DEC 93 Winter bags for mere mortals who get chilly when the mercury drops below 0 degrees F by Dave Getchell Let's say right up front that you're not a serious winter camper who swells with glee when the weatherperson announces temperatures preceded by a minus sign. Nor do you live for armpit-deep drifts and air so cold it'll freeze a thought. What you do enjoy, though, is the solitude of off-season (nonsummer, in other words) camping. You handle it just fine when temperatures hover in that nippy range from zero to freezing: spring and fall trips to the high country, summers on the glaciers, and general winter use in most places. You're a 0 degrees F mummy person. A "medium mummy" offers several advantages over the -20 degrees F extreme winter bags Backpacker tested in 1991 ("Maximum Mummies," October). A bag rated down to 0 degrees F fits into a typical internal-frame pack, whereas many big mummies won't. It also can save two pounds on your back, and can contribute as much as $200 to your trip fund. Plus, a -20 degrees F bag is just too warm above about +20 degrees F, but a 0 degrees F bag is far more versatile because it extends into warmer use. To find out just how versatile, we rounded up mummy-shaped bags in six different constructions stuffed with five different fills. We sent them to seven American Alpine Institute (AAI) mountain guides and Backpacker field editors, who racked up more than 300 nights sleeping on the job last winter, spring, and early summer. They snoozed (or tried to) in stuffy huts, wind-rattled tents, cramped bivy sacks, dank snow holes, and swaying "porta-ledges" high on rock walls. Some testers enjoyed the dry cold of Aconcagua in Argentina (22,834 feet), the Rockies, and the Nevada desert, while others endured the damp chill of Patagonia, the North Cascades, and coastal New England. We rated the bags on packability, loft, roominess, temp-rating accuracy, weatherproofing, ventilation, field drying time, and construction quality. Testers awarded each bag an all-things-considered (overall) score based on gut feel. (See accompanying ratings chart for specific details.) To better understand the field findings, let's backtrack briefly to explain how sleeping bags work. First of all, crawling into the sack doesn't actually add warmth. A sleeping bag only slows how fast you lose heat through conduction, convection, and radiation. Conductive heat loss isn't usually a major factor except underneath you, which is why a good ground pad is so important. Convective heat loss results from air circulating outside the bag, otherwise known as cold wind. This chilling effect occurs as you toss and turn and pump warm air out. The shell fabric, hood, neck collar, and zipper draft tube all limit convective leakage; the less air-permeable these features are, the warmer you'll be. Controlling radiant-heat loss involves what one industry treatise terms "limiting radiative thermal transfer through low-density fibrous assemblies." Translation: You sleep warmer when swaddled in fluffy insulation. Up to a point, the smaller the diameter of the individual fibers, the more radiant heat is retained by a given amount of insulation. But what about bag shape? Size? Fill? Do you want good old goose down or new-wave synthetic? Shell materials? What details make a good bag good, or a bad one bad? Shape: For the 0 degrees F temperature range, consider only a mummy bag. Trying to sleep at 3 degrees F in any other type of bag without a snug hood and draft collar will (rightly) make you wish you'd stuck to summer camping. Size: Bags aren't sized as precisely as shoes, though a few brands come close by offering bags in 6-inch increments. Most are simply available in regular (fits to about 5 feet 9 inches) or large (fits to perhaps 6 feet 3 inches). You should be able to lie out flat with the hood cinched and not have your feet scrunch up at the end. Lie down on the outfitter's floor to confirm the fit, and forget the salesperson's glares. Go up a size if you want to wear extra clothes or sleep with water bottles and boot liners to keep them from freezing. Fill: Insulation used to be an easy choice, but recent innovations have blurred the distinctions between down and synthetic. Today's top of the line down bags are more weather-resistant than past models, while a whole