What the manufacturers say:

The Andes series are a range of down sleeping bags filled with 800 fill power European goose down.

The Andes series bags offer comparable levels of warmth to the Expedition bags but in a more performance orientated shape. The mummy shape saves weight and adds warmth due to the lower internal volume of the bag that needs to be heated.

The Andes bags feature a water resistant outer fabric that offers extra protection and piece of mind on cold, damp belays. Ideal for use at altitude or on exposed belays when maximum warmth to weigh and small pack size are required.

Price: £560

• Pertex® Endurance outer fabric
• Pertex® Microlight inner fabric
• Pertex® Endurance inner fabric in hood and foot
• 800FP European Goose Down
• Rab® fluorocarbon free Hydrophobic Down developed in conjunction with Nikwax®
• Improved close fitting neck baffle design
• Longitudinal chest baffles with internalFlowgate® technology to control down
• Face baffle for improved hood fit
• Mummy shape
• Longitudinal foot baffles to minimise down migration
• Proportionally assigned differential cut
• Internal YKK 3 coil zipped stash pocket
• ¾ length YKK 5 coil main zip
• Left hand zip only
• Anti snag zipper webbing tape
• Internal collar and hood drawcord
• Trapezoidal baffle chamber design
• Angled foot box
• Dry bag compression stuff sack
• Cotton storage sack
• Hand filled in Derbyshire UK
•  

Weight: 1410g

Fill: FP Grey Goose

Fill Weight:800g

Length: 210cm

Shoulder Width:73cm

Foot Width:41cm

Rab Andes 800 Tested and Reveiewed - Dave Mycroft

Over the years I've found there are three essential components to a good outdoors trip; comfortable footwear, reliable shelter and a good sleeping bag. As a result I've found what works for me and I've become almost immovably brand loyal. Yes I've looked at alternatives and given them a go but when the weekend comes it's always the same trusted products that go in the pack by default. When it comes to sleeping bags I bought a Mountain Equipment Snowline 15 years ago and it was a life's dream come true. Other bags have been and gone but when the Snowline needed repacement I looked no further than the latest version of the same bag. That was until now! Put simply the Rab Andes 800 has redefined what I thought was possible in a sleeping bag.

At 1400g the Rab Andes 800 is nothing special in the weight stakes being around average for a bag of this rating, but that's the only point at which the Andes is average. The 800 FP Grey Goose down filling is, like all down used in Rab bags, hydrophobic and comes sandwiched between water resistant Pertex Endurance shell and liner fabrics meaning the age old problem of religiously protecting down bags from water has been consigned to history. The high loft of the 800 FP down means enormous amounts of air are trapped and heated and once warmed the air is held in place by close to airtight baffles. A combination of horizontal baffles in the lower section and vertical baffles in the upper body prevents down migration and the face baffle not only gives an almost hermetic seal but also gives a better overall fit for the whole hood.

The Andes 800 is a slightly narrower cut that the Mountain Equipment Snowline but it's optimised for performance with a reduced volume of air between the user and the bag itself and the result is a very warm bag. The footbox is again smaller than I'm used to but far from restrictive and the pre-set angle puts the feet in a comfortable position and it only takes a few minutes to adjust to the different proportions. In use the zip proved faultless, whether pulled slowly or suddenly and quickly it avoided snagging every time and as with the hood drawcord proved simple for single hand operation.

Where the Rab Andes really excels, however is its treatment of water and it was inevitable we'd try and "break" it. Throw a mug of water at it and the water simply bounced off, pour half a litre slowly onto it and it beaded and rolled serenly off the side. Throw it on a z-lite in the snow for a couple of hours lie-down and it emerged totally unscathed. Does it stay warm when wet? I really don't know because short of holding it underwater in the bath I'm not sure how to get the water into contact with the down and I'm not convinced that's "real world" testing. Given the performance of the Nikwax treated down Rab use, however, I'm more than confident it will retain its insulating properties.

Some may ask why spend so much on a hydrophobic down bag when there are less expensive sysnthetic alternatives and to be fair it's a very pertinent question with the recent developments of "synthetic down". The answer is quite simply that nothing compares to down in terms of loft and insulation per gram of filling. Nothing is as compressible as down without losing its ability to bounce back and loft and nothing feels quite as luxurious as down. In practical terms it means you carry less weight, have more space in your pack and get a better night sleep with down. Having found a way to remove the "water issue" the Andes 800 is like having your cake, eating it and going back for more. At £560 it's a lot of money but you can knock £100 off that for street price and what you have to remember is a quality down bag will last you a decade or more so in cost per year it's value for money. The Rab Andes 800 has the capacity to open up new worlds of winter mountaineering with its resistance to water and even when it's not pushing the limits it's as close to a guarantee of a good night's sleep as you're going to get. The only downside is a proven capacity to induce inertia when the user should be getting up to catch a sunrise!