Posted on 4th Sep 2011 @ 9:45 PM
Here is a collection of precious inside information on how to maximize your speed using ski waxing, ski tuning and ski technique!
Deep in the Volkl Race Room
Buried deep beneath the sprawling corporate headquarters of Volkl USA in scenic New Hampshire lies a small, orderly, well-lit tuning workshop...the likes of which any righteous home tuner would probably offer to trade their home for! Here, working under the supervision of tuning wizard (and now Volkl USA Product Development Manager) Mike deSantis, is where world cup technician Thomas Parks and race room manager Dave Glotzer prep and tune the skis of some of the world's fastest racers. We had the good fortune of spending an afternoon in this subterranean tuning shangri-la with Mike, Tom and Dave as they demonstrated how to prep a pair of world cup race skis. Here's a glimpse of what we saw...
Race skis fresh from the factory...
Volkl world cup race skis are constructed only slightly differently from race skis you find at your local shop. The materials and construction lay-ups used for these skis are virtually identical to those found in your ski shop racks, but the skis are entirely laid-up by hand from start to finish, with particular attention being paid to what racing discipline the ski is to be used for. Volkl world cup skis, however, are all made the same for all their racers...meaning there are no special make-ups for particular individuals. The fastest Volkl race skis used on world cup courses are saved from one season to the next (until worn out or retired), with only their topsheets upgraded whenever Volkl changes their graphics.
Unlike some of their competitors, Volkl USA gets their race skis from their factory in Europe with only a rough base grind on them...preferring to impart their own finish stonegrind on bases here in the states. Mike and his staff have tested many different structure patterns over the years, and have developed a few special stonegrind patterns (which are kept confidential, of course) that work best for their U.S.-based racers. Following this final stonegrind, the ski base is belt-sanded using a specially 'broken-in' 80- grit sandpaper to flatten the tops of any sharp structure ridges.
These world cup race skis are only stonegrind once a season...unless a particular pair receives enough base damage during the season to warrant a regrind. They believe that, once stoneground, bases should only be waxed frequently and the structure simply 'refreshed' occasionally using a special steel brush (which we offer in our catalog). The base structure gets worn smoother during the season due to snow abrasion (removing p-tex micro-hairs and leaving a more polished surface), while the bases get more and more saturated with frequent waxing...this creates the fastest bases. They feel it usually takes half a season for a new race ski base to become 'broken-in' to this extent.
Hand tuning tricks...
After stonegrinding skis, the special hand-tuning work begins. First, they round off any sharp edges along the ski topskin using a body (pansar) file...provided the ski has vertical sidewalls (which quite a few world cup race skis still do). On cap skis, these top edges are already usually rounded. They also round off steel edges in front of and behind contact points on new ski tips and tails with a 8" mill file (although they don't 'detune' past this point on current sidecut race skis), as well as the aluminum tail protectors.
Then they remove a considerable amount of the plastic sidewall material that sits directly above the side edge using a sidewall planer with a carbide cutting blade. This keeps plastic from clogging up file teeth when imparting and maintaining a 3 degree (or greater) side edge bevel throughout most of the long race season. Then a body (pansar) file is used to plane away material from the entire side of the ski above the edge along nearly the entire ski length...this not only ensures a smooth clean sidewall to reduce drag when edging, but also creates more "reveal" of the side edge to accommodate greater side edge beveling throughout the season. Lastly, they use the carbide blade on a SKS Racing Combi tool to "backcut" part of the side edge and sidewall material (see diagram) to further keep plastic sidewall material out of the way when filing.
Side edge beveling...
Mike, Tom and Dave use a 3-degree file bevel guide in conjunction with a body file to initially set the side edge bevel, followed by a medium grit (blue DMT) diamond stone to smooth and deburr the side and base edge surfaces. This process is then repeated using an 8" mill file, followed by a fine grit (red DMT) diamond stone to polish the side and base edge surfaces. Final polishing of the edge surface is done using a single thickness of 320-grit sandpaper cut to fit atop a DMT diamond stone. This is again used with a 3-degree file bevel guide to maintain a precise bevel angle during the final honing of the edge.