passel of new-generation synthetics have grown lighter and more packable. Down---Choose "goose fur" if you value light weight and packability above all. For a given bag weight, you'll sleep warmer in down if you keep it dry, because down soaks up water like a sponge. The only thing worse than a cold night in a soaked down bag is a cold night in nothing at all. Down fill "breathes" better than synthetics, thanks to a higher vapor-transmission rate, so it's less stuffy at higher temperatures. Given reasonable care, down often retains its loft for 10 years or more. Down's quality is expressed by "fill power," which is the number of cubic inches one ounce of down will fill after a 24-hour lofting period. The industry standard for decent down is 550-fill; 650- or 700-fill is the fluffiest variety commercially available. The other downside of this fill is cost; a bagful of 650-fill down wrapped in a Gore-Tex shell might cost three times more than a no-frills synthetic sleeper. On the other hand, basic down bags cost less than some hi-tech synthetics. Synthetics---Choose synthetic fill if you insist on going where the weather's hopelessly wet and you don't want to worry about keeping your bag bone-dry. This doesn't mean you should leave it out in the sleet, however. A dry bag is preferable to a wet one no matter what it's stuffed with. Most synthetics air-dry three or four times faster than does down. A 0degree synfill bag will likely weigh about a pound more and take up 20 percent more space than a comparably warm down bag, but both figures represent significant improvements over older synthetics. While the new fills use a variety of novel engineering approaches, all the different types fall into two basic categories. There's the short-staple fills, like Lite Loft, Primaloft and Micro-Loft, that are comprised of shorter, finer fibers. And there are the continuous-filament fills, like Polarguard HV, which employ coarser but springy filaments that are hollowed out to save weight. In our testing experience, the short-staple fills generally pack smaller and are slightly warmer for a given weight, while continuous-filament fill isn't quite as efficient but retains its loft longer. Depending on how hard you use it and how often you launder it, figure on two to four years' use from a typical synfill bag before the loft starts to fade. SHELL MATERIALS The shell forms your bag's first line of defense against wind, dew, rain, and spilled hot chocolate. The shell fabric must also handle a sort of catch-22 duty: It must perform all of the above, yet still allow your personal perspiration to escape so it doesn't soak the bag from the inside. Different shell fabric types juggle these demands with different degrees of success; chief choices are Gore-Tex, polyester microfibers, and nylon. Gore-Tex: The raingear world's favorite breathable barrier protects all of this group's most weather-resistant bags. Notice we said "weather-resistant" and not "waterproof." That's because the thousands of stitch holes in baffled or quilted bags can't be seam-sealed. On the other hand, Gore-Tex fabric isn't air-permeable, so it adds enough convective protection (windproofing) to extend a bag's comfort zone about 10 degrees lower. The material is admittedly expensive, and in colder conditions enough condensation can collect inside the shell to leave the down soggy. Still, a Gore-Tex shell can keep a down bag puffy despite a heavy dew or your partner tracking wet snow into the tent. But if you want a Gore-Tex bag you'd better act fast, since the stuff will no longer be available in sleeping bags after spring 1994. Gore's new Dryloft shell material is expressly designed for sleeping bags and baffled or quilted parkas. Dryloft uses a thin PTFE laminate (polytetrafluoroethylene, or Teflon), which the company says is twice as breathable as Gore-Tex but retains comparable weather resistance. Our brief field tests of prototype Dryloft down bags were encouraging. Dryloft's polyester outer fabric feels noticeably less crinkly and seems slightly more water-repellent than the now-prevalent Gore-Tex/nylon ripstops. We comparison-tested a Dryloft down bag and a taffeta-shelled synthetic bag by leaving them in a flyless screen tent during an all-night rain. The Dryloft bag came out damp but still fairly puffy; the