Last updated: 07-Nov-18
By Luke Jarmey
When you carry a sleeping bag as a runner, you want it to be light… and I mean really light. However, as our multi day trail runs often take place in rather inhospitable environments, be it mountain, desert or just blooming wet n’ windy UK moorland, it’s critical that the warmth of the sleeping bag is sufficient for the climate in question.
So with this all in mind I was incredibly excited to get my mitts on Rab’s latest feather light offering, the Mythic 200. Labelled as having the ‘best warmth to weight ratio in the Rab range’, this seemed like a perfect contender for overnight summer mountain running adventures.
- EN ISO 23537-1:2016 Comfort: 6°C (43°F)
- EN ISO 23537-1:2016 Limit: 1°C (34°F)
- EN ISO 23537-1:2016 Extreme: -13°C (-8.5°F)
- Rab® Limit: 1°C (34°F)
- Pertex® Quantum 7 Denier Inner and Outer
- 900 Fill Power ethically sourced European Goose Down
- Rab® Fluorocarbon free Hydrophobic Down developed in conjunction with Nikwax®
- Weight saving baffle construction, preventing down shift/migration
- ¼ length YKK 3 coil main zip with noctilucent puller
- Internal collar and hood drawcord
- Super lightweight trims and features
- Angled foot box
- Dry bag compression stuffsack
- Cotton storage sack
- Weight: 475g/16.7oz
- RRP: £359.99
Photo credit: Rab.com.
Pros: What’s good about the Rab Mythic 200
Let’s start with the weight; 475g for a 1°C limit bag is seriously impressive. Rab have primarily managed this by using an eclectic mix of 200g 900 fill power (fp) down, superlight weight Pertex Quantum fabric and some well-thought-out design features.
The fill power is essentially how well the down lofts and therefore insulates. 900fp is very high. 200g of insulation doesn’t sound like much, but as it lofts so delightfully you’ll be forgiven for thinking there’s a heck more down in the bag.
Now onto the Pertex Quantam fabric. It feels incredibly thin and silky, but also relatively tough with a mini ripstop pattern. I’ve yet to damage it, but of course it is a speciality light weight fabric, and rolling around like a bug in a rug on abrasive rocks probably wouldn’t be the best idea.
Crucially the fabric seems to breathe really well, a rather key attribute in a sleeping bag.
To save weight a ¼ length zip has been used in lieu of the classic full length. This works well to dump a bit of heat when it warms up and there are nice touches like a well-padded zip protector.
In this weight class, you’ll often see the cheaper and lighter sewn-through construction to separate the ‘down chambers’. Thankfully Rab has used a more thermally efficient baffle design which reduces cold spots.
Now, what’s interesting is that they’ve clearly introduced this without a discernible weight penalty. Props to the design team.
Enough with all the technical stuff, so actually how warm is it? Well warmth is of course subjective and for the record I do run quite hot when I sleep. Only wearing shorts and a thin thermal t-shirt, I was personally very comfortable sleeping in temperatures between 1ºC and 10ºC at night.
Furthermore, by combining with my mid weight down jacket, I happily used it in temperatures around -4ºC.
A traditional major negative of down insulation is shoddy performance when wet. Be this through direct rain, damp conditions or excessive body sweat! Rab have attempted to mitigate this somewhat by using Nixwax Hydrophobic treated down.
I had a hard time measuring their claims of drying 3 times faster and absorbing 90% less water than non-treated down; however, I used it in some reasonably damp conditions and it performed flawlessly. Unless I knew the bag was likely to get soaking wet, I’d be comfortable taking this on the majority of moderately moist outings.
I’m 6ft/183cm with wide shoulders but a slim build and I’ve found the fit very comfortable. I don’t particularly like constrictive sleeping bags as they make me feel a tad claustrophobic, but the Mythic 200 has a generous enough cut to prevent this.
Interestingly the foot box is pre angled, which is a nice touch and makes the fit feel all the better.
Included is a cotton bag for storing the sleeping bag uncompressed when not in use (this is important for down). Now instead of a normal compression sack, they’ve provided a lightweight proper roll top dry bag. A great addition, as the last thing you want is your bag getting wet before you even try and sleep in it.
Relative to its warmth, it compresses down really well. See the comparison photo with a one litre Nalgene bottle for scale.
Price wise, the Mythic 200 isn’t cheap, but good sleeping bags seldom are. When looking at the specification, it comes in at similar and sometimes lower price point to its peers. So in relative terms, it would appear reasonably good value for money.
Cons: What’s not so good about the Rab Mythic 200
Pertex Quantum 7 fabric has a slightly clingy feel when next to bare skin. Perhaps due to its incredibly thin construction. That said, this was only a problem for me when I was hot and in colder temperatures it wasn’t an issue at all.
Not so much a con as a design compromise, the ¼ length zip works great in colder conditions, but a full length zip certainly has its uses when temperatures rise. I’d personally take the slight weight hit of a longer zip for the increased versatility.
Rab started out making sleeping bags nearly 40 years ago and their heritage really shows, not just in the high quality construction, but in how the design elements come together to produce a sleeping bag that marries class-leading specs with nearly flawless real-world usability.
For me, as someone who sleeps on the hot side, the lack of a full length zipper means that I’d ideally use a quilt or even lighter sleeping bag in warm night time conditions. But for nearly every other kind of summer outdoor sleeping scenario, this currently seems to be one of, if not the best, options on the market.
Other sleeping bags you may want to consider:
Mountain Hardwear Ghost Whisperer – £399.99
Sea To Summit Spark SpII – £349.99
Haglofs Lim Down – £339.99
All images Luke Jarmey except when stated.
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