Review – Rab Neutrino 400 down sleeping bag

Neutrino 400 at rest with the invisible man

“Rab certainly are churning out some fantastic products in recent months and the Neutrino 400 down sleeping bag is no exception. It’s feature packed, with some of the best performing down I’ve come across in years and light, too. For 3 season use – which is most of the year, really – I think you’d struggle to find as good equivalent. It’s fantastic value for money for such a versatile, high quality product and worth every penny.”

So, spring has sprung and the summer season is all but upon us and in next to no time we’ll be marching into autumn – scary, eh? Funny how when you’re a kid days feel like weeks, and months like years – yet as we get older in life time flies at ever greater speeds. Depressing really…

Silky smooth and very comfortable with lots of features

Anyway, this talk of time and seasons is a point for consideration – especially when it comes to purchasing a sleeping bag. Temperatures in the UK can vary wildly from April to October when you’re out hiking and camping. You could encounter cold nights with an early morning frost one minute and the next a warm and balmy evening where every inch of your body is pouring with sweat – gross but true.

As most readers will be well aware, down still gives the best warmth to weight ratio for insulation. Though you have to ensure the feathers do not get too damp or wet through (as this negates any insulating properties down has) it also has the added benefit of having a wider range of comfort temperatures than synthetics.

Furthermore, down drapes or settles over the user much better than any man made fill – thus eliminating any potential cold spots.

However, the effectiveness of any insulating materials is effected by how humid the conditions are (you can feel cold in a sleeping bag if you’re damp with sweat, for example) and even the body of air which surrounds the user can effect heat retention.

These are all factors worth noting due to the nature of the UK’s climate running from April to October – that period many manufacturers call “2-3 season”.

Sounds quite a minefield, eh? And it is really.

The giant orange slug leaps out it’s fully taped and double-lipped dry sac

Some of the lightest sleeping bags available omit features such as zips and even draw cord hoods – things you may wish to use given all of the above just for versatility. Of course, some folk (including myself) may not find this too much of a distraction as we may put on extra layers of clothing if it’s a tad too cold or strip off more layers and so on.

Needless to say, this isn’t everyones cup of tea – which leads me to Rab’s Neutrino 400 down sleeping bag.

A fully featured sleeping bag which includes a hood, insulating collar, internal zip pocket, 3/4 length 2 way YKK zip with anti-snagging tape, 800 US fill power european down, a comfort limit rating to -4c  and the wonderfully silky and light Pertex Quantum outer/inner fabric – all for around 800 grammes!

First of all, lets look at the weight – well, by my now defunct scales (waiting for a new one in post) I gauged an average weight of 832g’s for the sleeping bag on it’s own. The weight varied namely due to moisture, ie my sweaty body and so on. I was trying to work out it’s ‘real world’ weight you see. Even so, it’s not a figure to scoff at either.

Large cotton storage sack comes as standard

The sleeping bag does come with a fantastic double-lipped waterproof dry sac which ups the weight by another 72 grammes or so – but as some of you will know, I dispense with such things and store my bedding in a large dry sac along with clothing into my rucksack. I just find stuffing such kit in loose like this fills out every nook and cranny of my pack more and thus freeing up more space for other bits and bobs – such as my video camera equipment.

Rab use some of the best grade down available – the loft is exceptional – and as a consequence of this 90/10 down to feather ratio it packs down extremely small and makes for a bloody light sleeping bag.

I’ve encountered many a humid night in recent weeks, along with some cold nights in late winter and consequently had to deal with a potentially damp down bag in the mornings. It’s not always practical for me to lay the sleeping bag out flat displaying it’s grey inner to help dry it out – and so I’ve had to ‘make do’ and pack. Come the following evening (more so after a few nights) you do notice the loft isn’t as good as it once was – but left be, it soon dries out and returns to normal.

Once home, the sleep bag is laid out in a dry room and left to air for at least 24 hours – and it’s this regular cycle of use that has lead me to be amazed at the quality of the down Rab are using in their products at the moment.

Normally after some time I’d expect the quality of the down to have diminished somewhat – but it hasn’t. Well, not that I have noticed. With other down sleeping bags I’ve used – cheap and expensive – you notice these signs of ‘wear and tear’ at some point. Granted, I’m out and about most days of the week – even so the Rab Neutrino 400 in this respect has performed exceptionally well. In fact, I’ve only ever come across one other brand where it’s down products just take knock after knock after knock – Cumulus. Admittedly, I’ve heard good things about Western Mountaineering but I’m yet to try any of their gear.

But compared to many other brands – large and small – the quality of the down Rab are currently using is up their with the best for sure.

Of course, the silky and extremely light Pertex Quantum fabric which makes up the inner and outer shell of the sleeping bag all contributes to the performance of the Neutrino 400. Highly water-resistant, it breathes extremely well (in effect helping to expel any moisture within the sleeping bag and not lead to condensation and damp issues within the down insulation) and feels great on the skin. Furthermore, when it comes to stuffing the sleeping bag away – any air is soon squeezed out. A mark of how breathable the fabric is and how quick you can pack up and go.

I’ve only encountered a few feathers leaking – but this is to be expected and were always along the seams. So, the fabric is certainly down proof. Once out the bag and thrown into your tent the down soon lofts to it’s max and drapes over you like a dream – in a word, brilliant.

At home out on the moors of the south western Peak District

The YKK 2 way 3/4 length zip works as it’s supposed to – ie, it’s robust and water resistant. However, I still cannot understand why Rab persist in saying it’s a 3/4 length zip. It practically runs the full length of the sleeping bag. If it lived up to it’s description then I’d expect it to finish around my knee area and not my ankles. A potential weight saving for Rab to consider – but a feature some may find as a blessing for ventilation. You could consequently use the sleeping bag as a quilt on real warm nights, for example.