other bag was drooling water. Both bags sun-dried in an hour or two, though the Dryloft bag started out not nearly as wet. The Gore-Tex/Dryloft situation is like the relentless march of new computers; the current product works great, but there's a promising newcomer in the pipeline. If you need a bag and want Gore-Tex, don't wait---the subtle difference isn't worth freezing for. Microfibers: These fabrics are tightly woven of ultrafine filaments, usually polyester. A microfiber shell offers better water and wind resistance than plain nylon without the cost of Gore-Tex. They feel soft and cushy, and air-dry quickly. Even so, a micro-fi- ber-shelled bag requires meticulous care to stay dry in lousy weather. Nylons: Basic bags use shells of nylon taffeta or ripstop. Taffeta is a simple flat-weave fabric; ripstop uses little squares of larger threads to reinforce its weave. Neither is any more water-resistant than a paper bag without some sort of waterproof coating or laminate. On the plus side, both bags are light, reasonably wind-resistant, breathable, and inexpensive, and both have been used on perfectly good sleeping bags for ages. The test results emphasize that detailing is what separates the best from the runners-up. When bag shopping, look critically at features like the zipper draft tube, neck collar, and hood; all should seal snugly and be easy to operate. Beware of sewn-through seams that will leak heat. Zippers without antisnag tape sewn alongside will inevitably jam just when you're ready for a midnight pit stop. Some bags save weight and bulk with a thinner bottom panel, which puts a premium on a good ground pad underneath. Here are the bags we tested. CARIBOU Gore-Tex/Primaloft 0 degrees: This limited-production sleeper combines the most weatherproof shell (Gore-Tex) and the most water-resistant insulation (Primaloft). We'd call it the wet-weather bag for off-season paddlers, alpine climbers, Pacific Northwest bushwhackers, and other assorted "out-there" characters. Our Rockies editor Mark Jenkins bivvied in the Caribou high on a rock wall while dangling on a porta-ledge. In December. In a snowstorm. "I froze my butt off," he recalled, "but I didn't freeze off anything more important like fingers or toes, so that speaks pretty well of the bag." AAI's equipment manager Steve Glenn called the Caribou one of the best synthetic bags he has used. Its downlike packability led AAI guide Joe DeMarsh to dub it the "smallest-stuffing synthetic that really is warm to its rated temperature." Not all concurred on the temp rating, though, giving the Caribou a barely average score in that department. Though it field-dried fastest of the group, the Gore-Tex/Primaloft outweighed all but one and felt uncomfortably stuffy at warmer temperatures. Still, if you're determined to travel where the weather will be wet, cold, and miserable, you'll sleep warmer and dryer in the Caribou than in any other bag we've found. EMS Mountain Micro 0 degrees: Here's a well-made basic down bag with nice design touches such as puffy dual draft flaps, a zippered knickknack pocket, and a compressor stuffsack with a fleece lining that helps it double as a pillow. "The EMS is light, compressible, and warm," wrote Glenn, "but the owner needs to be an absolute fanatic about keeping it dry. The microfiber shell relies heavily on its DWR (durable water-repellent treatment) for weather resistance. We recommend relying on a good tent or bivy sack as well. AAI's Mark Houston thought the EMS bag was roomy without excessive space to warm up. "It seems to fall around midrange of the industry average for 0 degrees F rated bags," he reported. "That is, it's really more of a 10 degrees F or 15 degrees F bag." He said he'd rate it higher if not for the oversized baffling that left the bag underfilled here and there. Bottom line: The EMS is a good bet for the budget-conscious backpacker bound for cooler, not-too-wet climates. FEATHERED FRIENDS Tern GTX -5 degrees: This is a go-anywhere, do-anything bag, conservatively rated and quite weather-resistant. I spent several nights in the Tern on open bivouacs at about 15 degrees F and wasn't even cold in the first light of dawn when I'm always cold. It's remarkable how so puffy a thing could disappear into so small a stuffsack. The Tern is one of the warmest