The Rab Mythic 600 is a mummy sleeping bag filled with down and suitable for 4-season camping. Read the review or watch the video!
- Weight: 917.6 grams (Claimed 885 grams)
- Pack size: 21 x 27 cm
- Size: 215 x 70 cm
- Price: € 599.95
The Rab Mythic 600 is a mummy sleeping bag filled with down and because of its comfort temperature of -5 degrees Celsius it is suitable for camping when temperatures drop below zero. Think about cold summer nights in the mountains and to a certain extent also about winter camping.
Dimensions and weights
The Rab Mythic 600 weighs 917.6 grams on my calibrated scale and that is light. Certainly when you consider that of those 917.6 grams, 600 grams are taken up by the down filling and that the packaging of the down therefore weighs only 317.6 grams. Rab claimes a weight of 885 grams, but that difference can be explained by the more than a year of use. The sleeping bag has a length of 215 cm and at the shoulders it is 70 cm wide. In practice, this makes the Mythic 600 suitable for people up to a length of 1.85 meters. The Rab Mythic 600 is a unisex sleeping bag: suitable for men and women. And … it is only available in a version where the zipper is on the left.
Both the inside- and outside fabric of the Mythic 600 are made from Pertex Quantum 10 Denier. Pertex is a polyamide (nylon). It is very light and flexible, but also extremely durable. The 10 Denier indicates how thick or – in this case – thin the fabric is. 10 Denier is super thin. And that says nothing about the strength. After a year of intensive use, it is still without any wear and tear. The Pertex has been treated with a water-repellent coating. Condensation from sleeping in a tent and touching the fabric or sleeping outside in nice weather with a morning dew is no problem. This of course does not mean that the sleeping bag is waterproof. The material itself feels pleasant on the skin, but further on more about the comfort.
The outer and inner lining are constructed with trapezoidal baffles. These baffles – and the shape – are created in a way that they are evenly filled with down. The baffles are necessary because they prevent the down from traveling through the entire sleeping bag, so you get places with lots of down and places without down. With baffles you get an equal insulation distribution and no cold spots. An additional advantage is that a manufacturer can choose to fill some baffles a little more and others a little less. For example the baffles around the always cold feet. The baffles also ensure that the inner and outer lining never touch each other and therefore they prevent thermal cold bridges.
The Rab Mythic 600 is filled with European goose down that is RDS certified. More about the Responsible Down Standard in the link below the story. 90% of the down consists of down feathers and 10% of feathers. The 600 in the name stands for the fillweight: the 600 gram mentioned earlier. The down has undergone a treatment with Nikwax, making it water-repellent – hydrophobic. This prevents the down from getting damp due to sweat or damp weather. Down that is damp insulates less and sticks to each other resulting in even less insulation. And hydrophobic down dries faster. This water-repellent treatment is completely free of PerFluorCarbon and that is good, because these PFCs destroy our ozone layer.
The quality of the down with which the sleeping bag is filled is also important. This quality is indicated in Fill Power and is displayed in the CUIN unit. CUIN stands for Cubic Inch (per Ounce). The Rab Mythic 600 is filled with 900 CUIN down. A little more explanation is appropriate here.
Fill Power and CUIN have everything to do with the way in which the quality of the down is determined. In a test set-up, a fixed amount (1 ounce) of feathers is put in a transparent tube. There is a scale on this tube. By placing a plate (weight) on the down, the feathers are pressed together.
However, down feathers that can hold a lot of air collapse less far than feathers that are less able to hold air. You get it: far collapsing down is of a lesser quality, hardly collapsing down is a top quality. It is generally assumed that down with a Fill Power of 440 – 450 is an average quality, 500 – 550 is good, 550 – 750 is very good and everything above 750 is the absolute top. The 900 CUIN of the Mythic 600 is super.
Weight and quality
It goes without saying that the higher the quality of the down, the higher the price of the down and the end product. Why is high quality down important? The higher the insulation value, the less down you need to get a certain temperature in your sleeping bag. And although down is very light, you need a lot of down for a real winter sleeping bag of a lesser down quality. This is not only heavier but also has a larger pack volume. A true winter sleeping bag is therefore filled with a high quality down to keep you warm while the weight remains low and the pack volume small. Back to the Rab Mythic 600.
