Kelty Cosmic Down 20 Sleeping Bag Review
The Cosmic has been a staple of Kelty's backpacking range for years, and it is about as known a quantity as a down bag on Amazon gets. It is a closed, hooded bag that delivers its rating however you sleep, and it is heavy and bulky for a bike.
The verdictA warm, closed, forgiving bag at a fair list price, with the bulk that 550FP down brings. Buy it for restless sleep and cold nights, not for a small seatpack.
The Regular Cosmic Down 20 holds 464 g of 550FP down in a bag Kelty lists at 2 lb 7 oz, about 1.1 kg. Kelty sells it as a 20°F (-7°C) bag, the ISO figures REI lists are 31°F (-0.5°C) comfort and 21°F (-6°C) limit, and the Amazon listing gives the same 21°F limit. The comfort figure is the one to plan around, and it makes this a near-freezing bag rather than a summer one.
It is a closed tube with a hood, a full draft tube along the zip and a draft collar at the shoulders, so it keeps its warmth when you roll over. Two locking sliders let you open it from the feet on a mild night. Kelty calls the cut semi-rectangular and REI calls it a mummy, and the Regular's 158 cm shoulder girth is roomier than a close-cut mummy, though one heavier Amazon owner still found it tight across the arms.
The cost on a bike is volume. Kelty's stuff sack for the Regular measures 20 x 33 cm, roughly 10 litres, which is most of a 14 litre seatpack before the pad goes in, and 550FP down needs more space than higher fill power down for the same warmth. Riders with a large bar roll can carry it there, and riders on a small seatpack should look at a quilt instead.
Owner reports on Amazon US sat at 4.6 stars across 110 ratings for the Regular when we checked in October, and REI's own reviews were cooler at 3.8 stars across 49. The REI complaints we read centre on a zip that sticks when worked from inside, and two one-star reports describe seams leaking down within a couple of trips. The Amazon listing says Kelty covers the bag with a limited lifetime warranty.
What works
- ISO comfort near 0°C, with a hood
- Draft tube and collar block drafts
- Fair list price for tested down
What doesn't
- 1.1 kg is heavy for bikepacking
- Roughly 10 litre stuff sack size
- Some owners report a sticking zip
Buy it if
Riders who turn over at night and want a hood and a tested rating near 0°C, plus a big seatpack or bar roll to carry it
Skip it if
Your whole sleep system has to fit a small seatpack, or you count grams, because 550FP down costs both weight and volume
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