The structure minimizes the friction between the base and snow and breaks suction in high moisture content snow.
Cold, crystalline snow calls for smoother structure to minimize friction points. Wet snow requires coarser structure to create channels for water to be repelled from the base.
When your skis performance deteriorates, it usually means one of two things has happened. You may find that your skis just need a simple side-edge sharpening. Or, potentially, the skis base material and base-edge need to be flattened, reset and restructured.
When you start your season, you may find that your skis perform perfectly… The skis roll-up to edge quickly, feel powerful and energetic. But, over time and use, the skis are subjected to powerful forces from making turns, the skis bend, flex and breakdown. Slowly, the base-bevel on a pair of skis increases, just from normal everyday use. Over time, this slow erosion of performance is hard to detect… Here are some signs that you need a stone-grind.
The skis base-bevel is difficult to see with the naked eye and requires the use of a true bar to read the slight bevel. If the skis are found to have excessive base-bevel, they will need to be stone-ground until the base material and base-edge material are completely flat.
When the base of a ski becomes warped, concave, convex or edge high, the stone-grinder resets the edge and flattens the base material. This flattening is performed by using a composite grinding wheel to true and flatten the base of the ski. The skis base surface is then sent over the stone, with varying speeds and passes, flattening the base and base-edge material.
Once the base and base-edge material are flattened, then the appropriate base structure can be applied for varying snow conditions a racer will encounter. The composite wheel is trued and dressed by a diamond bit that sets a pattern by traveling across the face of the stone.
Just as with selecting tires for car racing, a driver may use slicks on a dry track or a deep tread pattern for wet conditions… Selecting a specific pattern for a skis base material can maximize glide. Usually, wet/warm conditions require a structure with depth and width that helps move water underfoot, whereas cold dry conditions require a smooth structure that helps hold a thin layer of water under the ski.
There’s nothing like starting a new ski season on a pair of new skis. But if that’s not in the budget this year, don’t fret—there’s a hack for making your old skis run like new: the stone grind, a process in which skis are fed through a grinding machine to level the bases and balance the edges.
Even if you regularly do all the recommended ski maintenance—you wax the bases, sharpen the edges, and store your skis properly after each use—odds are your skis could use a professional reset at the start (or end) of the season. A stone grind does just that.
Over time, ski bases can become warped and lead to inconsistent performance. To check the flatness of a ski’s base, hold the ski on your shoulder with the base facing up and place a true bar (or level) across the base from edge to edge.
You’ve probably noticed that new and professionally tuned skis have structured bases, i.e. a visible pattern in the base material of the ski. The structure that you see on the base of the ski is like the tread on a tire, and directs water away from the base to optimize the ski’s acceleration and stability. If you can’t discern an obvious pattern in your skis’ bases, it’s time for a stone grind.
Beyond optimizing performance, sometimes ski bases can become damaged or contaminated by chemicals in the snow, skin glue, or fluorinated waxes. A stone grind can be a helpful and sometimes necessary tool to reset the condition of your base.
Crow's Feet in beautiful Bend Oregon, is your premier high end ski tuning shop with experience and expertise in base grinds, ski tunes, base repair, edge sharpening and base prep!