Volkl recommends a 3 degree side edge bevel for their sidecut race skis, and 2 degrees for recreational skis.
Base edge beveling...
The Volkl guys prefer to set base bevel on edges only once a year, although they deburr and polish these edges regularly throughout the season. They recommend 1.5-degree base bevel for sidecut race skis, and a 1-degree bevel for classic race shapes.
Although Tom Parks uses two wraps of masking tape around one end of an 8" mill file to set a 1 degree base bevel, he doesn't recommend it except for only the most experienced tuners...especially with the deep sidecuts on many skis these days. Instead, he advises using a base edge bevel guide (Beast tool or similar) to ensure accurate base bevel results.
When base filing, Tom makes three passes down the ski with his 8"mill file. The first pass is made using 3 or 4 overlapping file strokes with fairly light pressure. The second pass is made with heavier pressure, but again making 3 or 4 overlapping strokes. On his third (and usually final) pass, Tom takes one long stroke down the entire length of the base. After filing one base edge this way, he flips the ski around in his vise to bevel the other edge, but this time working from tail-to-tip so as not to change his body position or filing movements. To polish base edges after filing, he again uses a fine grit (red DMT) diamond stone in conjunction with the base edge bevel guide to maintain precise bevel angles.
Some waxing guidelines...
Mike and Tom use several pre-mixed wax formulas they've created using Swix or Toko wax for most races. They believe in keeping waxing and tuning as simple and uncomplicated as possible so they can exactly reproduce winning results time and again. They brush fluoro wax out of bases with a steel brush after every race, do most of their world cup brushing by hand (vs. using a rotobrush), and only do dry brushing (vs. hydro- brushing with water). They like to use the Swix blue polish brush after horsehair brushing for the best final polishing results. They also give a word of warning...be aware that a wax iron will heat the tips and tails of skis more than the center section due to thinner construction at these points and more metal present there (relative to core material)...so be careful and don't overheat tips and tails!
At the race start...acclimatizing-
After prepping and waxing skis for a race, they lay or bury skis base down in the snow at the race start so they'll cool to match the actual snow temperature. This cooling squeezes more wax out of p-tex bases, which consequently should be removed. They brush the base 5-6 times to remove any excess wax from the structure using a horsehair and blue nylon polish brush, and don't hesitate to work the brush in both directions along the base.
Analysis of a fast racer...
We asked the Volkl guys how important they felt good race prep was for winning world cup races. They felt that in speed events (Super G & Downhill), good tuning and wax account for 50% of a racer's speed, while the racer's ability accounts for the other half. In technical events (Slalom & GS) the racer's ability accounted for more (around 80%), while good tuning/waxing became less important (20% or so).
Miscellaneous tips from the Volkl techmeisters...
Using 100% fluoros...they prefer Swix Cera F when the course is flatter at the bottom, and Toko WetJet when course is flatter on top. They also say it's okay to apply Cera F or WetJet more than 2 hours before a race...contrary to other wax company's claims.
Use base tape when beveling base edges to protect a structure that you don't want to get scratched.
Wrap a sheet of fiberlene around a foam cork to create more heat and guarantee greater cleanliness when rubbing in high or pure fluoro waxes (including Swix Cera F, Toko WetJet or Dominator Q powder).
A simple way to measure base edge bevel is with a straightedge or true bar laid across a ski at or near the waist where the ski is 60mm wide. Hold the bar so it's sitting flush atop the steel base edge on one side...this should cause the other end to lift up slightly on the other side of the ski. This raised height (in millimeters) equates to the degree of base bevel you have. See the diagram for details...
Parting words from the Volkl pros...
Think of ski tuning like working with fine wood...it involves a finer touch (like planing and finishing) than heavy-handed work.
PAM WARMAN'S TIP...
U.S. Ski Team TechnicianPam Warman is a former ski tuning technician for the U.S. Ski Team. She’s also the first woman ski technician ever to reach the ranks of World Cup service. Pam started out working in ski shops in South Lake Tahoe...which she still calls home, although she is often on the road with the U. S. Team both here and abroad. Here’s a few tips we picked up from Pam while working with some speed team members recently at Mammoth Mountain, CA.
