Originally Posted by
splat
Asymmetrical sidecuts occur because of the cooling/curing process involved with sintered uhmw pe plastic. It shouldn't happen, but the material develops a tension in it. When cut, this tension releases. In bases, it usually seems to want to release sideways, thus creating asym bases.
The reason those bases were asym is because the skis were protos and we hadn't made a mold yet. After cutting, they tweaked and created a larger radius on one side than the other. Typically, we wrestle asym bases into a mold and they come out to spec, having been properly realigned. For protos, we just press between a couple sheets of metal with no borders to hold the base to shape and the asymmetry of the base manifests in the skis. Once we feel like we have a viable design, we make a mold to ensure the skis have a symmetrical sidecut.
I have cussed and insulted the base manufacturers for this and even gotten refunds out of them for shipping us shitty material. Lately, in order to further minimize that tweaking when cutting, we have been putting the material through a heat up/cool down process. This has been very successful , as evidenced when the bases fall right into the mold like they're supposed to.
I have wrestled some ugly bases into molds and gotten perfect skis, but it's time consuming and frustrating. Some of the guys we had pressing last year were cheating when my back was turned and pressing the crooked bases between two sheets of metal and we shipped some asym skis. They got fired for that. If a company does not use molds for their skis, there's a good chance that either 1) their skis are asym or 2) they are getting some damn sweet base material that isn't twaeking and they aren't making asym skis. However, most people in the US are getting their bases from Crown Plastics, where we get ours.
To check for asym, all you have to do is hold your skis together so the edges are flush tip and tail, then squeeze and see if the edges match up in the center.