XC SKI TECH: Stonegrinding For Today's Skiers, Part 1

While CyclovaXC is focused on XC Skiing, Cycling, and Running, this is the first of several articles to be posted on XC Ski tech. This article was written by Frank Lundeen and previously published in Master Skier Magazine:
Over the past few years, there has been more and more buzz about stonegrinding of Nordic skis. It is a fact that stonegrinding is the best and easiest way to produce a consistent, fast ski base to work with and ski on. Having skis with the proper stonegrind gives the skier a proper foundation to begin waxing your skis on. Just like a house is only as good as its foundation, a properly waxed ski is only as good as its grind. Stonegrinding does several things including increasing the speed of the skis, flattening the base of the ski (increasing stability), removing oxidation and old base material (improving the ability of the ski to take wax), removing nicks and scratches from the base of the ski, and giving you the optimum structure for any given snow condition. Considering these things, you will see that with stonegrinding, you will get maximum results from the time you spend waxing and maintaining your skis.

Not long ago, it was believed that the average racer would bring in their skis once every few years to be stoneground. After the stonegrind, it was then thought that there was a process that basically took the entire ski season to get the ski running at its highest potential speed. This may have been true in the past, but stonegrinding has evolved past this. Now, many top skiers have their race skis stoneground multiple times per season. This is possible due to improvements in ski bases, improvements in stonegrinding machines, additional procedures performed on ground skis, and lots of testing. I personally know of many top racers who have had their skis ground within a few days of major races (including last years Masters National Championships), have had the fastest skis there, and went on to win some of these races. This is a fact that some people can’t believe, but is definitely true. More and more tech shops are advertising race ready stonegrinds and this isn’t far from the truth.

There are just several things to keep in mind when choosing where to have your skis ground and which grinds to pick. When choosing a shop to have your Nordic skis ground at, I would recommend consulting someone who specializes in Nordic skis as there are very specific demands on X-C skis. It is also very important to find a shop that not only grinds skis, but a shop that normally goes through a finishing process with all skis being ground. Different shops have different ways of finishing skis, but it is very important that they have some definite way of cleaning excess material from the structure and removing hairs from the base. Many grinding machines have a finishing side of the machine for doing this specific task. The shop should also get some soft wax into the freshly ground skis.

When considering which type of structure to have ground into your skis realize that there are literally thousands of possible different grinds out there. Stonegrinding machines have special diamonds that “dress” the stone for different structures. Thankfully, most shops have several recommended grinds that they regularly do. And of these grinds, there should be a “univeral” grind which is what 80% of skiers choose. The grind, or grinds, that you choose should depend on how many different pair of skis you have to race on. One must also consider the type of snow that you normally ski on. If you rely on one or two pair to ski on, you would be best off with a “non-linear universal grind.” If you are one of those hard cores blessed with a quiver of skis, then it is time to do some thinking. If you live in an area with very diverse weather patterns like myself, you will need a variety of grinds. Serious racers commonly have four or five pair of skis with various grinds for different conditions.

  • Commonly after we get big snow falls, the temperature drops dramatically. Because of this, one should have a pair of good soft pack skis with a cold grind. We have had phenomenal success with this combo here in the Midwest.
  • A pair of soft pack to medium skis should be selected for a wet corn snow grind.
  • A medium to hard pack ski should be selected for a linear grind. The linear grind excels in corn snow, man-made snow, or fresh wet snow.
  • The most important grind to have in your quiver, the universal grind should be on a pair of soft pack skis and a pair of hard pack skis for normal (10’F to 30’F untransformed snow conditions).

With this array of grinds, one will be prepared for virtually any snow condition. Obviously, when you figure out the weather and snow conditions for your event, most of these different options will be ruled out. Just choose the skis with the appropriate structures and prepare and test those one or two pairs.

Now that your skis are ground, what are you to do? There are several things you can do to ensure that your skis will be rocket ships the first time on snow. Before you start working on your skis, refresh your memory on proper waxing technique as this is often more important than the wax you choose to use. Another thing to note is to make sure to have a very sharp plexi-scraper. Having a sharp plexi-scraper will ensure that you cut off any remaining hairs on your ski base and will work much better for scraping. I recommend following these guidelines to achieve optimum ski speed the first time out…

  1. Scrape and brush out the layer of wax the shop put on your skis after the grind.
  2. Using a copper brush (or other soft metal brush), brush the ski using long strokes from tip to tail. This will help stand any hairs on your base on end. The copper brush will not create miro-hairs.
  3. Now we will be performing the hot scrape. When hot scraping, use a soft wax. Apply it. While the wax is still warm, scrape off the wax using your plexi scraper. Make sure to use long, smooth strokes from tip to tail with the plexi-scraper. Begin brushing out the ski immediately with the copper brush, using long strokes from tip to tail. (You should only use the copper brush for brushing out wax when performing the hot scrape.) Finish brushing with the nylon brush and finally horsehair brush.
  4. It is very important to get several coats of a soft paraffin wax into the ski leaving each coat cool before scraping and brushing.
  5. After several coats of soft wax, it is best to get a variety of hard and soft waxes into the ski base. Fantastic results can be achieved by alternating hard to soft wax. By doing this, you will actually begin to harden the base of the ski producing a more durable base with the hard wax, yet get excellent wax penetration with the soft wax.
  6. Finally, move on to your wax of the day. You are well on your way to enjoying the fastest skis possible!

Remember, waxing can be as simple or as complicated as you want to make it. It is important to work with a wax system that you are comfortable with and simply match the snow conditions to your wax choice. Generally speaking, the more you wax your skis, the faster they will be. In many cases, just the stonegrind with a few coats of wax will dramatically increase the performance of your skis. Above all, don’t loose sight of the reason you love this sport, to enjoy skiing. Make sure to spend more time skiing than working on your skis and above all, THINK SNOW!!!

**Photo Credits to Zach Fink (stonegrinding pic) and Marty Wood (waxing pic).

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