Are all 900 down bags the same?

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Sub5mango

Tenderfoot
Oct 13, 2019
92
12
55
East Anglia
Based on materials and construction (not rating), is there any reason that one of these 3 sleeping bags should be warmer than the others?
1. Alpkit 900
2. Rab 900
3. OEX 900
 

brambles

Settler
Apr 26, 2012
771
71
Aberdeenshire
Ignore the extreme temp rating for the OEX , it is fictional. I bought one and immediately returned it because it was nowhere near the advertised size in width across the shoulder.
 
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baggins

Full Member
Apr 20, 2005
1,563
300
49
Coventry (and surveying trees uk wide)
Look at the fill power. That is the amount of space that 1grm of down will fill (in cm3). So, the higher the fill power, the higher the quality the down.
Of the 3 bags the OP mentioned above, the Rab and the Alpkit have the higher fill power at 650 opposed to 600 for the OEX. In contrast, i have a good quality winter down bag at 900 fill power (but it was alot more money). The higher quality down that is used, the warmer the bag should be.
Saying that, shape will play a part, but that is a very personal thing. i, for instance, like quite a roomy bag, so i can move about inside. I feel colder if i feel hemmed in.
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
6,154
1,546
Cumbria
I'd expect the Rab would be best quality then the Alpkit one. Probably my prejudice though.

A few points to note. All have 900g/M2 of down but one has a lower fill power. This should signify a colder bag. Also the lightest bag is the one with lowest fill power and iirc cheapest. If these are considered equivalently performing bags then something is not ringing true with the leviathan bag from go outdoors own brand OEX. If something seems dodgy I'd avoid.

The other two have same fill power and weight of infill. They seem equivalent. The Rab one has hydrophobic down ( like the cheapo one I'd rule out), the Alpkit doesn't. Alpkit do use hydrophobic down with some of their bags so I'm not sure why not in this one.

Other than this the quality of design will mark the difference. I'm surprised the Rab is the heaviest bag though.

My view is Rab and Alpkit bags are worth looking at but the other isn't.
 
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BigMonster

Full Member
Sep 6, 2011
1,322
219
Manchester
It's all about the quality (fill power) of the down used. To be hones the Ascent line of RAB bags is average and almost equals top of the range synthetic (for example Mountain hardware Lamina line).
If you wan't to invest in down bags:
1. It only make sense for low temperatures below 0C. Otherwise you are only saving 100-200 grams for a lot of hassle and money.
2. Only buy good/best quality to actually get the benefit of the down which are weight and volume saving (for a steep price and higher hassle factor).
3. Make sure you really need one. For the price of one decent quality down bag you can have 2-3 top quality synthetics which can be used in anger and will take care of themselves.

Down is fancy but apart from a winter overnight on top of BenNevis I can't see a use for down bag in UK. I have been there, down top quilts and RAB bags. Sold everything on ebay and couldn't be happier with my MH Lamina synthetic bag for a fraction of price that I'm not afraid to smoke by the fire or hanf to dry after coming back from the trip. Oh, washed it many times in a washing machine, never was brave enough to do that with my RAB down which resulted in £35 profesional wash...
 

Sub5mango

Tenderfoot
Oct 13, 2019
92
12
55
East Anglia
It's all about the quality (fill power) of the down used. To be hones the Ascent line of RAB bags is average and almost equals top of the range synthetic (for example Mountain hardware Lamina line).
If you wan't to invest in down bags:
1. It only make sense for low temperatures below 0C. Otherwise you are only saving 100-200 grams for a lot of hassle and money.
2. Only buy good/best quality to actually get the benefit of the down which are weight and volume saving (for a steep price and higher hassle factor).
3. Make sure you really need one. For the price of one decent quality down bag you can have 2-3 top quality synthetics which can be used in anger and will take care of themselves.

