At a specified weight of 16 ounces for the regular length (20 ounces for the long length), the Marmot Atom sleeping bag is the lightest bag in Marmot’s lineup. The Atom features Marmot’s 850 plus fill power down and a Pertex Quantum shell. Marmot rates the Atom as a 40 degree F bag and lists a total loft of 4 inches. The Atom uses sewn through construction and features continuous tubes that wrap around from the bottom to the top of the bag. The Atom has a half zipper and a draft tube.
We recently acquired a long length Atom for testing. This bag weighs in at 22.4 ounces, 2.4 ounces above the manufacturer’s specified weight. Measured loft on this bag averages 4.1 inches and was measured at shoulders, hips and near the foot box. The included stuff sack adds another 1.3 ounces. The bags stuffs down to an impressively small volume; about the size of a large cantaloupe.
At nearly 6 feet 5 inches, I am a good person to test the length on a long bag. The Atom is plenty roomy for me, both in girth and length. I can easily cinch up the hood while still leaving pleny of room for my feet in the footbox.
I am anxious to get the Atom out into the field and compare its warmth, comfort and wet weather perfomance to some of its closest competition. Will the sewn through construction make it difficult to stay comfortable as the temperatures approach freezing? How will the Pertex Quantum shell perform in diverse conditions? Will the half zipper be a handicap when using the bag in warm weather?
Features and Specifications
- 850 plus fill power down
- 22.4 ounces for long length (20 ounces manufacurer’s spec weight, 16 ounce spec weight for regular)
- Measured loft averages 4.1 inches (manufacturer’s spec 4 inches)
- Pertex Quantum N-090 taffeta shell
- Half length zipper
- Draft tube
- Fully closable mummy hood
- Manufacturer’s temperature rating of 40 degrees F
- MSRP $249 regular length, $269 long length