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Therm-a-Rest Saros 20 Review

A comfortable bag that's borderline too heavy for backpacking.
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Price:  $180 List | $179.95 at Amazon
Pros:  Super comfortable, excellent build quality, foot warmer pocket
Cons:  Super heavy, extremely bulky, there are cheaper bags for car camping
Manufacturer:   Therm-a-Rest
By Jack Cramer ⋅ Review Editor  ⋅  May 19, 2019
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47
OVERALL
SCORE


RANKED
#8 of 9
  • Warmth - 20% 6
  • Weight - 20% 1
  • Comfort - 20% 7
  • Packed Size - 15% 1
  • Versatility - 15% 7
  • Features & Design - 10% 7

Our Verdict

Designing a backpacking sleeping bag is a tricky balancing act between warmth, comfort, and weight. In the case of the Saros, we believe the scales are tipped too far in favor of warmth and comfort. It's certainly both of these. However, in achieving this warmth and comfort, it unfortunately became heavy and bulky. Its 3.84-pound total weight is heavy enough that we don't consider it a great choice for backpacking. The Saros is still an impressive sleeping bag, but it's better suited for activities where a boat, car, or draft animal carries its weight, rather than on your shoulders. For real backpacking, the Nemo Kyan is a similarly priced budget sleeping bag that weighs only half as much.


Compare to Similar Products

 
Awards  Best Buy Award   Best Buy Award 
Price $179.95 at Amazon$199.95 at REI
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$169.95 at Backcountry$169.95 at Backcountry
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$159.95 at REI
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Overall Score Sort Icon
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Star Rating
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Pros Super comfortable, excellent build quality, foot warmer pocketAwesome warmth-to-weight ratio for the price, very compressible, tons of venting options, nice compression sack includedThick synthetic insulation, well-balanced performance, easy to use zipper, included stuff sackCheap, anti-snag zipper, sturdy materials, versatile synthetic insulationInexpensive, burly, decent warmth, roomy fit
Cons Super heavy, extremely bulky, there are cheaper bags for car campingNot as warm as its temp rating, no draft collar, uncertain durabilityBulkier than expected, mediocre warmth-to-weight ratioModerate warmth-to-weight ratio, doesn't compress well, limited extra featuresHeavier than average, bulky, no storage sack, no compression sack
Bottom Line A comfortable bag that's borderline too heavy for backpacking.An exceptional deal for a lightweight bag that excels in wet conditions.A simple but effective synthetic mummy bag.An affordable workhorse with solid all-around performance.A legit backpacking sleeping bag that won't cost you an arm and a leg.
Rating Categories Therm-a-Rest Saros 20 NEMO Kyan 35 The North Face Cat's Meow 20 Mountain Hardwear Lamina 30 Kelty Cosmic 20
Warmth (20%)
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6
Weight (20%)
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3
Comfort (20%)
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7
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7
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6
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6
Packed Size (15%)
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Versatility (15%)
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Features & Design (10%)
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Specs Therm-a-Rest Saros... NEMO Kyan 35 The North Face... Mountain Hardwear... Kelty Cosmic 20
Measured Weight (size long, in lbs) 3.84 lbs 1.89 lbs 2.39 lbs 2.28 lbs 2.63 lbs
Temperature rating (F) 20 F 35 F 20 F 30 F 20 F
EN lower limit (rating for men)/ EN Comfort Rating (rating for women) 20 / 31 F 35 / 46 F 22 / 33 F 27 (lower) F 19 (lower) F
Manufacturer claimed weight of size Regular (lbs) 3.50 lbs 1.69 lbs 2.25 lbs 2.17 lbs 2.41 lbs
Compression/Stuff Sack Weight (oz) 1.2 oz 2.4 oz 4.0 oz 3.7 oz 0.8 oz
Compressed Volume (L) 15.5 L 6.6 L 11.4 L 8.6 L 8.7 L
Fill Synthetic - eraLoft Synthetic - Primaloft Silver Synthetic - Heatseeker Guide Synthetic - Thermal.Q 600FP Down (83%) / Polyester (17%)
Hydrophobic down? N/A N/A N/A N/A Yes
Fill Weight (Reg oz) 39 oz 12 oz 26 oz Unknown 18.2 oz
Shell material 20D Polyester Ripstop Ripstop nylon (20D) 20D Nylon Ripstop Ripstop nylon (30D) 20D Nylon taffeta
Neck Baffle Yes No No No Yes
Small organization Pocket Yes No Yes No Yes
Zipper 3/4-Length Side Full-length / Side Full-Length Side Full-lengh / Side 3/4-Length Side
Shoulder Girth (Reg) 63 in 62 in Unknown 60 in 64 in
Hip Girth (Reg) 61 in 57 in Unknown 58 in 60 in
Foot Girth (Reg) 46 in 46 in Unknown
Stuff or compression sack included? Stuff Compression Compression Compression Stuff
Storage sack included? Yes Yes Yes Yes No
Water resistant shell? DWR DWR No DWR No
Total Weight (Long size, in oz) 61.4 oz 30.2 oz 38.2 oz 36.4 oz 42.0 oz
Manufacturer claimed weight (Long, oz) 60 oz 30 oz 39 oz Not listed 42.7 oz

Our Analysis and Test Results

Therm-a-Rest is deservedly known for making outstanding sleeping pads. Their sleeping bags, however, have yet to earn a similar reputation. We recently tested their comfy Saros and ultralight Hyperion models. Both are impressive but still a step behind our favorite bags in their respective categories. Read on to learn why the Saros missed out on a budget sleeping bag award.