Test protocol: EN13537: 2016
Rab has subjected the Mythic 600 to the European EN13537: 2016 test protocol. This test measures the insulating capacity of sleeping bags. This enables us as a consumer to compare sleeping bags that have undergone the same test and to determine our choice. Three temperature zones are determined for this test:
The comfort temperature: the outside temperature at which a woman can sleep comfortably without waking up due to the cold. With the Mythic 600 this is -5 degrees Celsius (23 degrees Fahrenheit).
The comfort limit temperature: the outside temperature at which a man that is crawl together can sleep for 8 hours without waking up due to the cold. With the Rab Mythic 600 this is -12 degrees Celsius (10 degrees Fahrenheit).
The extreme temperature: the outside temperature at which the sleeping bag allows a woman to survive for 6 hours without getting hypothermia. However, the risk of freezing is not excluded. With the Rab this is -32 degrees Celsius (-25 degrees Fahrenheit).
Now Rab also has its own standardization: the Rab Sleep Limit. This standardization is based on the feedback that Rab receives from its athletes, ie professionals who are used to extreme circumstances. The Rab Sleep Limit for the Mythic 600 is -16 degrees Celsius (3 degrees Fahrenheit).
The Mythic 600 got a nice test during a Nordic ski trip to Northern Sweden with temperatures of -30 degrees. That was not the intention; normally the temperatures are higher there at the change from winter to spring…. But during the first night Rab’s extreme temperature turned out to be right. The nights after that I borrowed an extra sleeping bag. The rest of the year, the Mythic has proven to be warm enough for comfortable nights of about 6 degrees below zero.
A nice thing about the Mythic 600 is that it regulates the temperature very well. As long as it is not too extreme, I have rarely been too cold or too hot at temperatures between -5 and plus 10 degrees. This means you do not need a separate sleeping bag for every season. If it gets warmer: you open the zipper. One thing you have to take into account is that the Rab sometimes loses a down feather through the stitching.
The Rab Mythic 600 is very comfortable and fairly easy to use. The sleeping bag has a two-way zipper so you can unzip it from below to ventilate in warmer weather. But it is a three-quarter zipper so opening the zipper at your feet is not an option. But you can slide your feet out well if the zipper at the bottom is open.
The zipper comes from YKK. It has a small metal pull eye with a loop attached to it and a plastic pull tab on that loop. A super construction that is excellent to use with gloves or cold fingers. And … that plastic tab is a glow-in-the-dark tab. Not to be missed!
The zipper usually runs smoothly, on the inside there is a reinforcement on either side of the zipper, but you still have to use it a bit with policy; it often snags into the thin fabric of the inner lining or the draft baffle behind the zipper. This baffle does it’s job well, by the way.
The space in the Rab Mythic 600 is fine. For me as a small guy (169.5 cm) it is quite large and therefore I do not suffer from the claustrophobic feeling that you can sometimes crawl into a mummy sleeping bag. Nice is that the box around your feet is extra spacious so that you can wiggle your feet, but you can also put some clothing in it or a bottle to keep your feet warm. The hood keeps the head warm and the super thickly filled draft collar around the neck keeps warmth inside. The two can be adjusted with an elastic cord. I do miss a pocket in the sleeping bag for a smartphone, wallet or passport.
Rab Mythic 600 Stuff bag
The Rab Mythic 600 comes with a good waterproof stuff bag. The stuff bag has a roll top closure so that you can compress the sleeping bag well and make it small: a package of 210 mm in diameter and 270 mm long. Rab also supplies a storage bag with the Mythic 600 so that you can also store it in a ventilated way for a longer period of time. The sleeping bag needs little time to regain volume after it has been taken out of the stuff bag.
In the year that I was able to test the Rab Mythic 600, it has proven itself as a good all-round 4-season sleeping bag for the (high) mountains and northern regions. You can sleep comfortably up to a -6 degrees Celsius. The Pertex fabric is soft to the skin. The mummie shaped sleeping bag fits well to the body without feeling claustrophobic. If you are a bit smaller, you can definitely store extra clothing in the sleeping bag in cold weather (and this helps to isolate that space). That it occasionally loses some feathers is no big deal. You do have to be a bit careful with the zippers because they have the habit to snag. The water-repellent outer is an advantage as well as the hydrophobic down. That Rab choses RDS-certified down is good and in this high end sleeping bag it should be. The weight, the pack volume and the waterproof stuff bag are excellent. The price of € 599.95 is high, but 900 CUIN down is expensive and the price is justified. I rate the Rab Mythic 600 at 8.9 out of 10 points.
More RDS-certified Down here
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