What is the Mythic Ultra 180?The Mythic Ultra is one of the lightest and most packable sleeping bags available thanks to the incredible 900+ fill-power down and ultra-techy 7D outer fabric. It's aimed squarely at those counting every gram while trekking, backpacking, running, mountaineering, fastpacking, etc.
What is it made of?Insulation: The most important aspect of the Mythic is the exceptionally high-quality 900+ fill-power goose down insulation. The quality of this insulation means the Mythic will pack down far smaller than most sleeping bags, is far lighter and requires less insulation to equal the same warmth as cheaper alternatives. This down is then treated with a Nikwax hydrophobic coating, meaning if it happens to get wet, it'll absorb less water and stay warmer for longer. This doesn't make it waterproof by any means, but it does mean it'll stand a chance if you spill your morning coffee over yourself.
As if the quality wasn't enough to persuade you, the down is all R.D.S certified, meaning it comes from birds which have not been live-plucked and have lived a free-range existence. Not only is the down ethically sourced and of the highest quality, but Rab also incorporates clever internal fabric technology to further boost warmth, but more about that below.
Fabrics: I know we usually start on the outside, but bear with me on this one. The inner fabric is a super-lightweight 7D ripstop nylon with thermo ionic lining technology, or TILT for short. This clever technology utilises titanium-coated nylon fibres to create an almost 'foil blanket' effect whereby your natural body heat is reflected back to you, increasing warmth by 32% without adding a gram of weight. And no, it doesn't feel like a foil blanket, it feels exactly the same as a normal sleeping bag fabric! The outer fabric is made of exactly the same material but without the clever TILT tech. The combination of these lightweight fabrics and the high-quality insulation means the Mythic is significantly lighter and more packable than most alternative sleeping bags with a similar warmth rating.
What are its features?The Mythic isn't loaded with features as it's designed to be as light and packable as possible, but it does have some performance-boosting additions. There's an internal insulated collar within the hood designed to trap heat, an angled footbox to prevent your feet squashing the down and reducing its efficacy and a weight-reducing 1/2 length zip with a glow in the dark zip pull. Even the included compression sack is made from lightweight materials!
- Super lightweight 7D Ripstop Nylon Outer Fabric
- Super lightweight 7D ripstop nylon with thermo ionic lining technology (TILT), heat-reflecting to boost warmth
- 900+FP R.D.S Certified European Goose Down
- Rab Fluorocarbon free Hydrophobic Down, developed in conjunction with Nikwax
- Weight saving baffle construction, preventing down shift/migration
- Trapezoidal chamber design to eliminate cold spots
- Proportionally designed differential cut
- Anti-snag bonded zip guard
- Ergonomically designed internal collar and hood
- Angled foot box
- ½ length YKK 3 coil main zip with noctilucent puller
- Lightweight Dry bag compression stuff sack
- Cotton storage sack
- Filled in Derbyshire UK
- Left zip only
How warm a sleeping bag do you really need? We’ve tried to help you by grouping our sleeping bags by their recognised comfort ratings. These are the ratings supplied by the brands that indicate the temperature at which you will remain comfortable whilst sleeping on an insulated sleep mat. After all, comfort is what you want when it’s cold and wet outside, and you’re all tucked up in your nice warm sleeping bag.
We always recommend that you choose your bag according to the coldest conditions you will experience; you can always unzip a bag if it is too warm, but trying to sleep when you’re too cold is just miserable. Bear in mind that we are all individuals, so we all feel the cold differently and that our own resistance will fluctuate depending on a whole load of factors, including how much we have eaten, whether we have consumed alcohol, whether we need a wee or what kind of mood we are in!
Sleeping bags do not generate heat; they only trap the heat we produce, so it is vital that you get into your bag when you are giving off warmth, don’t go to bed when you are cold, have a hot meal or a hot drink or do some brisk exercise to get you nicely warmed up.
Traditionally sleeping bag manufacturers provided their own temperature ratings based on their experience, the product's intended end-use and the perceived environment. However, each brand tested their bags in different ways, and it was hard to find a fair comparison between models. So, in 2005 a European standard for sleeping bag temperature ratings, EN 13537, was introduced to give consumers a comparable guide to sleeping bag performance across a range of brands and models. The ratings have four different temperature ratings to give you an indication of the bag's performance.
Comfort Rating: This is the temperature at which an average female should experience a comfortable night’s sleep. On average, women sleep colder than men, so this rating is some degrees above the "comfort lower limit" for a man.
Comfort Limit Rating: This is the lowest temperature at which an average male should experience a comfortable night’s sleep whilst laid down in a curled up position.
Extreme: This is a survival rating where the user is likely to suffer health damage such as Hypothermia. It should be treated with the utmost caution and not be relied on for general use.
However, the EN 13537 European Standard does not apply to down-filled sleeping bags with a fill weight of more than 800g; for those bags, you will have to rely on the manufacturer's experience and technical expertise, which is often more accurate!
Most reputable brands still use their own rating system alongside EN 13537, for instance, Mountain Equipment's “Good Night’s Sleep” and Rab’s “Sleep Limit”. These ratings are often the most accurate guide to the overall performance of a sleeping bag being used by an average outdoor enthusiast because they are based on years of expedition heritage, field trials, technological experience, and constant feedback.
But please bear in mind that all ratings are only a guide and, as mentioned earlier, there are a huge range of factors that can affect your comfort; if you are just not sure, it is always wise to go for a warmer model.
The biggest difference you can make to your overall comfort is to use an efficiently insulated sleeping mat. Once you get inside your sleeping bag, you instantly compress all the filling beneath you, greatly reducing its efficiency. Therefore using a quality sleep mat will ensure you are properly insulated from the cold ground, and you will be a lot more comfortable... Basically, there is no point in buying a top-quality sleeping bag if you are just going to lie down on the floor.