Expanse Sleeping Bag

The Expanse Sleeping Bag is a hoodless ultralight down sleeping bag with interior cinch cords that adjust internal volume without compressing the down. It is cut with a mild, roomy taper: 30 inches across the shoulders, 27.5 inches at the knee, and a footbox with a 13.5 inch minimum inside width. 900 fill power ExpeDRY Muscovy down. 10D nylon with a DWR treatment inside and out. Comfort rated at 0F, 15F, and 30F, in Regular and Long. It is built for people who sleep badly in a narrow mummy bag and don’t want to deal with the pad straps of a top quilt. Does a roomier sleeping bag make you colder? Extra space inside a sleeping bag is extra air your body has to heat, and air you are heating but not touching is called dead air space. It does not insulate you, it just costs you calories and time to warm. A bag cut wide gives you room to move, but can also cause you to feel colder with the extra space your body heat has to keep warm. That is the tradeoff the Expanse was built to break. Make it roomy for comfort, then give the sleeper a way to remove the space they are not using when the temperature drops. How the interior cinch cords work Inside the bag are elastic drawcords set in adjustment zones: two in Regular, three in Long. Cinch one down and it reduces the internal volume of that zone, so there is less air for your body to heat. Leave them loose and the bag returns to its full roomy shape. A common way to use it: cinch the bag in closer around your lower body to cut dead air space, and leave the footbox open so your feet can move naturally. Why the cords are inside the bag and not strapped around the outside External compression squeezes the bag from the outside, which crushes down loft, and crushed down does not insulate. Loft is the insulation. Cinching a bag from the outside to make it more efficient works against the thing keeping you warm. The Expanse puts the cords inside instead, so they can reduce the air space without squeezing the down. And because the cords are elastic rather than fixed cord, a cinched bag still moves with you. Cinched does not mean pinned. Why it is hoodless Going hoodless takes weight and redundancy out of your kit & lets your layering system cover your head, which is how many experienced backpackers are already sleeping. Use your jacket hood, a beanie, or a balaclava instead.. Down distribution Down is distributed symmetrically through the bag, so warmth stays even as you move around at night. There is not a top or bottom side, so you can sleep with the zipper facing either direction. A single half-length side zipper with YKK No. 5 coil hardware lets you vent without opening the whole bag, and draft tubes run behind the zipper so the seam is not a cold line down your side. A dry bag and a long-term storage bag are included. Who it is for Backpackers who find mummy cuts restrictive Side sleepers and anyone who moves at night Thru hikers who want more comfort than a quilt gives them Backpackers who have tried a quilt and could not get the drafts under control Anyone who has decided that sleep quality is worth a few ounces on a trip they only get once or twice a year On the ratings We publish comfort ratings, which means the number is built to be comfortable at that temperature, not survivable at it. All models have been tested comfortably in field conditions at or below the listed ratings.