Review: Outdoor Research Ferrosi Convertible Pants

Soft-Shell Hiking Pants
Outdoor Research Ferrosi Convertible Pants
$99, 11.5 oz. (men’s 30×30)
Sizes: men’s 28-42, women’s 0-18

I lived in the Outdoor Research Ferrosi Convertible Pants on three multi-day hikes that put them through quite possibly the widest range of three-season weather most backcountry wanderers might ever see: trekking hut-to-hut for a week on Iceland’s Laugavegur and Fimmvörðuháls trails and several dayhikes around the country, where cold wind and periods of light rain accompanied us almost every day; on a nine-day, nearly 130-mile hike through the High Sierra in August, mostly on the John Muir Trail, in temps ranging from the 40s to high 60s Fahrenheit, strong wind at times, and one hour-long rainstorm; and on a five-day, 43-mile backpacking trip in the Wind River Range in the week before Labor Day, where we had dry, sunny days ranging from the 40s to the 60s F with moderate wind some days.

And over those two dozen or so days, these pants were the only bottom layer I needed about 98 percent of the time.

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I’ve also worn them on numerous other outings, including an 18-mile, 7,300-foot, 13-hour, four-summit, partly off-trail dayhike with my 23-year-old son in Utah’s Wasatch Range in early October, with warm alpine sun, cool wind at times, and temps from the 40s to the 60s Fahrenheit.

Why choose these convertible soft-shell pants instead of some combination of hiking shorts and pants? For a very compact and lightweight system that delivers hard-to-beat versatility in a huge range of weather conditions.

The key component here is OR’s tough yet comfortable Ferrosi fabric, which shakes off light precipitation, blocks some wind, and dries quickly from body heat. Most importantly, these pants breathe supremely well, so I remained at a good body temp wearing these pants and a rain jacket while hiking for hours in intermittently windy, wet weather and moderate temperatures in Iceland, when waterproof-breathable rain pants (which aren’t nearly as breathable as soft-shell fabric) would have caused me to overheat. I only pulled rain pants over them in colder temps and wind or steady rain.

I also wore them (and a rain jacket) through more than an hour of windblown, steady rain in an August thunderstorm in the High Sierra without getting chilled; and they dried out fast after the rain stopped. Similarly, on a dayhike of the 13-mile, 3,500-foot Burgess Pass Loop in Yoho National Park in the Canadian Rockies, on an overcast, cool day in the 50s with some rain showers, the pants got soaked from wet brush overhanging the Burgess Pass Trail, then dried out from my body heat within about 20 minutes once we got above treeline.

That breathability also kept me comfortable from cool mornings to warm afternoons in the Wind River Range and throughout a nearly 10-mile, 4,700-foot dayhike up Mount Adams in New Hampshire’s northern Presidential Range on a sunny October day that started out with temps in the mid-30s and finished with the thermometer around 60 F, with cool wind at times. And only the waistband got a little damp with sweat all day.

Plus, the pants are light and cool enough to wear in moderate temps on dry days and you can zip the legs off reasonably quickly when things heat up. They lack side/ankle zippers to enable pulling them over shoes or boots; but those add weight, bulk, and zippers that could fail (especially in a high-abuse area like lower legs). Personally, I’d rather just remove shoes to pull pant legs on and off.

The fabric also has a UPF 50+ rating for sun protection and is made from 46 percent recycled material.

The legs zip off to create shorts with a nine-inch inseam—good coverage even in a light, warm mist while still creating plenty of ventilation and cooling. Like any soft-shell fabric, the Ferrosi eventually soaks through in steady rain; bring waterproof-breathable rain pants if you expect sustained rain and cool temps (as I did in Iceland).

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At just over 11 ounces, they’re about as light as you’ll find in weather-resistant, convertible pants with the durability for hiking, and they squish down to slightly smaller than a liter bottle. Then again, you’ll never actually stick the pants into your pack—only the legs, which compress to about a half-liter in volume, tiny enough that I’d stuff them into an exterior pack pocket.

The fit is trim but neither tight, which isn’t pleasant for hiking, nor baggy, which can result in the lower pant legs picking up excessive moisture from rain or slapping against wet vegetation. The trim pant legs facilitate faster drying and the adjustable cuffs cover boot tops but also fit neatly under low gaiters. Whenever the sun came out and warmed things up in Iceland or the White Mountains—knowing the warmth might not last long—I easily rolled the pant legs up to my knees and walked rather than take the legs off and on repeatedly.

The basic feature set is all you need in hiking pants: two spacious hand pockets that lack zippers but are deep enough that nothing slips out; one zippered thigh pocket big enough for a smartphone or a pair of lightweight gloves; two back pockets, one of them with a zip; an inserted, metal shank button closure, more durable than a sewn button; and a soft, brushed tricot-lined waistband with belt loops—and an internal drawstring, so your pants won’t slip south, but also remain comfortable under a pack hipbelt.

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Testing the Outdoor Research Ferrosi Convertible Pants on Iceland’s Laugavegur and Fimmvörðuháls trails.
Testing the Outdoor Research Ferrosi Convertible Pants on Iceland’s Laugavegur and Fimmvörðuháls trails.

The Verdict

For a wide range of weather conditions, from hot sun to occasional rain and cool temps, you’ll find very few pants (and shorts) with more versatility for dayhiking, backpacking, climbing, and other three-season adventures than the Outdoor Research Ferrosi Convertible Pants—especially at this price.


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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 The Big Outside’s Gear Reviews page for categorized menus of all gear reviews and expert buying tips.

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2 thoughts on “Review: Outdoor Research Ferrosi Convertible Pants”

  1. i have used Ferrosi convertible pants since the originals came out at least seven years ago. In fact, I still have my original pair that have traveled around the globe, including K2 basecamp, Everest advanced based camp, the Grand Canyon, the Rockies in both Canada and the U.S.A. and so many more places, in conditions and temperatures even more diverse.

    The fabric and design, mainly of the pockets, has changed. I have one pair of the newer design and fabric which is lighter and more breathable. Whether the new fabric will be as durable only time will tell. The original pair now are living out their days as a farm pant where continue to perform and carry on with an equally demanding life.

    My only observation is that they seem to have grown longer and a bit more baggy. Either that or I am shrinking with the passing of time. A great product from OR! By the way I have a couple of their original Ferrosi wind shirts, which sadly are no longer available, which are equally stellar.

    Convertible pants are a great option for people who go on multi-day, or week or month trips because of their versatility. I have some other brands but none have replaced my OR Ferrosi convertible pants.