Therm-a-Rest Hyperion 20 Review
Compare prices at 2 resellers Pros: Very lightweight, small packed size, high-quality down
Cons: Tight-fitting mummy bag, not very warm, expensive
Manufacturer: Therm-a-Rest
Our Verdict
Compare to Similar Products
 This Product
Therm-a-Rest Hyperion 20 | |||||
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| Awards |  |  | | ||
| Price | $399.95 at REI Compare at 2 sellers | $489 List $439.00 at Feathered Friends | $330 List Check Price at Amazon | Check Price at Backcountry Compare at 3 sellers | $118.96 at Backcountry Compare at 2 sellers |
Overall Score  |
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| Star Rating | |||||
| Pros | Very lightweight, small packed size, high-quality down | High-quality down, warm, lightweight | Comfortable, lightweight, excellent materials, not constricting | Light and compressible synthetic, keeps you warm when wet | Comfortable, inexpensive, recycled materials |
| Cons | Tight-fitting mummy bag, not very warm, expensive | Sizing not for everyone, fabric is a bit noisy | Comforter sometimes does not stay tucked in | Bulkier packed size, heavier, small fit | Heavy, bulky |
| Bottom Line | This super-lightweight, compact bag is a great choice for fast and light, warm-weather adventures but does sacrifice some comfort and warmth for weight | This high-end bag will keep you warm and comfortable from Spring to Fall in all conditions | A great, high-quality choice at a relatively low price for those looking for a lightweight bag that doesn't sacrifice comfort | An inexpensive and versatile synthetic bag, this is an excellent choice for breaking into backpacking | This well priced synthetic bag is a great choice for your car camping needs |
| Rating Categories | Therm-a-Rest Hyperi... | Feathered Friends E... | Sierra Designs Clou... | The North Face Cat'... | Marmot Trestles Eli... |
| Warmth (25%) | |||||
| Weight (25%) | |||||
| Comfort (20%) | |||||
| Packed Size (15%) | |||||
| Features (15%) | |||||
| Specs | Therm-a-Rest Hyperi... | Feathered Friends E... | Sierra Designs Clou... | The North Face Cat'... | Marmot Trestles Eli... |
| ISO/EN Comfort Rating (F) | 32 F | 20 F (not EN rated) | 26 F | 22 F | 20 F |
| Fill Type | 900-fill-power Nikwax Hydrophobic goose down | Goose down | PFC-Free DriDown | Heatseeker™ Guide synthetic insulation | HL-ElixR synthetic fibers |
| Measured Weight (in lbs) | 1.2 lb | 1.7 lb | 1.7 lb | 2.5 lb | 2.8 lb |
| Total Weight (oz) | 19 oz | 27.5 oz | 27.4 oz | 40.2 oz | 44 oz |
| Fill Power | 900 | 950+ | 800 | Synthetic | Synthetic |
| Women specific features | This bag comes in a "Short" length, which is a standard women's size | Extra fill in footbox and chest | More insulation per square inch than men's version | Women's specific cut | Women's specific fit |
| Fill Weight (oz) | 12 oz | 17.3 oz (medium) | 14.8 oz | Unspecified | Unspecified |
| Material | 10D Nylon RipStop w/ DWR | Pertex Endurance UL | 15d nylon risptop | 20D Nylon Ripstop/taffeta | 20-denier recycled ripstop polyester |
| Neck Baffle | No | Yes | No | Yes | Yes |
| No | No | No | No | Yes | |
| Sleeping Pad Sleeve | Removable attachment straps | No | Yes | No | No |
| Zipper Length | 35 in | 62 in | N/A | 59 in | 53/15" |
| Shoulder Girth | 55 in | 54 in | 59 in | 58 in | 58 in |
| Hip Girth | 48.5 in | 56 in | 58 in | 58 in | 58 in |
| Foot Girth | 36 in | 38 in | 39 in | 40 in | 45 in |
| Stuff Sack included? | Compression sack and storage bag included | Stuff sack and storage bag included | Stuff sack and storage bag included | Compression sack and storage bag included | Stuff sack and storage bag included |
Our Analysis and Test Results
The Hyperion is a great choice for warm-weather, lightweight backpacking adventures. If you’re looking to go fast and light this could be the bag for you.
Performance Comparison
Warmth
Because it is a unisex model, the Hyperion’s temperature rating is different from the other bags in this review. Therm-a-Rest rates this bag to the EN “Limit” rating, which in this case is 20F versus the “Comfort” rating of 32F. This is different from the other women’s specific bags we’ve tested, which use the “Comfort” rating in their naming conventions, but seems to be the way that Thermarest rates all their bags. This is definitely something to note when you’re comparing the Hyperion to other products in this review. This bag’s Comfort rating is to 32 F. We took it out on a chilly September night and we’d say that rating is just about right. As the temperatures dipped towards freezing in the wee hours of the morning we felt chilly but never cold. We like the Hyperion’s half zip as it prevents drafts coming through the zipper and its snug hood does the same.
Weight
The Hyperion blows the competition out of the water in this category. Weighing only 19 ounces it’s half a pound lighter than its closest competitor. As we mentioned in the warmth section, the Therm-a-Rest Hyperion trades off some of its warmth for those extra ounces.
Comfort
Again, in an effort to slim down the ounces, the Hyperion has a trimmed down silhouette that makes for quite a snug fit. We tested the “Small” size and our 5’5 tester just barely fit length-wise. She was able to get the hood over her head and was quite cozy; however, we think most folks who aren’t used to a snug mummy fit will not feel comfortable in this bag. There is very little legroom (your legs are essentially pinned together in the bag), but there is an articulated foot box so your feet don’t feel squished. This bag is all about its low weight, and you sacrifice comfort noticeably for fewer ounces. We do think that this snug fit helps keep the warmth in. This bag also only has a half-length zip and some people will find this less comfortable as well.
Packed Size
This bag packs down to a tiny little capsule and gets really small. We like that the Therm-a-Rest Hyperion comes with a compression sack to make it even smaller than a traditional stuff sack would.
Features
The Hyperion’s features are all about weight savings, which we think is great. It has a really high quality down fill of 900, which increases its warmth to weight ratio, and the half-length zipper shaves a few grams. This bag also comes with “SynergyLink™ Connectors” that are essentially removable straps you can use to attach your bag to your sleeping pad if you’re one to roll off your sleeping pad. We really like that they’re removable and appreciate the simple attachment system.
Value
Even though the Hyperion has high-quality materials, we think the price tag is a little steep. There are other products in this review that you get a lot more bang for your buck than with the Hyperion. However, it is one of the lightest bags we’ve found that’s sized for smaller people. If the conditions and mission are right, it could be worth the money for you.
Conclusion
The Therm-a-Rest Hyperion is a great choice for fast and light summer adventures. This is a very snug-fitting mummy-style bag that’s comfort rated to 32 F, so be sure you’re ready to sacrifice a bit of comfort and warmth for a tiny, lightweight package. If you’ll be spending lots of time carrying your stuff around, and don’t think the temperatures will go below freezing, this bag could be a great choice for you, if you’re willing to pay the price.
— Jessica Haist
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