How to Choose Sleeping Bags for Backpacking
Rab Mythic Ultra 180 Sleeping Bag
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Delivering pioneering protection for those who need to make every gram count, the Rab Mythic Ultra 180 sleeping bag features 900+ fill-power down and heat-reflective Thermo Ionic Lining Technology.
Shop newer versionKey Details
Fill
900+ fill-power goose down
Weight
14.1 ounces
Temperature Rating (F)
32 degrees (F)
- Shell fabric is superlightweight 7-denier ripstop nylon
- Liner fabric is superlightweight 7-denier ripstop nylon with heat-reflecting Thermo Ionic Lining Technology (TILT) to boost warmth
- 900+ fill-power European goose down with Nikwax fluorocarbon-free hydrophobic finish
- Down is RDS-certified
- Weight-saving baffle construction prevents down from shifting and migrating
- Trapezoidal chamber design helps to eliminate cold spots
- Proportionally designed differential cut
- Antisnag bonded zip guard
- Angled foot box
Imported.
Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.
Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
View all Rab Backpacking Sleeping BagsEach bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.
| Best Use | Backpacking |
|---|---|
| Tested Lower Limit | 5 degrees (F) - ISO |
| Tested Comfort | 35 degrees (F) - ISO |
| Temperature Rating (F) | 32 degrees (F) |
| Temperature Rating (C) | 0 degrees (C) |
| Weight | 14.1 ounces |
| Ultralight | Yes |
| Shell | Nylon |
| Zipper Location | Left |
| Insulation Type | Down |
| Water-Resistant Down | Yes |
| Fill | 900+ fill-power goose down |
| Fill Weight | 180 grams |
| Sleeping Capacity | 1-person |
| Lining | Nylon |
| Sleeping Bag Shape | Mummy |
| Gender | Unisex |
| Sustainability | Down certified to the Responsible Down Standard (RDS) |
Buying Advice
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Mark F.
Tardis RAB Bag
1 year ago
The first thing that strikes you taking the bag from its dry bag (nice touch) is the immense loft from something so small in size. It kept filling up beyond what I thought possible. Next is the quality. It might be ultra light weight, but every element feels just right. The bag reduces grammes in several techy ways, but it's the shiny interior that stands out. Imagine a breathable cloth version of one of those emergency foil blankets they throw round marathon runners as they finish. Warmth is excellent. First time out was -8°C which is right at the edge of what RAB says is meant to be perfectly comfortable and - yes! - I'd say that was a cautious rating. The baffles and drawstrings are simple and the zip is small, but I found these all worked intelligently and was a good balance for what is a seriously featherweight bag. I'm struggling to find a negative in the bag itself. Price is expensive, but it's a RAB bag you're buying - and top of the line.
Originally posted on Rab
Inge L.
It’s a fantastic sleeping bag.
5 years ago
It’s a fantastic sleeping bag. I love it, love the small zipper, instead of a full lenght - it’s means I never end in a situation where the sleeping bag has come apart early in the morning and putting it together wakes me up completely. Too I love the inside collar, that means it can be used in various temperatures and winds. And the material is super nice, a cool feeling to sleep in cutting edge technology. Too the hood is perfect, it has meant I no longer bring a hat for sleeping, which I did before, also during summer. The stuff sack is fitting, and water proof, and it’s nice that it comes with a storage sack. In future I will start not not use the stuff sack to save the down. And even that I used it a lot without liner - it’s fresh still, it’s nice to the skin and warm the minute I get into it, with this bag I don’t need sleeping clothes at least not during summer. Only thing I look forward to is the official temperature rating of the sleeping bag.
Originally posted on Rab
Cathie H.
I can't believe how light
4 years ago
I can't believe how light and yet well constructed this product is. The technology is amazing, although I am yet to try it out so I can't comment on its warmth overnight.....
Originally posted on Rab
Bryn M.
Awesome quality inside and out
1 year ago
Awesome quality inside and out & really warm for the weight!
Originally posted on Rab
Paul V.
Ultra light and warm as
5 years ago
Ultra light and warm as advertised, worth every penny.
Originally posted on Rab
Siyuan X.
11 months ago
Originally posted on Rab
Coran G.
2 years ago
Originally posted on Rab