Hands-on Gear Review
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Street Price: $345
Pros: Highest warmth-to-weight ratio of any bag tested, custom options include zipper, fill, and draft tube, and hydrophobic down, waterproof dry bag stuff sack.
Cons: Not as versatile as a quilt (doesn't adapt to clothing/body type), zipper can come undone.
Best Uses: Ultralight three-season use.
The ZPacks 20 Degree bag offers the absolute highest warmth-to-weight ratio of any sleeping bag we've ever tested. However, ordering it is not very convenient, since it is not available from major retailers, and only directly from the small manufacturer in Florida (custom-made, involving long delays in delivery). But, if you can get past the idea of ordering a custom-made bag, you won't be disappointed. Our top bag available from retailers and top ultralight option with a hood is the Western Mountaineering Highlite.
ZPacks takes what most retailers would call a "superlight" bag and chops the unnecessary bits. Off goes the hood, the draft tube, and on goes a small and light zipper. The bag weighs a mere 17.1 ounces on our scale, performs admirably below freezing, and includes the best stuff sack we've ever seen included with a sleeping bag. ZPacks sleeping bags push the fast and light performance envelope to the next level.
The only significant drawback to this bag is its fixed girth. Quilts have the advantage of being able to adjust to the amount of clothing you're wearing or to various body types. The ZPacks 20 Degree bag performs at the highest level in three-season conditions but doesn't provide the versatility of a quilt; all but the skinniest people it won't be able to accommodate a down jacket in the winter.
The Katabatic Gear Palisade is our highest rated backpacking sleeping bag and our top choice for one lightweight bag that can be used in both summer and winter temperatures. If you prefer a hood, consider the Feathered Friends Peregrine but be prepared to carry an additional seven ounces and pay the extra cost of a more complex bag. Those on a budget can't beat the $100 Kelty Cosmic Down 20.
Also see our General Purpose Sleeping Bag Review and Winter Sleeping Bag Review.
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OutdoorGearLab Editors' Hands-on Review
After testing over 40 three-season sleeping bags we believe ZPacks line of sleeping bags – available in 10, 20, 30, and 40-degree models – offers the greatest warmth-to-weight ratio for three-season applications. The company's 20 Degree bag is our top choice for fast and light missions where we won't wear a midweight or heavier jacket inside the bag.
Features and Fit
This bag is about as simple as it gets. There's no hood no draft tube (to insulate the zipper) and it's cut trim to fit athletic people. The bag is available in two widths and three sizes, which allows you to get the best fit for your body type and specific end use. The bag has a small toe box that's comfortable for backpacking; unlike expedition winter bags, this does not have room for extra clothes and abundant electronics.
ZPacks offers a handful of custom options for this bag. The standard zipper length is 3/4 and is designed for you to sleep on top of the zipper in cold conditions (thereby eliminating the need for a draft tube). If you aren't comfortable keeping the zipper underneath, you can add a draft tube (0.8oz) for $20. Ultralight webbing straps, much like those found on quilts we've tested, can replace a zipper. Or you can drop the zipper entirely and sew the bag up, similar to the Feathered Friends Vireo, a winter climbing bag.
We took the ZPacks 20 Degree bag head-to-head with our top-rated hooded bags from the world's best down companies. This bag is significantly warmer for its weight than any other three-season hooded bag we've tested. It's designed for long distance backpacking, which remains it's best application, but our trimmer testers were able to squeeze a midweight down jacket inside, which expands the bag's application to fast and light alpine climbing. With light layering the bag kept our testers warm into the low teens.
It's Missing a Hood?!
