Top Rated: Nordisk Abel +10 Sleeping Bag (8.1 / 10)
Category: Modular Sleeping Bag 2: Best 1 Season and 3 Season Outer
Scramble's Recommended Sleeping Bag System
The military modular system uses 2 bags: a lighter "patrol" bag (down to 0°C) and a medium-weight cold weather bag (down to -15°C) which combine for extreme cold (down to -30°C, but a total weight of nearly 3kg).
Scramble's recommended "modular" system uses 3 bags, is lighter and a little more flexible (better in hotter, arid conditions, yet still good down to around -25°C, the extreme combination weighing just over 2kg). This summary is for the 1 Season (wet weather) and 3 Season Outer: Sleeping Bag 2.
Review Summary
Finding a lightweight 1 season synthetic bag is not a problem. Marmot, The North Face, Mountain Hardwear and Vaude all make such bags. Vaude's 630g Sioux 100 SYN is a good example, as is Nordisk's ultralight Oscar, weighing in at just 332g. However, none of these bags will host another lightweight bag inside them. Their effectiveness relies on their confined mummy-shape reducing the capacity for "dead air", yet it's this "empty space" we require when we want an inner bag to loft and achieve its optimal thermal efficiency. The ideal modular 3 season outer bag needs to be somewhere between a strict mummy-shape and a rectangular design. The Abel +10's (and by extension, the Gorm +10's) rare "egg-shaped" design fits the bill perfectly.
On its own the Abel +10 is a comfortable and effective warm / wet weather sleeping bag and when paired with an ultralight down bag such as Alpkit's Cloud Cover, the Abel +10 will provide a good nights sleep down to 0°C. At some point outdoor manufacturers will embrace the modular approach; when they do Nordisk will have earned themselves a decent headstart; with their thoughtful, unfussy design the Abel and Gorm +10s will make excellent templates for the ideal lightweight outer bag. The Abel +10 is Scramble's top pick for bag #2 in our recommended modular system: The 1 Season "Jungle Bag" and 3 Season Outer.