Tecnica Plasma S
$150, 1 lb. 14 oz. (US men’s 9)
Sizes: men’s 7-14.5, women’s 5.5-10.5
The notion of a hiking shoe that can be heat-molded to your feet like the liners of ski boots seemed too good to pass up. So I took the Tecnica Plasma S shoes on what struck me as two perfect tests: dayhiking 12,662-foot Borah Peak, highest in Idaho, which entails an almost relentlessly steep, 5,200 vertical feet of ascent and descent in seven miles round-trip, mostly on trail, but also includes a few hundred feet of third-class scrambling; plus backpacking the Teton Crest Trail. The Plasma S delivered on the promise of a customized fit—but it’s important to understand the limits of this technology. Read on.
I also wore these shoes on several dayhikes of up to nine miles along the Middle Fork of the Salmon River during a six-day rafting and kayaking trip in mid-July, where I had more moderate hiking and hotter temps than on Borah.
The non-waterproof Plasma S (there’s also a Gore-Tex version, see below) uses the same technology as the brand’s Forge GTX boots. The shoe’s removable footbed—which by design is noticeably more supportive than the flimsy footbeds that come with many low-cut hiking shoes—and part of its upper can be custom heat-molded to your feet using a special machine, similar to heat-molding a ski boot liner, although the two processes differ significantly.
I got the shoes heat-molded at a local retailer that carries the Plasma S, a free service provided to anyone buying the shoes and which takes 20 to 30 minutes. The two-step molding process basically shapes the heel, insole, and to some extent the arch area to those parts of your foot. It affects only the area of the shoe demarcated by the orange spotted pattern on the upper, so it isn’t identical to heat-molding a ski boot liner, which wraps completely around and conforms to your entire foot.
I’m told by employees who do the custom molding that it gives satisfactory results for most purchasers of the shoes—but it will not correct a fit that was poor prior to the molding. In my case, these medium-volume shoes fit pretty well before the custom molding, but afterward, the fit was as good as I’ve ever found in low-cut hiking shoes—a performance aspect particularly noticeable on the steep descent of more than 5,000 vertical feet in 3.5 miles off Borah, when my feet might have taken a beating in shoes with a less-than-perfect fit. In the Plasma S, my feet never slipped or developed any hot or sore spots; and after I removed the shoes at my car, my feet genuinely felt like I’d done a much shorter hike.
The shoe’s locking laces and overlap tongue design helped secure the fit and allowed virtually no small stones or dirt inside the shoes.
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A dual-density EVA midsole with a small TPU shank at the arch provide good stability and protection underfoot, even when carrying up to about 35 pounds on the Teton Crest Trail. Weighing a couple of ounces shy of two pounds for a pair (US men’s 9), the Plasma S deliver solid support and torsional rigidity for a shoe that light; there are competitors that are lighter still, and some are as well armored against trail abuse as the Plasma S, but their fit varies and isn’t customizable as with these shoes. Although primarily for dayhiking, these shoes have adequate support for lightweight or ultralight backpacking.
The uppers are made of a synthetic polyamide fabric with TPU laminated reinforcements to guard them against bashing against rocks and other abuse. Combined with a mesh lining, the shoes proved reasonably breathable—my feet got a little sweaty on hot and dry July hikes along the Middle Fork of the Salmon, but remained comfortably dry even under the hot afternoon sun while descending the lower stretch of the Borah Peak Trail. (A side note: Offering shoes that are non-waterproof, and designed for good breathability, in black doesn’t make a whole lot of sense; but color is driven by consumer demand, of course.)
The Vibram Plasma Megagrip outsole design is aggressive for a shoe in this category, with relatively deep and widely space lugs (compared to other low-cut hiking shoes, not with backpacking boots) that bit securely into Borah’s steep, sandy trail and loose, small scree. A patch of smoother outsole under the toes gave me confident purchase when smearing and scrambling the exposed, third-class sections of Borah’s infamous Chickenout Ridge. But oddly, the lugs at the forward edge of the outsole’s in-cut heel—which provide the braking power going downhill—are so pronounced that a few times I caught them on a rock or even on my lower pant leg and nearly tripped.
There’s also a waterproof-breathable version which can be heat-molded, the Plasma S GTX ($180).
The unique heat-molding available with the Tecnica Plasma S noticeably improves the fit of this low-cut shoe, which also provides good support and grip for dayhiking and lightweight or ultralight backpacking.
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NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See my Gear Reviews page at The Big Outside for categorized menus of all of my reviews and my expert buying tips.