With over 30 years of waxing for xc ski racing, including a couple of Olympics and World championships, 100's of ski marathons and countless other races, I feel like I’ve learned a thing or two about prepping and waxing skis. In skimo racing, waxing isn’t a huge factor, but certainly time can be gained or lost on the more flatter “gliding” sections. I find that in my skimo races I almost always make up time on those around me in these sections. I don’t know if people just don’t bother to wax their skis before a race, or simply rely on the last tune they had, or perhaps are putting on the wrong stuff.... either way, improvements can usually be made.
My first thought on waxing for skimo racing is relief, because of how much easier it is than xc. You can’t use flouro’s as the slickness prevents skin glue from adequate bonding to the ski. So first off, it’s cheaper, and simpler because you don’t need a big array of waxes. I try to keep things simple. I have a wax that I like and know that it’s generally fast in most conditions. That wax is Rex Blue. It’s temperature range is -1 to -10 C. Even if you’re out of that range, it seems to work pretty good. It’s a very hard wax, so maybe not the easiest to apply, but that characteristic has many advantages. For one I think it’s more durable. Icy conditions don’t seem to wear it off as fast. I believe it also works well with the ski to skin interaction. A softer wax will actually be removed from the ski and incorporated into the skin glue, thus compromising it’s sticky effectiveness. Finally, as already noted and of utmost importance, Rex Blue seems to make skis pretty fast!
Another consideration that many skiers in all ski disciplines neglect is the structure in the base. This is actually a more important factor than wax in ski speed. As you glide over the snow the weight and friction actually melt the snow under the ski so you’re skiing on a thin film of H20. This can cause suction-and slow skis. Think about a few drops of water between 2 panes of glass. They’ll be stuck together like glue. Same thing with your skis, so you have to put a structure into the skis to break up this suction affect. Colder temps call for less structure (less thin film of melting water) and warmer conditions call for more structure (larger water film). I’ve noticed that many of the Euro made skis are manufactured with a pretty heavy structure. Maybe it’s because most are made in Central Europe, where it’s warmer and need a correspondingly larger structure pattern.
You can change this by stone grinding your skis. But do this with someone experienced in putting in a variety of grinds. Most local ski shops that just do alpine skis don’t play around with dressing the stone and experimenting with various grinds. I found this out the hard way just before one of the world skimo champs I went to. I had 2 pairs tuned by my local alpine ski shop and asked for a grind for warmer temps (for central Euro country). The stone grind they put in my skis made them about as fast as skiing on dirt. I was probably the first person to request a change in their stone grind pattern that required them to dress the stone. I ended up scraping this grind out with a utility knife blade which actually puts in a nice little structure itself for colder temps. There are also rilling bars and tools that you can put your own structure in or even the edge of a common metal file works pretty good too. I’ve got a cheap Toko rill tool that I use for my XC skis and the roller bars on it put in a nice linear structure that is pressed in and can be easily scraped out.
I guess the final dimension in prepping skis is sharpening the edges. Your alpine ski racers and tuners will have more insight that this old dog xc ski racer, but I’ll throw in my 2 cents. The best way to get a nice sharp edge is with a skilled stone grinder. There’s nothing better than a fresh grind with a razor sharp edge installed by a skilled technician. I’ve only found one tuner in my area that successfully did this and unfortunately the shop went out of business and sold their stone grinding machine. That said, it is possible to diy (do it yourself). I’ve tried using the tools alpine ski shops sell for the supposedly perfect angle, but I’ve never gotten them to work. So out comes the trusty file. I use quality ski vises to keep things in place for that nice sharp edge angle. Reliable racing supply (http://www.reliableracing.com/) has a dizzying array of tools for this purpose (files, guides, vises, stones, etc.).
My typical modus operandi for my skis is thus:
Pre-season: stone grind for a nice sharp edge (only time I’ll do this during the year, hoping the sharpness maintains for the season.
Race season: wax and structure as explained above
Post season: repair scratches with p-tex candle, apply a warm summer storage wax (to protect base-from oxidation and keep it from drying out). Put in a ski bag and place in a cool dry location
There you have it. Train hard this summer so you can fully enjoy your fast skis next year!!