bags tested, yet also one of the lightest. Who can argue with that? Guide S.P. Parker took the Tern to Patagonia, where he rarely zipped the bag up when it was above freezing. After a month of dodging horizontal rain, Parker raised the sole sour note: "Gore-Tex protects the down, but the bag still loses it when it gets wet." At least the black liner fabric speeds solar drying time. Not even our most determined nitpickers could find much to quibble about regarding the Tern's construction. A full storm flap covers the main zip, a Gore-Tex-lined hood keeps heavy breathers from soaking the down, and snaps close the draft collar without grabbing beards or pile jackets the way Velcro tapes do. KELTY Soft Touch Lite Loft +5 degrees: The Kelty came across as a well-executed synthetic sleeper with a low price and high stuffability that's gained it a midpack finish. This Lite Loft mummy saw more wet weather than most during two trips to rainy Patagonia. "It doesn't hold much water, so it can be wrung out and air-dried fast," noted Parker. AAI's Mark Bowling thought the Kelty packed quite well for a synthetic bag, helped out by its standard four-strap compressor stuffsack. Tester feedback differed about the bag's detailing. Parker liked the roomy footbox and shoulder area but was less-than-thrilled with the skimpy draft collar. The main zip's anti-snag-tape treatment drew praise from Bowling and barbs from Parker. The nylon taffeta shell makes no pretense beyond the most rudimentary weather protection, though it is nicely stitched. Guides' consensus: The Kelty is best for wet-weather trips in good tents. L.L. BEAN Down Mummy 0 degrees: The Bean entry didn't exactly wow the testers, but it impressed them as a utilitarian down sleeper with a synthetic-bag price. Houston thought that the baffle spacing and overall fill control rivaled that of more expensive down bags. Houston's wife, Kathy Cosley of AAI, felt the Bean bag had plenty of loft, but she wouldn't have minded more fill around the hood. Design glitches chipped away at its overall score. "Why is the zipper taped on just one side?" Parker asked. "Does only one side of the zipper suck in fabric?" Houston found that the tape stiffener tended to push the draft tube away from the zipper, causing a full-length cold spot. Every tester commented that they'd like to see a drawstring on the otherwise puffy neck collar. We'd characterize the Bean bag as a good choice for those who prefer the compactness and light weight of down but can't afford to fork over $450 for the privilege. MARMOT Kestrel GTX 0 degrees: When we asked guides Cosley and Houston to test 0 degrees F bag while climbing Argentina's 22,834-foot Aconcagua, both fretted that the bags might not be warm enough. After some cajoling, Cosley agreed to take the Kestrel because she felt confident that any Marmot bag would be conservatively temperature-rated. The Kestrel was also one of the lightest bags in the group and the most packable, which dispelled any of their lingering doubts. After the climb she said, "We spent many nights on Aconcagua at or below the bags' rated temperatures, and stayed warm with a bit of extra clothing worn inside. The Marmot is really versatile for its size, maybe a little hot for summer, but toasty enough for winter in nonextreme climates." Houston agreed: "By whatever relation to reality the manufacturer's temp ratings are, the Kestrel qualifies as warm." Both noted, however, that some design details seem dated, like the neck-collar drawstring that tended to open the collar's Velcro closures. The company says the glitch has been fixed on the new models. MOONSTONE Maxima -5 degrees: Though not as packable as the top down bags, the Maxima is equivalent in warmth---quite unlike some synthetics we tried. Moonstone uses three layers of Lite Loft on top and two on the bottom to save weight, but you'd better have a good ground pad. Glenn thought the plain taffeta shell absorbed quite a bit of moisture, although "the dark colors solar-dried fast, even under anemic North Cascades sun." Joe DeMarsh gave the Maxima a maximum warmth rating, and thought its loft was relatively unaffected by moisture, which he admitted was spilled soup. Though the hood and zipper worked well, Glenn was not enamored with the horseshoe neck collar: "Every time I rolled