The answer to both questions is: Maybe. We spoke to an expert who knows more about a grinding and structures for double poling and long-distance races like the Vasaloppet or Birken than most.

Trond Fjerdingby from the Oslo Sportslager grinding workshop has nearly 25 years of experience in full-time ski grinding. He works with elite racers, top amateur skiers, and recreational skiers alike.

“The fluor ban in recent years has made grind and structure even more important for glide, as we can no longer rely on wax products to compensate.” Fjerdingby tells Langrenn.com.

This is especially true for double poling and long-distance skiing, where glide is the most crucial factor, and the wrong grind could cost you dearly.

Different Types of Ski Grinds

The primary purpose of grinding skis is to create a structure in the base that maximizes glide under specific conditions.

Oslo Sportslager and several other grinding workshops classify their structures with color codes: Red, white, blue, or green. Where red is for the warmest conditions and green for the coldest. Each color has different characteristics:

• Red grinds are coarser structures designed for warm, wet conditions from several degrees above freezing down to around zero. The main goal is to drain water away from the ski base and reduce suction.
• White grinds work in conditions around freezing and on most snow types in that temperature range. These are finer than red grinds but still focus on water drainage.
• Blue and green grinds are finer structures suited for below-freezing temperatures.
  • Blue grinds are effective from zero down to -10°C to -12°C.
  • Green grinds work best from -7°C to -8°C and colder. Their primary function is to create air pockets and friction between the ski base and snow to reduce drag in dry, cold conditions.

How Often Should You Grind Your Skis?

“It depends on how much you use them and in what conditions,” Fjerdingby explains. “But you should grind new skis and definitely get them ground at least once a year. If you look at the skis used by national teams, they rarely go through more than a few races before they are reground.”

Choosing the Right Grind for Vasaloppet and Birken

The ideal grind varies from year to year depending on weather and snow conditions leading up to race day. The time of day you start and how long you take to finish can also impact the best choice.

For example, conditions in Vasaloppet often change significantly from start to finish because the race starts early, temperatures rise throughout the day, and the snow near the start in Sälen differs from the snow near the finish in Mora.

“We test the entire Vasaloppet course every day in the week leading up to the race to find the best grind for that year’s conditions,” Fjerdingby says. “We then grind and prepare skis on the Friday before the race so they are ready for race day.”

The same applies to Birken, where conditions can be different from Vasaloppet due to its mountainous terrain.

Should You Re-Grind Skis Between Vasaloppet and Birken?

“Birken is usually colder than Vasaloppet, so a blue grind often works best. For Vasaloppet, it’s usually a choice between a white or blue grind,” Fjerdingby explains.

If you’re skiing both races, you can often use the same grind, especially if you fine-tune it with a manual rill. However, Fjerdingby emphasizes that if the conditions in Vasaloppet were harsh—exposing your skis to dirt and damage—you should consider regrinding before Birken to restore optimal glide.

Key Takeaways on Ski Grinding and Structure

• Ski grinding is a machine-applied pattern in the ski base, improving glide for different conditions.
• Manual structure (rill) is a temporary pattern applied by hand before a race.
• Warm, wet conditions require coarser grinds (red or white).
• Cold, dry conditions require finer grinds (blue or green).
• Vasaloppet and Birken may require different grinds, but blue and white grinds are flexible choices that work in a variety of conditions.

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