. but because we live in the mighty minnesota. the main conditions we encounter are hardpack. from your expierences what core materials have worked best for hardpack?
Perfered Core Material for hardpack
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Not everyone is going to see this one the same, but it should be interesting to compare all of the varying points of view. Here's mine.
When you ski hard pack, the ski edge gets a lot less penetration into the snow surface resulting in less edge hold and greater torsional stresses on the ski. Hard snow also provides more feedback from the snow surface in the form of vibration. I think a softer wood core exhibits much greater damping qualities than does a harder wood. I use pine, and I really don't notice vibration issues. I also use inserts for reliable binding retention. To increase torsional stiffness and edge hold, you might consider an extra layer (or two) of +45/-45 bi-axial cloth. I also like a bit more camber, a little less side-cut, and a slightly stiffer overall flex for a ski that I'll be using for high-angled hard snow.
G-man
When you ski hard pack, the ski edge gets a lot less penetration into the snow surface resulting in less edge hold and greater torsional stresses on the ski. Hard snow also provides more feedback from the snow surface in the form of vibration. I think a softer wood core exhibits much greater damping qualities than does a harder wood. I use pine, and I really don't notice vibration issues. I also use inserts for reliable binding retention. To increase torsional stiffness and edge hold, you might consider an extra layer (or two) of +45/-45 bi-axial cloth. I also like a bit more camber, a little less side-cut, and a slightly stiffer overall flex for a ski that I'll be using for high-angled hard snow.
G-man
werts wrote:
So, from my perspective, the core has two main functions... to separate the composite layers and to provide for damping. If you want it light and damp, maybe you should try using a softwood. Use the wood core to dampen your ride, use the composites (and their spatial relationship to each other) to get the other physical properties you want.
Oh, another thing that I forgot to mention earlier regarding skis that'll be seeing a lot of ice/hard conditions... I'd suggest not getting too carried away with the width. A wide ski on ice can flog your legs in real short order.
G-man
Yes, it is. The bare core flexes like a limp noodle. But, just about any other wood is also going to be pretty flexible when it is machined down to just a few millimeters thick. A ski doesn't get it's stiffness from its core material... a ski becomes stiff related to how far apart from one another the core positions the top and bottom layers of composite. I made a pair of skis with a pine core that has a waist thickness of 13mm and tip and tail thickness of 3mm. It's one of the stiffest skis I've ever skied... almost too stiff. Because the core is pine, the ski is still quite light... light but stiff... can't beat that. Personally, I'm tending to be moving away from longitudinally really stiff skis in favor of a more moderately stiff ski , but with lots of torsional rigidity... less glass in the 0 degree axis, more in the +45/-45.but isn't pine very flexible over the whole length of the wood?
So, from my perspective, the core has two main functions... to separate the composite layers and to provide for damping. If you want it light and damp, maybe you should try using a softwood. Use the wood core to dampen your ride, use the composites (and their spatial relationship to each other) to get the other physical properties you want.
Oh, another thing that I forgot to mention earlier regarding skis that'll be seeing a lot of ice/hard conditions... I'd suggest not getting too carried away with the width. A wide ski on ice can flog your legs in real short order.
G-man