Belt and Grind: How Tuning Machines Changed Skiing

Innovative tuning machines are the unsung heroes of skiing's improvement

Discovery S

Disciplined, consistent, on time, sober, the Discovery S is an anomaly in the ski shop. PHOTO: Christian Pondella

This story originally appeared in the September 2014 issue (43.1).

The Wintersteiger Discovery S in Footloose's back shop is a six-foot-tall green box enclosing an intricate dance of moving belts, stones, discs, servos, and hydraulics behind clear plexiglass windows. Skis are automatically plucked from a rotating conveyor shuttle, fed through the multi-stage tune process—belt grind, stone grind, edge bevel, sharpen, polish—then extracted onto another conveyor. The machine is controlled from a digital touchscreen that allows the operator to customize almost every variable of base structure and edge tune.

Right out of the wrapper, your skis work better than they did 10 years ago, and it's because $175,000 (and up) tuning robots are churning tirelessly in factories and ski shops.

Burly touring gear. Rocker. Airbag packs. Skiing has seen its fair share of innovations in the last decade, but the most pervasive improvement has slipped beneath the radar. Right out of the wrapper, your skis work better than they did 10 years ago, and it's because $175,000 (and up) tuning robots are churning tirelessly in factories and ski shops. That's mostly thanks to automated tuning systems pioneered by an Austrian company called Wintersteiger, and their Swiss competition, Montana.

Sure, the new skis are sweet, but if the base isn't flat and the edges aren't consistently beveled and polished, they're going to feel hooky, squirrelly—or both—no matter how much carbon there is in the layup, or how refined the rocker profile. Fifteen years ago, you never knew what you were going to get—at least half the new skis on the rack weren't even flat, and edges would frequently have obvious file or belt marks that could make them grabby. Now, according to Zach Yates, head tech at Footloose Sports in Mammoth, "…you can pretty much count on pulling off the plastic and being able to ski it. It's night and day from 15 years ago."

The dimensional difference between the best possible tune and a knee-tweaker is almost infinitesimal, but blind testing with racers has shown that even young kids can identify a base that is mere thousandths of an inch convex or concave within just a few turns on snow. While many techs can produce top-level tunes (in terms of precision) with a traditional manually operated stone grinder (a mere $40,000) and hand tools, it's a meticulous process rife with opportunities for mistakes, many of which will have unpleasant consequences on snow. A high-precision tune is totally possible with hand-filing, but doing it on a commercial basis—say, 30 pairs of skis a night over the Christmas holiday—requires machine-like discipline, attention, and consistency. And a lot of Band-Aids.

Hence the robots. Wintersteiger originally manufactured agricultural equipment, expanding into ski tuning in the '60s. The leading producer of modern base grinders since the 1980s, they introduced their first fully automated tuning machine in 2005, a massive modular system that can be configured to perform the entire tune process from base grind to wax and final polish, while made to take off the absolute minimum of edge and base material. There was some initial skepticism, but it didn't take long for the consensus to form among techs and skiers that the robot work was potentially as good as any hand-filed tune, and certainly better than the overall industry average. In short order, the new machine tunes became the benchmark.

Like the evocative smell of wax, there's a certain romance to the traditional tuning bench and tools, to the meticulous process that requires a sharp eye and a steady hand. There's a satisfaction in pulling a sweet stroke with a new chrome file and seeing a perfect spring-shaped spiral peel off the edge to reveal clean, sharp steel. But the romance tends to fade pretty quickly in the repair shop when you slice your thumb open, or realize how much fine particulate matter—steel, plastic, and fiberglass—you're inhaling and absorbing. Which is one reason even the staunchest old-school techs have embraced the fully enclosed machines that isolate them from a substantial chunk of the back-shop health hazards.

Ken Cramer, the senior vet at Footloose, has been pulling a file since the '70s. "I've always said that you have to file 500 pairs of skis before you start to know what you're doing," he says. "This machine can do that in one day."