Quantifying skis, and repairing the Trak Bushwacker
Counting ounces is an easy place to loose perspective, and comparing ski weights are a great example of this. All the common areas of ambiguity loom especially large here, namely that claimed dimensions are often wrong, and that relevant performance rubrics like flex cannot be quantified. For a recent article I wrote for BackpackingLight (on Tools for Human-Powered Oversnow Travel), I wanted to be able to compare ski weights with a decent degree of accuracy. Skis weights are very important, both because you’re adding that weight to the ends of your legs where it’ll do the most damage, and because even the lightest ski rigs are very heavy.
I realized quickly that what I wanted was a single number which would represent surface area per unit of weight. Calculating surface areas of complex shapes is daunting even for someone with a greater grasp of math than my own, and a bit of research turned up no better option than this convenient online tool. So I use that to give me a figure in square centimeters, divide that by the weight in ounces, drop the units, round to the nearest whole number, and I have a crude but consistent tool for comparing skis across genres and shapes.
You’ll have to read the article to get the whole scoop, but I found an intriguing congruence across all the skis I compared. The highest tech, carbon skis had the same ratios, and the skis several tiers down (the lightest, all-wood skis) also had the same or similar numbers. My presumption is that this tells the tale of what currently available technology can do.
For example, take the skis pictured above. Top to bottom we have the Bushwacker (150, 85/80/83, 40 oz each), Altai Hok (145, 121/109/121, 46 oz each), and the Karhu Guide (185, 109/78/98, 44 oz each). Their approximate surfaces are, respectively; 1256, 1645, and 1582 square centimeters. Dividing surface are by weight (per pair, to get smaller numbers), we get whole numbers of 16, 18, and 18. The best skis in the article got a 24. It’s not perfect, but it is one more way to look at things.
On to the Bushwackers, another recent ski swap acquisition. They were in rough shape, with delaminating tails and lots of chips off the edges, and wouldn’t have been worth the 25 dollars I paid for them were not such a unique ski. They’re wide, almost straight, with a fairly stiff camber and a half, plastic fishscale base (not extruded, actual plastic), and no metal edges at all. I’m not sure what role they will play, but to get them up and running I worked Gorilla Glue into the tails and clamped while they set over night. With the excess trimmed off, the tails and many places on the tips and edges got coats of Shoe-Goo for waterproofing.
Now all I need is some snow.