Down is fancy but apart from a winter overnight on top of BenNevis I can't see a use for down bag in UK. I have been there, down top quilts and RAB bags. Sold everything on ebay and couldn't be happier wit MH Lamina synthetic bag for a fraction of price that I'm not afraid to smoke by the fire or hanf to dry after coming back from the trip. Oh, washed it many times in a washing machine, never was brave enough to do that with my RAB down which resulted in £35 profesional wash...
Thanks. I have a synthetic, snugpak tactical 3, and I get cold in it at +2c, despite it being rated at -7c comfort level. (tactical 3 is 1.7kg, packed 23cm x 20cm). So I was looking at down because I don't want to increase size or weight, preferably reduce. The rab 900 is approx 1.5kg and 24x45 cm packed, rated to -11. So it is a big size jump, but a slight weight drop. (At -3 I got cold in the oex rated at -9). I just looked at the laminas . Interesting. Lamina -18c seems overkill, and has weight of 1.9kg, pack size 24x46cm. Lamina -9c, 1.4kg, 20x42cm, seems a bit low rating for my needs considering I'm cold in the tactical 3. Which do you have and are you a cold sleeper? Also how roomy is the lamina compared to the rabs you had? I like a roomy fit if possible. (The tactical 3 is a bit tight on the hips).
 

Paul_B

Bushcrafter through and through
Jul 14, 2008
6,154
1,546
Cumbria
Down isn't as fragile as people make out at times IMHO. I've had my down swimming in water before now. We decamped to a hostel and I'd dried it out and was using it that very night. It wasn't harmed in any way and lost no warmth. We've washed ours too and a simple tumble dry with a tennis ball really made it perform again.

Price is more for down but I've bought when I've seen something suitable at a great price. £100 for a golite quilt using 900 fill power down. It was in xl size too which I do need for my height. Anyway 690g actual weight and I've been below zero a few times without ever feeling anything but snug. Pack size less than 3/4, of a Nalgene flask. I've bought a marmot Fusion sleeping bag in xl for £110. That's rated about zero and has down inner at iirc 800 FP and primaloft original to the outer layer. Packs to a Nalgene and a half I reckon.

Basically it's really a choice. With sensible precautions down offers better pack size, weight and temperature range. Synthetic is heavy, bulky and IME loses temperature performance with age.

Btw when you're camping in your synthetic bags do you usually allow your bags to get wet, I mean so wet that a down bag truly becomes unusable without a tumble dryer and balls? If it's that wet how do you dry it out to use it the next day?

I'm totally biased towards down. I've never had an issue with water and I've used the same quilt camping at 15+°C down to -7°C. IMHO synthetic wouldn't have been comfortable in that range. Plus it's allowed me to fit my backpacking kit into a 4kg load including food for three days and a 25 litre capacity sack. Previous synthetic bags I've owned would have filled that sack up.

I agree with the Rab bag being the lower spec bag at that rating in their down range. I'd try and get a better one from Rab if money allows or the Alpkit one. Possibly wait for sales. Keep an eye on outdoor forum bargain pages. I saw my quilt at 2/3rds off RRP through a forum. There were 15 for sale on that Thursday I got the last one Friday afternoon.
 
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Sub5mango

Tenderfoot
Oct 13, 2019
92
12
55
East Anglia
Down isn't as fragile as people make out at times IMHO. I've had my down swimming in water before now. We decamped to a hostel and I'd dried it out and was using it that very night. It wasn't harmed in any way and lost no warmth. We've washed ours too and a simple tumble dry with a tennis ball really made it perform again.

Price is more for down but I've bought when I've seen something suitable at a great price. £100 for a golite quilt using 900 fill power down. It was in xl size too which I do need for my height. Anyway 690g actual weight and I've been below zero a few times without ever feeling anything but snug. Pack size less than 3/4, of a Nalgene flask. I've bought a marmot Fusion sleeping bag in xl for £110. That's rated about zero and has down inner at iirc 800 FP and primaloft original to the outer layer. Packs to a Nalgene and a half I reckon.

Basically it's really a choice. With sensible precautions down offers better pack size, weight and temperature range. Synthetic is heavy, bulky and IME loses temperature performance with age.

Btw when you're camping in your synthetic bags do you usually allow your bags to get wet, I mean so wet that a down bag truly becomes unusable without a tumble dryer and balls? If it's that wet how do you dry it out to use it the next day?

I'm totally biased towards down. I've never had an issue with water and I've used the same quilt camping at 15+°C down to -7°C. IMHO synthetic wouldn't have been comfortable in that range. Plus it's allowed me to fit my backpacking kit into a 4kg load including food for three days and a 25 litre capacity sack. Previous synthetic bags I've owned would have filled that sack up.