“Before using any edge bevel guides or tools, be sure that whatever part of the tool sits against the ski or snowboard base is clean. These surfaces often pick up wax, filings or other grunge...and this accumulation can either scratch your base structure or affect the precision of your bevel results. To remedy this, rub the dirty surface of the tool with a piece of fine scotchbrite or fibertex to quickly and efficiently remove any buildup.”
“After filing or touching up steel edges, always deburr and polish the edge for smoothest, sharpest, most efficient results. When working on slalom race skis or boards, final polish the side edges last...this will lend just a little extra sharpness for better edgehold when cranking lots of quick tight turns. When working on GS or speed skis, polish the base edge last instead, since the extra vertical sharpness you want for slalom can actually create a little more drag...which can reduce speed in faster events.”
“After hot-waxing bases, apply a coat of low-fluoro paste wax to ski or board sidewalls and tops to help improve glide when cranking ‘em up on edge in carving turns, as well as help prevent snow buildup on the topsheets.”
“To clean bases on skis or boards before waxing, wrap a piece of 220 grit silicone carbide sandpaper around a true bar or file, and make numerous passes with this ‘sanding bar’ down the length of the base from tip to tail. This will clean away any grunge or leftover wax, as well as help expose the base structure.”
“To get the longest life from a file when using it with a bevel guide, start by using only the very end of the file...just enough to contact the steel edge and ensure it won’t slip off. As the teeth at this part of the file get dull, however, extend the file out a little further so fresh teeth are again exposed. When the first several inches at the very end of the file are dull (on both sides of the file, of course), snap off that section of the file in a steel bench vise, etc. You’ll now have a shorter file, but one with fresh sharp teeth exposed. Continue using it until the file gets too short to work well with your bevel guide. This trick lets you maximize the use you’ll get out of any mill file, plus save you money.”
When Californian Jeff Hamilton set a speed skiing record of 150 mph in Vars, France, he went faster than a skydiver falling from a plane, and about 65mph faster than the highest speeds reached by downhill racers.
Here's some background on what happened...a light layer of fresh snow fell over the firm course the night before, and was groomed before competition with a winch-drawn snowcat. Jeff used 240cm Dynamic speed skis with graphite bases that he and his dad, Dick, had hand-tuned.
They had previously glide-tested 5 pair of speed skis with different structures at Boreal Ridge near Lake Tahoe before going to France. Surprisingly, in wet corn snow conditions there, they got the fastest results on skis with a fine linear structure..versus a coarse structure that conventional wisdom would dictate. Also the skis weren't stoneground...instead they were hand-sanded using 150-grit silicon carbide paper. Jeff's dad structured the bases by sanding from tail-to-tip (versus tip-to-tail), postulating that any loose p-tex hairs would lay flat pointed toward the tail of the ski for less friction. He followed this with a scotchbrite pad and brushing.
In France, they hot waxed with a fluoro-carbon glide wax, and then buffed it in vigorously by hand with a natural cork until it took on a glazed appearance. The excess wax was removed with a plastic scraper and then brushed. Lastly, a dry layer of Toko WetJet was applied using a horsehair brush, in hopes of getting fast acceleration right out of the start. It must have worked...Jeff went from 0 to 124mph in only 6 seconds!
At top speed, Jeff crouches low with his feet apart, riding the inside edges of both skis for maximum stability. To prep for this, he side files edges until they're a mere 1/32" wide to reduce drag, then rounds off the lip so the edge is dull but highly polished along the entire length of the ski. At high speeds, a sharp edge could otherwise dig in and hurl him off course.
Also interesting...Jeff and his dad glide-tested their speed skis the same way nordic skiers do...at low speeds. Although alpine technicians have long argued that low and high-speed glide testing involve different forces, friction, heat, etc....and therefore aren't the same...it seems, from Jeff's results anyway, that there may not be that much difference after all.
The first speed skiing contest, called the Kilometre Lance (Flying Kilometer) was held 65 years ago in St. Moritz, Switzerland...the winning speed was a whopping 66mph. Where will it end? Some speculate speeds will eventually peak between 160 and 175mph.