When stone grinding we are removing fine layers of base material from the surface of the ski base fractions of millimeters at a time. Grinding is done in 3 stages, first, we remove the old structure, imperfections, and sealed base material from the ski until we have a flat working surface all the way across the ski. Not all skis are created equally and in turn, some skis hold their shape over time significantly better than others. We are limited in grinding by the groove/grooves that run the length of the ski, once we run out of groove we are unable to grind the ski anymore. Some skis that are treated with care can be ground 20+ times, where others that are exposed to extreme heat can only be ground once or twice.
The second stage of grinding is when we prepare the ski for structure, arguably one of the most important steps, this is where we create a mirror finish on the ski and wipe out all existing structure. Without attention to detail on this step, grinds can have a huge variance from one ski to the next. By creating a polished finish, we are controlling all the variables we can before laying a final structure into your ski. This is a huge factor behind our grinding success especially when races come down to seconds. Any microstructures within the structure we have created provide liability in every condition.
Lastly is the laying of structure into your ski base, we have hundreds of hours of testing and refinement behind every one of our structures on our current grind menu. Structures are created by a small diamond bit (pictured below) cutting into a large grinding stone spinning at a given frequency. With our Tazzari RP23 machine we are able to control the speed on all moving parts (stone, diamond, drive wheel) and also control where and when the diamond is being pressed into the stone as it is revolving. This means the structure we can create are nearly endless, from elaborate sweeping lines to extremely fine and perfectly linear structures. The composition of the snow dictates which structure interacts best on each given day which leads many of our competitors to chase numerous grinds for every single snow condition.
With our product and technical knowledge we know not only how a structure will interact, but also know the importance of flex and ski selection combine with grind selection. Instead of trying to chase niche grinds that will only run under a full moon, we have paired our grind menu with our ski flex chart to cover your bases with a few options that make picking your race day ski setup easy and reliable.
*Above you can see the difference between factory structure vs high-quality Nordic structure machines like our Tazzari. There is a big difference in grind/speed quality. We recommend grinding all new race skis and getting old skis ground at least once per year.
Tazzari Albatross RP23 w/Vario Tech:
The machine that we use for stone grinding is a Tazzari RP23. This is a world cup quality machine that prepares cross-country skis with extreme precision and quality. The same model machine is used by numerous national teams around the world and has prepared skis for countless World Cup and Olympic medals.
Our specific model is a brand new 2020 production with the latest software updates and technology. Attached to the machine is an industrial chiller that keeps everything running at a specific operating temperature so that your skis are ground with the utmost precision every single time.
"Vario Tech" is the ability of the Tazzari to change the drive speed of the feed wheel as well as the downward pressure on the ski throughout the camber. With this ability, structures can be adjusted “on the fly” and at certain parts of the ski to maximize the performance of what the ski is doing in that given spot. At Pioneer Midwest, we have the ability to see where and how pressure changes over the length of a ski with our flex tester and ski analysis. The combination of our ability to see how and where your ski reacts to weight, and the ability to change the structure at that point is unique to our shop. With this combination, we are able to tailor each ski grind to a given customer and structure for you that isn't available anywhere else.
Testing these Vario structures, we have seen skis that are drastically freer underfoot and have improved top-end speed over non-vario structures. Vario not only allows you to flush out moisture and humidity under your foot where it's most necessary, but it also allows you to break up snow crystals and create humidity where you need it to help that ski release and break away from the snow in the initial contact zones.
Overall, it allows you to run grinds that you know are consistent and universal in warm traditionally tricky conditions and still get excellent results. Working with Lars truly solidified our mindset behind keeping a grind menu simple and using structures that you KNOW always run well. You are able to make universal structures run warmer by changing the moisture buildup under the ski without affecting the width of the structure which determines whether a grind trends towards newer or older snow.
Our technicians have extensive training on the use of this Tazzari machine and have prepared hundreds, likely thousands of skis. Please reach out via email if you have any questions about our procedures or stone grinding in general. ([email protected])