over, a major gap developed at the neck." He reported that AAI's rental Maximas are standing up reasonably well to regular washing and fluff-drying. DeMarsh's summation of the Moonstone ran short and sweet: "A most excellent bag." REI Nod Pod 0 degrees: The Nod Pod is a basic Lite Loft mummy that is light, fast-drying, roomy, and inexpensive, but it just didn't stand out in this group. But more to the point, it stood out for the wrong reasons. The thin bottom cuts weight and bulk, but it continues up over the foot section, leaving scant insulation around a part of your body that's already hard to keep warm. The draft tube didn't like to cover its zipper, and the horseshoe neck collar couldn't be adjusted for a snug seal. Testers agreed that the Nod Pod was acceptably warm to about 15 degrees F, but any colder than that and they'd be pulling on pile jackets and down booties. SIERRA DESIGNS NorthernLite 0 degrees: The NorthernLite went a long way toward derailing Cosley's long-held belief in the superiority of down bags. "Puffs up very nicely for its compressibility," she said, "and for its loft, it's the least bulky synthetic bag I've seen." The soft polyester-taffeta shell helped it stuff smaller, and the fabric's lustrous sheen often made the Sierra Designs the first one picked out of a pile of bags. The boxy cut won kudos from wide-bodied testers. Houston gave the NorthernLite strong weatherproofing scores because "it lacks the spongelike qualities of down." Most testers awarded better-than-average warmth ratings, though Houston demurred: "On the night I slept outside in a very humid 25 degrees F, I must confess I wasn't very warm." The Sierra Designs bag almost drip-dried in the field even though it has a light-colored shell and liner. The NorthernLite makes a strong, moderately priced candidate if your traveling to a place where you're likely to get wet. Yet it isn't so bulky you'd rule it out for colder, drier climates. SLUMBERJACK Discovery -5 degrees: The Discovery proved big-guy roomy, fast-drying, and impressively stuffable---smaller, even, than some down bags. Trouble is, the diminutive size of the packed bag comes at the expense of a warm night's sleep. No other bag out of the lot collected such dismal warmth and weatherproofing scores. Sample comments: "I was cold at 20 degrees F, and I'm not a cold sleeper." "Chilly near freezing, even in a tent." "Loft . . . what loft? This is one cold motha." "The hood kept heat in well, which is good because the collar did very little." "The zipper let in so much air that I could almost feel the wind blowing outside." THE NORTH FACE Moondance HV 0 degrees: The Moondance combines a microfiber shell, Polarguard HV insulation, and a fuzzy-warm Coolmax liner. The shell shed water well until the initial water-repellent treatment wore off. The new hollow Polarguard HV insulation remains warm when wet and stuffs better than the original version, but the Moondance still was the group's biggest lump in the pack. It was also noted that the bag's temperature rating seemed warmer than average. Reaction to the fuzzoid liner depended on what clothing testers wore. "It adds appreciable (and appreciated) warmth in not-so-cold conditions where you aren't wearing lots of clothes," said Glenn. But others found it a mixed blessing when wearing fleece to bed because the furry surface grabbed the fleece and twisted the whole liner. Testers lauded the ample, well-insulated hood and footbox, but they had little praise for the snaggy zipper and nonexistent neck collar. WESTERN MOUNTAINEERING Antelope Super GTX 0 degrees: The Antelope was the other bag we had to convince Houston to take up Aconcagua. Ironically, it turned out to be his favorite. "It renews my faith in humanity to see something so well-made," he gushed. Nighttime lows ranged from 40 degrees F at lower elevations to -5 degrees F at high camp, and he stayed warm with the judicious addition of a down jacket at the 19,300-foot-high camp. Not bad for the test's lightest bag. Like any down bag, this one is hopeless if soaked, but the dark, airy lining speeds sun-drying of minor dampness. The Antelope's collar and double draft tubes are the best we've seen; the tubes are amply filled and attached to an extra-wide base with no sewn-through seams. The hood wraps around your