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THE TALL STORY IN SKIING THESE DAYS IS A BOOT THAT EXTENDS TO THE KNEE
Anita Verschoth
December 22, 1980
Just when we thought that our fiber-glass skis and foam-injected boots would be good for 10 years before going out of style, the equipment makers have done it again. After years of claims that shorter skis are easier and better for the recreational skier, long skis are in vogue again. Manufacturers declare that what everyone wants now is "high performance."
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December 22, 1980

The Tall Story In Skiing These Days Is A Boot That Extends To The Knee

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Just when we thought that our fiber-glass skis and foam-injected boots would be good for 10 years before going out of style, the equipment makers have done it again. After years of claims that shorter skis are easier and better for the recreational skier, long skis are in vogue again. Manufacturers declare that what everyone wants now is "high performance."

Well, maybe, but a skier can't have high performance if he has a hard time turning. So, to go with the longer skis, bootmakers have come up with a blockbuster: knee-highs that aren't exclusively for experts and racers. They're for the novice and intermediate skier as well, and they're a blessing, because with the increased leverage they provide, less muscle is needed to make turns. The early models—by Dolomite, Nordica and Tecnica—range in price from $235 to $295 and are already in the shops. But the serious skier would be wise to wait for the boots that will let him drive his skis with the precise handling of a sports car—the Kastinger- Porsche Design boot, which will sell for around $390 the pair.

The sleek, charcoal-colored Porsche has a futuristic look, as though it were custom-made for Darth Vader. But what you don't see is even more impressive. Under the hood, so to speak, is a finely tuned machine that far outperforms the other knee-highs. The boot, built by Kastinger and Co., an Austrian manufacturer that has been making ski boots since 1909, was designed by an unassuming American engineer named Daniel Post, who tinkered with the first crude models in the basement of his Averill Park, N.Y. home.

Post, 51, now a professor in the Engineering Science and Mechanics Department at Virginia Tech, is an inventor who has worked in diverse fields. He holds six patents—two for his revolutionary boot. Post is not a crack skier. He and his wife, Frieda, say they are timid on the slopes. But their three children are something else—pro skiers all—and they indirectly planted the idea for a new boot design in their father's head.

Irwin, 27, was a certified ski instructor before he became an engineer, and his sisters, Ellen and Marion, 25-year-old twins, traveled the professional freestyle circuit for five years. Ellen teaches skiing at Winter Park, Colo. and is one of only two women on the Professional Ski Instructors of America demonstration team. Marion, attending Colorado State, had a career that included three overall world freestyle titles and five world ballet championships.

"The children were obsessed with skiing," says Post. "It dominated their conversation day and night. We discussed the mechanics of the sport, frequently with emphasis on the contribution of the boot. Then, eight years ago, I heard a presentation by Billy Kidd in which he talked about the motion of the legs for turning. That crystallized my thinking that a skier could transfer motion to the skis more efficiently with a different style boot."

By the spring of 1972, father and son were trying out the first prototypes, made of old laced-up boots and steel uppers. "We used materials that were easy to construct," says Post, "because geometry, not the material, is the key here."

The early version of Post's boot illustrates the mechanics behind the design. There's a stiff structural member that rises up from the heel around to a precise point on the shin just below the knee. The structure, or lever, gives the boot lateral stiffness. The feature that makes Post's design better than that of other knee-highs is that at the shin of his boots this structure attaches to a stiff plastic yoke that connects to a soft flexible cuff hugging the strongest part of the calf. When the leg moves, so does the yoke, transmitting the motion of the front of the leg to the bottom part of the boot and the ski.

"With a conventional ski boot, the side of the leg pushes against the sidewall of the boot, causing it to 'angulate' and edge the ski," says Post. "With our concept, the boot angulates through the action of the front of the leg. As the skier flexes his legs to angulate the skis, his lower legs also rotate through a vertical axis. This is an automatic and natural motion dictated by human anatomy that occurs unconsciously with angulation."

As a result of this rotation, the front of the leg moves farther sideways than does the side of the leg. Boots actuated by the front of the leg therefore yield a greater angulation than the conventional boot. Post calls this "amplification of edging," and in practice, it means that with a smaller body motion, a skier wearing the new boot can achieve the same angulation of the ski as a low-boot skier. The advantages include quicker maneuvers and less fatigue. The novice finds his first snowplows are a cinch, and the advanced skier can carve parallel turns with more precision and ease.

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