The anti snagging tape works OK – I still found the zip to catch onto the inner fabric from time to time – but it’s no worst than some other sleeping bags I’ve used in the past.

The hood is roomy and shuts up extremely well when you pull on a draw cord – of which is conveniently placed for when you’re reaching around in the dark. Also, the collar sits and nestles in just the right place, too – and again pulling on a cord seals this shut and snug around your neck.

The internal zipped pocket isn’t large but it’s not too small either – you can bang a phone, keys and other small items in there OK. Though I found the zip to be somewhat tricky to open on the odd occasion.

Trapezoidal baffles – nothing new but worth noting

The bag is of trapezoidal construction – the down filled chambers are wider at the bottom and narrower at the top and vice versa along the bag – to help eliminate any cold spots along with internal mesh panels to prevent the down from migrating as and where it sees fit (when otherwise you could find clumps of down in one part of a tube and none in another!).

To be fair, in the summer months a straightforward box wall construction would suffice – but I suppose it’s a mark of Rab’s attention to detail in producing high quality products that they use this technology. And given you may use this sleeping bag in late winter/autumn it’s no bad thing. We all feel the cold differently for a number of reasons and I guess it’s wise to construct such a product this way. The angled footbox to keep your feet comfy and warm being an example of this.

On the whole, I’ve been extremely impressed with the Neutrino 400. It’s had a tough outing with me over the past few months – there’s no abrasion marks, stitching come undone or loss of loft. Ideal for lightweight backpacking, but not so much for bivvying or bothying – simply because the grade of Pertex used isn’t the toughest or most water resistant for particularly rough or damp conditions.

A wonderful sleeping bag for 3 season backpacking

Saying that it’s proven to be durable, and stuffed with some of the best down I’ve ever had the pleasure of wrapping myself in. And of course, I never tire of feeling Pertex Quantum against the skin while watching the down loft and loft in minutes. Aye, that sounds a bit kinky but it’s true!

I’m 5’11”, broad shouldered with a 44 inch chest – so, it’s worth noting that I find the sleeping bag comfortable to use. There’s not too much room, but not too little, either – which can be a problem with sleeping bags in general.

Rab certainly are churning out some fantastic products in recent months and the Neutrino 400 down sleeping bag is no exception. It’s feature packed, with some of the best performing down I’ve come across in years and light, too. For 3 season use – which is most of the year, really – I think you’d struggle to find as good equivalent. It’s fantastic value for money for such a versatile, high quality product and worth every penny.

For more information on how Rab construct their sleeping bags take a look here.


9 Comments Add yours

  1. looks like my new bag I haven't bought yet but will have to save my coins up


  2. bsdowling says:

    Nice review mate.


  3. bsdowling says:

    I have been looking for a lightweight summer bag, this is just a little heavy for me though. I do love rab bags and I have the alpine 600 partly due to your previous reviews.


  4. terrybnd says:

    @Paul – It is a mighty fine sleeping bag for what you get, for sure. And definitely worth saving up for.

    @bsdowling – Thanks. It's not that heavy a sleeping bag LOL It is a 3 season one don't forget so it covers a lot of bases, really.


  5. GeoffC says:

    I was wondering recently how long the down itself should last – would you expect its performance to decrease with use?. Our ME Lightlines are, er, 17 years old…


  6. swanscot says:

    We have Rab Quantums (600? or something?) – about 5 years old – and have been happy with them when camping in cold, damp and dry cold conditions. I love that they drape around the body and feel so soft.

    To GeoffC: our previous down bags were 25 years old before we replaced them!


  7. terrybnd says:

    @GeoffC – Down does degrade in time, defo. I got 4 sleep bags that had it after 3 years regular use. One an Alpkit one. You get different grades of down and needless to say the top end stuff will last longer if cared for. Compression and damp etc etc all effect it's shelf life.

    So, the point I was making in the review was how even after prolific use in damp conditions, packing and using again the next day – the down wasn't affected compared to other sleeping bags and their relative down I've used in the past you see.

    @swanscot – There's not many companies that use top grade down in their gear for all their products. Rab's one. Cumulus, phdesigns are another two. Some companies will use the top grade in their more expensive bags and lesser as price drops (even though it's still expensive).

    Then of course, there's the feather down ratio some will play around with and of course where the down is sourced, too.

    China being one well known and popular source – ethically how they process/source the down is open to much debate – never mind the quality of it. But it's cheap…, you can fill in the rest 😉


  8. James says:

    Thanks for another great review, I've been looking at buying a new 3 season sleeping bag and this is a great help.

    I'm currently looking at getting either a Rab Alpine 400 or this Rab Neutrino 400. Both come in at roughly similar prices, thoug the Alpine is obviously a bit heavier and warmer.

    I wondered if you had any advice which could help me differentiate between the two?

    I use a Vaude Power Lizard tent and have had some issues with venting/condensation which might lead me to the Alpine, but then for 3-season use in the UK (Lake District and occasionally Scotland) I wonder if it might be just that bit too warm and un-breathable (suffocate-able?).

    I can't really see the wood for the trees anymore so any advice you might have would be greatly appreciated. Thanks again for the review.



  9. terrybnd says:

    Hi James,

    In all honesty, either is fine. In which case go for the Neutrino. It's shell is more than capable of shedding any condensation etc.

    Furthermore, the shell on the Neutrino is more breathable than the Alpine which is a bonus for quick drying/airing.

    If it does worry you so, then go for the Alpine which is the tougher of the two sleeping bags, if you like.

    Either way, care and common sense never harmed a backpacker 🙂


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s