Marmot Lithium MemBrain 0F Sleeping Bag Review

Features:

From Marmot, "We combine 850+ fill goose down and two-layer MemBrain® waterproof fabric with no-a nonsense design ethic to create this extremely lightweight, professional-level bag. For sleeping in rapidly changing mountain conditions in temperatures down to 0° F, this is our lightest, most durable offering."

The Marmot Lithium MemBrain® sleeping bag is filled and finished in the U.S.A. (Santa Rosa, CA). It is filled with certified 850+ fill power down, the best weight-to-warmth down on the market. The left hand zip, EN tested Lithium MemBrain® bag features a Pertex© Shield® waterproof/breathable shell, Pertex© Microlight® lining, down filled collar, and stretch tricot baffles. Also features a full length zipper and zipper garage, nautilus 6 baffle hood, hood draw cord, insulated draft tube, and Velcroe®-free face muff. The Marmot Lithium MemBrain® comes with both storage and stuff sacks.

Specifications:

Length: Fits up to 6'0"
Size on Hip: 58 in. (147.3 cm)
Size on Foot: 40 in. (101.6 cm)
Main Material: MemBrain®2L 100% Nylon Ripstop 2.0 oz/yd
Lining Material: 20 Denier 100% Recycled Polyester Mini Ripstop
Overall Weight: 2 lbs 14 oz (1330 g)
Fill Weight: 28 oz (794 g)
Insulation Material: 850+ Fill Power Goose Down

Initial Thoughts (11/13/12):

My wife and I must own over a dozen sleeping bags. I believe there is no such thing as too many sleeping bags. They are as varied as the conditions we encounter on any given adventure. Some are for warm adventures, while others are for frigid adventures. I purchased my latest sleeping bag, a Marmot Lithium MemBrain® with the intent of it being my main cool weather winter bag while doubling as my wife's shoulder season bag.

I immediately noticed how much loft the Marmot Lithium MemBrain® sleeping bag has. It definitely looks the part of a high quality winter bag. The lofted height of the bag ranges from 6 to 7.5 inches. Whether stored loosely in the storage bag or stuffed tightly in the stuff sack, the Lithium MemBrain® quickly lofts to full height. When resting inside the bag, it feels comparable to being under a very thick down comforter. For a winter bag, I love how warm and substantial it feels. At an advertised weight of less than three pounds, it is quite impressive. On my scale, the Lithium MemBrain® weighed in at 3 pounds 2 ounces (w/out stuff sack which is an additional ounce). It's a little disappointing that Marmot is consistently off on the published weights of their gear. In this case, hopefully it means the bag was overfilled.

The outside fabric of the bag feels stiffer than that of a typical mummy bag. This is due to the waterproof MemBrain® fabric which should make this bag fantastic in winter conditions. It should work great sleeping under the stars or in a snow cave. One drawback of the MemBrain® fabric is that it is much slower to let air escape when compressing the bag for packing. I find it very difficult to stuff the bag into the small (approximately 12L) stuff sack Marmot includes. It's not impossible, but I think a larger compressible stuff sack might be a better way to go. Once the Lithium MemBrain® bag is completely stuffed in the sack it is possible to compress it further by about 6 inches (~37%).

The hood of the Lithium MemBrain® bag is very comfortable and should prove warm this winter. I am not impressed with the draft tube, which seems to be under filled with down. I am not a big fan of draft tubes to begin with and I think the Lithium MemBrain® sleeping bag would be better without it altogether.

Overall the bag feels like a great investment, as it should with a street price of $391-$559. I am eager to try it out this winter on a few snow camping trips. My wife has already used it a couple times late in the summer and again in the early fall. She sleeps very cold and both times she was way too warm. Luckily with the full length zipper it is fairly easy to regulate temperature as needed.

Initial Field Test:

Coming soon...

Available from amazon.com.