Performance Comparison


Therm-a-Rest has mastered backpacking sleeping pads. However  they seem to still be figuring out sleeping bags.
Therm-a-Rest has mastered backpacking sleeping pads. However, they seem to still be figuring out sleeping bags.

Warmth


The Saros contains 39 ounces of synthetic eraLoft insulation. This amount is considerably more insulation, by weight, than most other backpacking sleeping bags. Unfortunately, however, this insulation doesn't make it considerably warmer than other backpacking sleeping bags. Its 20°F lower limit rating (EN) seemed accurate compared to other bags. This rating, however, doesn't set it apart from the pack. We consider both the Big Agnes Husted 20 and The North Face Furnace to be warmer.

EN tested bags receive three ratings: a comfort  limit  and extreme rating. Most users will be happy near the comfort rating. Staying comfortable at the limit rating usually requires a quality sleeping pad and good layering.
EN tested bags receive three ratings: a comfort, limit, and extreme rating. Most users will be happy near the comfort rating. Staying comfortable at the limit rating usually requires a quality sleeping pad and good layering.

Weight


A consequence of this bag's ample insulation is that it's disappointingly heavy. On our digital scale, a size long weighed 3.84 pounds. This figure is more than double that of the lightest budget sleeping bags, like the Nemo Kyan 35 and Klymit KSB 35. It is heavy enough that we recommend the Saros primarily for car camping and only occasional backpacking.

Comfort


One thing this bag has going for it is its comfort. It has some of the roomiest dimensions of any mummy bag. We're also big fans of the 20-denier polyester taffeta fabric which manages to be glossy while still feeling soft. The Saros also has a foot warmer pocket to keep your toes cozy. The comfort could be slightly improved, however, if the hood drawstring were an elastic cord rather than a shoelace-like string.

Compressed inside its stuff sack  the Saros is still too big to fit across the bottom of this large 75-liter backpack.
Compressed inside its stuff sack, the Saros is still too big to fit across the bottom of this large 75-liter backpack.

Packed Size


Another consequence of this bag's ample insulation is its bulky packed size. Using an after-market compression sack, we weren't able to squeeze it any smaller than 15.5 liters in volume. This model is more than double the size of the smallest budget sleeping bags. The simple drawstring stuff sack that it comes with is also an unfortunate shape that won't fit horizontally across the bottom of most backpacks.

Versatility


The Saros features a ¾-length main zipper that's okay at venting excess heat. It also has a fluffy neck baffle that's good for sealing heat in on frosty occasions. The synthetic insulation can be relied upon to maintain its ability to insulate if it gets wet. This bag, however, would score a little better in versatility if it had a longer zipper or another way to let heat escape on warmer nights.

Features and Design


This bag has perhaps the most accessory features of any budget sleeping bag we tried. Some of these are useful, others not so much. Many of our testers, for example, consider the sleeping pad attachment system unnecessary, but thankfully, it's removable. The stash pocket, in contrast, is an accessory feature that we happen to like for keeping a headlamp or phone handy.

The Saros has a zippered stash pocket on the right side of the bag.
The Saros has a zippered stash pocket on the right side of the bag.

Finally, the foot warmer pocket is a polarizing accessory. Some of our testers were rather fond of it. Others found it entirely unnecessary and thought the additional insulation needed would be more useful closer to your core than your extremities. With that said, it's up to you to decide if a small sleeve to tuck your feet inside is desirable.

Best Applications


Due to this bag's substantial weight and bulky packed size, we can't recommend it for extensive backpacking. Rather its superior comfort is best enjoyed while car camping or on shorter backcountry overnights close to the trailhead. It could also be a great bag for activities where weight isn't a huge issue, such as rafting or horse packing.

Our review team believes the Saros is too bulky and heavy for long-distance backpacking. However  it's great for car camping or shorter hikes near the trailhead.
Our review team believes the Saros is too bulky and heavy for long-distance backpacking. However, it's great for car camping or shorter hikes near the trailhead.

Value


Although the Saros doesn't provide great weight or packed size performance, it has high-quality materials and construction. Many of our testers found its accessory features a bit much, but there will be plenty of consumers that feel the opposite. For those that will fully appreciate its extra bells and whistles, it offers a decent value.

Conclusion


There's a lot to like about the Saros. It's undeniably comfortable and fitted with some clever accessory features. We are also impressed with the quality of its materials and construction. However, to supply this comfort and include these accessories, it becomes disappointingly heavy — so much so that we think it's too weighty for frequent backpacking. The Saros is still an awesome bag for car camping or short hikes, but you'll probably want a lighter, more packable bag for backcountry overnights.


Jack Cramer