head, hats and all, while maintaining full loft. The only construction fault was an indifferently stitched stuffsack with seams that split at the drawstring. RATING THE MEDIUM MUMMIES THIS IS A SUMMARY OF INFORMATION. FOR COMPLETE DETAILS SEE THE DECEMBER 1993 ISSUE. Overall Impression - 1=poor, miserable, toss it, 2=fair, so-so, ok, but..., 3=good, solid, average, decent, 4=very good, beats most, I want one, 5=Excellent, superior gear, I need one. CARIBOU Gore-Tex-Primaloft 0 degrees: $389. Overall 4. Hi Points: exceptionally weatherproof, compact. Lo Points: stuffy at warmer temps., marginal temp. rating EMS Mountain Micro 0 degrees: $259. Overall 3.5. Hi Points: warm, light, compact. Lo Points: limited weather-resistance, a bit heavy FEATHERED FRIENDS Tern GTX -5 degrees: $451. Overall 4.5. Hi Points: impeccable construction, high warmth-to-weight ratio. Lo Points: not much KELTY Soft Touch +5 degrees: $185. Overall 3.5. Hi Points: low price, well-made. Lo Points: skinny neck collar, snag-prone zipper L.L. BEAN Down Mummy 0 degrees: $215. Overall 3. Hi Points: light, compact, rock-bottom price. Lo Points: limited weather-resistance, drafty draft tube MARMOT Kestrel GTX 0 degrees: $455. Overall 4. Hi Points: warm, compact, well-made, great hood. Lo Points: gaps in neck collar MOONSTONE Maxima -5 degrees: $260. Overall 4. Hi Points: lofty, warm, dries fast. Lo Points: ineffective neck collar, a bit bulky REI Nod Pod 0 degrees: $185. Overall 2.5. Hi Points: low-cost, compressible, light, roomy. Lo Points: poorly insulated foot area, ineffective neck collar SIERRA DESIGNS NorthernLite 0 degrees: $190. Overall 3.5. Hi Points: low cost, compact, luxurious fabric. Lo Points: gaps in hood and collar when closed SLUMBERJACK Discovery -5 degrees: $179. Overall 2. Hi Points: roomy, stuffs small, inexpensive. Lo Points: cold at rated temp., ineffective draft tube and collar THE NORTH FACE Moondance HV 0 degrees: $265. Overall 3.5. Hi Points: warm when wet, toasty liner, ample hood. Lo Points: bulky, no neck collar, snaggy zipper WESTERN MOUNTAINEERING Antelope Super GTX 0 degrees: $445. Overall 4.5. Hi Points: extra-warm, compact, highly weather-resistant. Lo Points: poorly made stuffsack Here are some questions we asked the testers to consider for their ratings: Compressibility: Does stuffed bag take up more/less space than the others? Do you need a magician (or gorilla) to cram it into the stuffsack provided? Loft: How well does bag puff back up after unstuffing it? Roominess: Is there roll-around room, or does sleeping in this mummy make you feel like one? Temperature rating: Is manufacturer's rating optimistic (cold, low score), reasonable (OK, average score), or conservative (warm, high score)? Weatherproofing: How well does outer shell handle wind, wet ground, condensation, or leaky tent? Any cold spots around hood, zip, or draft tube? Ventilation: How well could you cool off on warmer nights? Does insulation breathe well? Does liner feel warm, or clammy? Field drying time: After a damp night (snow cave, bivouac, leaky tent), how quickly does bag dry out in the sun? Construction quality: How well is bag put together? Includes nice design touches, sloppy stitching, stubborn zippers, sewn-though spots, and so on. Overall impression: All things considered, how would you rate this bag against the rest of the group? Note: This score reflects a gut reaction and not necessarily the other scores awarded. RESOURCES Caribou Mountaineering, 46 Loren Ave., Chico, CA 95928; (800) 824-4153. Eastern Mountain Sports, One Vose Farm Rd., Peterborough, NH 03458; (603) 924-6154. Feathered Friends, 2013 Fourth Ave., Seattle, WA 98121; (206) 443-9549. Kelty Pack, 1224 Fern Ridge Parkway, Creve Coeur, MO 63141; (800) 423-2320. L.L. Bean, Casco St., Freeport, ME 04033; (800) 341-4341. Marmot Mountain International, 2321 Circadian Way, Santa Rosa, CA 95407; (707) 544-4590. Moonstone Mountaineering, 5350 Ericson Way, Arcata, CA 95521; (800) 822-2985. REI, P.O. Box 88125, Seattle, WA 98138-2125; (800) 426-4840. . Sierra Designs, 2039 Fourth St., Berkeley, CA 94710; (510) 843-0923. Slumberjack, P.O. Box 7048A, St. Louis, MO 63177; (314) 576-8000.. The North Face, 999 Harrison St., Berkeley, CA 94710; (510) 527-9700. Western Mountaineering, 130 Lewis Rd., #2, San Jose, CA 95111; (408) 629-9907.