
RAB have produced two state of the art sleeping bags in the Mythic Ultra 180 and Mythic Ultra 360 sleeping bags. Utilising the same technology, both bags offer low weight, small pack size, Hydrophobic Down and the ground-breaking TILT technology – Thermo Ionic Lining Technology. The TILT in real simple terms brings elements of an emergency space blanket incorporated into the design of the bags.

Offering best performance at weight for any comparable bag, both the 180 and 360 have been my ‘go-to’ bags since early in 2020.
Quite simply, amazing levels of warmth for low weight.

The RAB Mythic 180 has 180g of 900+ fill power Hydrophobic down and a comfort limit of 0 degrees and a weight of 390g. It’s a perfect bag for warmer weather and any adventure when low weight, small pack size and warmth are important. Perfect for multi-day racing for Marathon des Sables or similar and, is brilliant for fastpacking adventures when travelling in a self-sufficient manner.

The RAB Mythic 360 has 360g of 900+ fill power Hydrophobic down and a comfort limit of -8 degrees and a weight of 620g. This bag utilises all the same technology of the 180 and quite simply is warmer and heavier. Just like the 180, it’s the perfect bag for racing and fastpacking adventures in colder and more challenging conditions.
Please read How To Choose A Sleeping Bag.
IN USE
Mythic Ultra 360
The recent 18-months have allowed me more time outdoors than ever before and almost weekly I have ventured outside on multi-day fastpacking adventures or overnight trips. The 360 and 180 have been on most of these trips offering low weight, small pack size and incredible warmth.

I am lucky, based in Norway, I get to fully experience the cold of winter and in summer, warm and comfortable nights.
An overnight fastpack in February and I was camping in -18 degrees on snow in a small one-man tent. The Mythic Ultra 360 with a comfort rating of -8 was not going to be enough for a cold night, however, I had planned accordingly carrying Merino base layers, down pants, and down jacket. When all combined inside the Mythic Ultra 360 I was cozy warm. This was an extreme test of the 360 and importantly, I think it’s important to understand how layering is an important element to the use of any sleeping bag. It offers incredible flexibility.

But the true test of the 360 has come on regular trips in Autumn and Spring when the temperatures are hovering around +5 to -5. In these situations, the bag has performed flawlessly providing low weight and incredible warmth all in a small package. The groundbreaking TILT really does perform and as mentioned earlier, it’s like adding a space blanket inside the bag. It’s heat reflective and therefore increases the internal warmth for minimal extra weight.
I consider the bag a game changer for its weight v performance but of course, this comes at a price. Expect to pay around £700 for this technology.
Using 7D ripstop nylon, TILT and excellent design, the Mythic Ultra 360 has been the most comfortable bag I have ever used. One would potentially think that just 360g of down would not be enough, especially for a -8 bag, but that is where the technology kicks in and that is why the price goes up. It’s the perfect bag alpinists, adventurers, and runners.
It has boxwall construction and trapezoidal baffles which allows the down to loft reducing cold spot risk. It has an ergonomically designed collar and hood that closes in around the head and neck reducing cold getting inside the bag and therefore allowing the warm air inside the bag no opportunity to escape. An anti-snag zip guard, angled foot box and short zip are additional features.
As you would expect, internal space is compromised, after all, this helps keeps the weight down. So, this may be a consideration, it’s suitable for someone up to 6-foot tall with comfort. After that, it would come down to personal comfort and needs. Shoulder width is 27 inches, hip width 21 inches and the foot width 16 inches.
FEATURES

The bag comes with a large cotton sack so you can store without compressing the down, it is also supplied with a compression dry bag. It has a ½ length zip on the left only. The down is Hydrophobic, so, it can get wet and retain warmth, an important feature. 7D Ripstop fabric and importantly the TILT technology is a USP to boost warmth thereby facilitating lower bag weight. Tested to EN1357:2016 standards, the Mythic Ultra 360 has comfort of -2, Comfort limit of -8 and an extreme limit of -27 (but I wouldn’t want to be in that situation!)
CONCLUSION
This is a high-performance bag and state of the art. If the cost is no problem and you require small size, low weight, and warmth, the RAB Mythic Ultra 360 should be on your list. It’s an amazing bag!

Mythic Ultra 180
At £550 the 180 has all the features of the 360 above and it has the same measurements: Suitable for someone up to 6-foot tall with comfort. After that, it would come down to personal comfort and needs. Shoulder width is 27 inches, hip width 21 inches and the foot width 16 inches.

It also has all the same features including the cotton storage bag, dry bag, 7D ripstop, TILT, 900+ Hydrophobic down and same great construction.
Quite simply, the Mythic Ultra 180 is a stripped down 360 designed for warmer temperatures and thus bringing even lower weight and pack size.
At 400g, it is perfect for racing or fastpacking when temperatures at night are expected to be 0 degrees or above, as such, it’s a perfect bag for Marathon des Sables or similar multi-day adventures. It’s also ideal for Mountain Marathon events and summer alpinism.
All the pros and cons listed above for the 360 are directly transferable for the 180.
FEATURES

The bag comes with a large cotton sack so you can store without compressing the down, it is also supplied with a compression dry bag. It has a ½ length zip on the left only. The down is Hydrophobic, so, it can get wet and retain warmth, an important feature. 7D Ripstop fabric and importantly the TILT technology is a USP to boost warmth thereby facilitating lower bag weight. Tested to EN1357:2016 standards, the Mythic Ultra 180 has a comfort limit of 0 degrees.
CONCLUSION
Low weight, amazing warmth and small size, the Mythic Ultra 180 is a bag for warmer temperatures when price is no issue and features are paramount. It’s a perfect bag for racing and fastpacking adventures and the Hydrophobic down gives peace of mind in poor weather conditions.
FINAL THOUGHTS
The RAB Mythic Ultra 180 and 360 bags are state of the art and work together with each other offering low weight and warmth for any adventure. I am fortunate to have both and therefore can switch between 180 or 360 based on weather conditions. However, all sleeping bags have greater flexibility when one adds layers. The 360 can be used in much colder temperatures with Merino and down layers. You could argue that this adds extra weight to the overall pack, but, if you are out in in -10 or lower, you will be carrying these layers anyway for day use.
The 180 is a lighter bag and again, adding a layer or multiple layers when inside will increase warmth. A prime example being a race like MDS, many take a very light down jacket for when sitting around, add this inside the bag and the warmth increases.
However, here in the RAB Mythic Ultra, remember the TILT works by reflecting heat, so, one would need to test and try what method provides the best warmth.
Ultimately, if you need a sleeping bag the 180 and 360 offer two great starting points and they should be a consideration.

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