No matter what skiers say about all the swell aspects of their sport, they have for years suffered from two great pains: 1) aching, numbed feet and 2) cold feet. Oldtime leather boots have long since given way to plastic (hasn't everything?), but plastic shells have only increased convenience, not comfort. Now, after years of experimenting, an answer may be at hand—or foot. The age of the foam ski boot has arrived.

This is not calculated to be startling news. The first stirrings in the foam-boot world began as far back as nine years ago and last year the boots were sold widely. But this season, for the first time, every major manufacturer is on the line with a foam model, ranging from $120 to $175. The colorful boots marching across the opposite page and above are a typical selection. All are "foamies."

The foam is on the inside. One simply slips on the boots and the bubbly is poured or injected under pressure to snugly conform to every gnarl, corn, peak and hollow of the individual foot. The foam then sets up and, presumably, retains its shape forever. If done correctly—and most manufacturers are quick to confess that foaming is still an imperfect art—the light new boots give firm support, plenty of warmth and a strong sense of control. The latter sensation is so unusual that Mel Dalebout, one of the bootmakers, insists that his boot provides "power steering."

Ski-boot people call this new process "customizing," a term that has an exclusive, expensive sound to it, but among skiers the term foamies has already become well fixed and probably will never change. While foamies covers the subject well, the materials used are technically all elastomers—which is anything resembling rubber. Specifically, most of the boots use polyurethanes or silicones. Beyond that basic, the secret lies in mixing the foam compound with a catalyst to produce just the proper blend of air bubbles and solid matter. Each manufacturer claims to have that mixture exclusively, but Seattle's Peter Kennedy, who pioneered the foam principle years ago, figures the foam mixtures are like cheeses: "There are hundreds of them, all good."

For something this new and reasonably complicated, the foamies are catching on fast. In the East, Harry Vallin of Scandinavian Ski Shops says, "We are stocking only foam boots from now on; we are selling fit, which is essential to happy skiing." Sun Valley's Pete Lane has gone all out for foaming, which he claims is the boot of the future even though "everyone is still learning about it." In Vail, Colo. the Gorsuch shop has moved to 50% foamies, and Salt Lake City's Stevens-Brown has sold more than 200 pairs this season. Estimates indicate that foam boots have about 10% of the market this season and are coming on stronger.

So accountants are pleased, but what do the foam-footed skiers say? First reports are enthusiastic, particularly from those with hard-to-fit feet. And the foamies actually may fit too well. One SI tester reported: "My foot is not exactly the same size every day; that happens to everybody. Also, I don't wear the same sock-pants combination every day and there is a difference where the ski-pants seams fit on my foot."

Still, the market is growing. The customized boots are clearly coming on and, as one skier puts it, "Look, I don't care what they pour inside there—just so it keeps my feet warm."

PHOTOERIC SCHWEIKARDTCOLORFUL PLASTIC outside, foam inside—and lighter than the oldtime leather models—these boots represent the design revolution. From top to bottom, left, Rieker Orbis $135, Peter Kennedy $140, Nordica Astral Pro $140; top right, Le Trappeur Pro $135, A&T St. Moritz $135, Lange Competition $175. The vivid new skis arrayed in the background, also advanced designs, are the Hart Cutlass, Olin Mark 1, K-2 Competition and V√∂lkl Explosion. PHOTOERIC SCHWEIKARDTFOAM IS PRE-MIXED, then injected with a businesslike foam gun into the toe of Lange's new competition model boot. The process is painless. PHOTOERIC SCHWEIKARDTSHOOTING UP of Daleboots is done in pairs through the heels. The outer shells arc magnesium, adding a bold-spaceman touch.