Yes, and this a good thing. Hood-less sleeping bags have three significant advantages over their hooded counterparts: (1) They're more comfortable. Only a handful of the 70 sleeping bags we've tested have hoods that are truly comfortable when fully cinched. Separating the hood from the bag allows you to turn over without getting lost inside the hood and without spewing moisture vapor into the bag (which adds weight and reduces loft). Our testers unanimously agree that hood-less bags are more comfortable than bags with hoods. (2) Hood-less bags are lighter! Most people do the majority of their backpacking in above freezing conditions when hoods are rarely needed. Why carry it if you don't need it? (3) Hood-less bags cost less to manufacture. As described below, we rarely carry a dedicated down hood. Why pay the additional cost of a hood if you don't need one?
Our testers, who generally hike with a hooded baselayer, lightweight hooded fleece, or hooded jacket, rarely – perhaps on one trip out of ten – bring a dedicated down hood. We believe hoods are best if you're using the bag at or below its temperature limit and find a hat/jacket hood/balaclava to be heavier or less warm than a down hood. We've tested down hoods from four different companies, including the Katabatic Gear Windom Hood, and have found the ZPack's Goose Hood to be the most comfortable. Note that down hoods are not suitable for wearing while hiking in wet conditions.
Weight and Packed Size
This bag is the most compact three-season bag we've ever tested. It packs down as small or smaller than hooded 40-degree bags.
The ZPacks 20 Degree is very comfortable for a superlight backpacking bag. Don't expect to sprawl about like you would in a gigantic rectangular car camping bag. The main thing we find that reduces comfort is a restrictive hood that pinches or irritates your face when fully cinched. This bag skips the hood problem and its elasticized neck drawcord is comfortable; not as luxurious as the overstuffed collar on Katabatic Gear Quilts, but comfortable nonetheless.
Fixed girths sleeping bags suffer from limited versatility. They can't adapt to additional clothing layers like winter down jackets. This bag is intended for three-season use. Consider a quilt if you want one bag for three-season conditions and for winter when used with down clothing.
This bag has no significant drawbacks. The model we tested did not have a closure around the zipper but ZPacks has since added a small velcro tab to relieve stress from the zipper and prevent the bag from opening at night. Based on the photo below this looks more secure than most velcro closure found on bags we've tested, but may not be as secure, as durable, or as comfortable (velcro can irritate your skin if not closed or positioned properly) as a snap. We believe the best closure system is found on the Feathered Friends "Light Flight" series. Those bags use a single snap closure. This is a very minor nit-picky point.
Another one: most of the sleeping bags we've tested use thin static cord for the hood and neck closure. This bag uses a thin elastic, which is more comfortable than static cord but may not be as durable in the long-term. This is a very minor potential drawback; if the cord fails you can easily re-thread it with a cord or elastic of your own.
ZPacks offers their sleeping bags in an 800-fill hydrophobic down option. Based on preliminary field testing OutdoorGearLab does does not believe treated down is a viable alternative to synthetic insulation and is concerned about the long-term durability of treated down when compared to untreated down. If treated down does prove to be durable in the long-term then it presents a gigantic leap forward for the outdoor industry. At this time, however, we are hesitant to recommend treated down. See more about hydrophobic down and our plans for testing it here.
We gave this bag a bonus point in its Feature score for the awesome cuben fiber dry bag stuff sack that comes with the bag. This is the best stuff sack that we've ever seen included with a sleeping bag. It's waterproof, weighs half an ounce, is durable, and is functionally airtight, i.e. if your backpack was submerged your sleeping bag should remain dry. The same sack that comes free with your bag costs $21 on ZPacks' online store.
At $345 this is an excellent value. It's close to $100 less than the best hooded bag we've tested (Feathered Friends Hummingbird) and far less than $500 sleeping bags such as the Marmot Plasma and Sierra Designs Cloud. This bag offers higher performance for backpacking and costs less. And comes with an awesome stuff sack. Exceptional value for a high performance product that could last a decade or more.
How To Get It
ZPacks sleeping bags are not currently sold by major online retailers or outdoor stores. Choose your preferred warmth and weight at www.zpacks.com Read an interview transcript with ZPacks founder Joe Valesko here.
— Max Neale
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Most recent review: August 6, 2013
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