I agree with the Rab bag being the lower spec bag at that rating in their down range. I'd try and get a better one from Rab if money allows or the Alpkit one. Possibly wait for sales. Keep an eye on outdoor forum bargain pages. I saw my quilt at 2/3rds off RRP through a forum. There were 15 for sale on that Thursday I got the last one Friday afternoon.
Thanks. Why get the alpkit over the rab ascent 900? Although the ascent 900 is low spec relative to the others in rabs range, isn't it still better spec than the alpkit which doesn't have hydro down?
 

BigMonster

Full Member
Sep 6, 2011
1,322
219
Manchester
Fit and comfort wise best thing would be to try one in the shop, not possible right now really. As for the temp rating I prefer to have some safety margin for when I am wet and tired and can't get up to temperature easily for the night. Only experience will tell you what you need.
I agree with Paul B. Down doesn't burst in flames at first sight of moisture, terrible myth created by sales people. Don't get sucked in to the hydrophobic down hype (create a problem and then let them pay for solution), down is naturally hydrophobic already. The artificial stuff will last a bit longer when submerged, which is irrelevant.
Had my bags damp many times without drama. But with synthetic you don't have to dry it out asap and you don't have to worry if it rains for 5 days straight with no chance of airing your bag. Synthetic is simply less maintenance and less stress if it gets dirty, damp or the outer fabric gets a nick or tear.

You have to balance high performance kit vs convenience.
 

BigMonster

Full Member
Sep 6, 2011
1,322
219
Manchester
Good comparison of natural down vs artificially hydrophobic down:

Yes, down will smell and eventually rot if you leave it wet. But they have created a myth that down bag is useless when wet. As you can see natural down is perfectly adequate for a sleeping bag. If I was buying a down sleeping bag I would rather pay for better fill down than for hydrophobic treatment.

Don't obsess over it. It's really irrelevant and people have been using "ordinary" down for the last 100 years.
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
6,154
1,546
Cumbria
The down in the Alpkit one doesn't say hydrophobic down but last year they sold off a load of 2018 spec bags without hydrophobic down because they had switched to this better down. That was the pipedream, quilt and other ranges. That makes me wonder if the write-up on the site hasn't been updated for this product and it does have hydrophobic down. Might be worth contacting them to clarify perhaps.

Whatever the truth there's still many very good brands with normal down in their sleeping bags. Many people cope perfectly well with normal down. I'm in also sure people can get complacent with hydrophobic down. It's not waterproof and water still causes it to clump if it's truly wet. When the foot of your tent has water up to the mesh panel in the morning no sleeping bag will keep your feet warm! I've been there. Complete with floating boots outside the inner tent!!

I'd choose Alpkit but there's really little in it. If you can find out pack size.. if one is a lot bigger then I'd go with the other. The weight difference isn't too great IMHO.

One more plus for down. My quilt was bought a year after my marmot fusion which has down inner and primaloft outer insulation. Both well treated with storage in the dry and in the supplied mesh storage bags. The quilt got more use. Now I'm using the fusion bag more for car camping. It's very tired but the quilt is good as new. Reason? The primaloft is failing and you can feel gaps in it. The down quilt shakes out and is good as new. The fusion had a sub zero comfort rating but I now need my primaloft gilet and even jacket on when just about zero.
 

Old Bones

Settler
Oct 14, 2009
745
72
East Anglia
Thanks. I have a synthetic, snugpak tactical 3, and I get cold in it at +2c, despite it being rated at -7c comfort level. (tactical 3 is 1.7kg, packed 23cm x 20cm). So I was looking at down because I don't want to increase size or weight, preferably reduce.

I bought a Snugpak Osprey 12 back in the nineties, and it was never as warm as advertised - and a look around the internet shows that Snugpaks are notorious for their temp ratings. And certainly no longer cutting edge.
I let my son use it last year for a school camp. Its lost a fair amount of loft (to be fair its decades old), but it still took him and a teacher to get the bag back in the bag, and they did not entirely succeed - thats the problem with synthetic bags - they tend to be relatively bulky. My ME down bag is way easier to pack

As for the three, the OEX has a lower fill , so yeah, its going to be less efficient than the other two, and that temp rating looks a bit suspect. There is a really good overview about fill power and loads of other stuff about down on the PHD website (OK, so thats looking at Savile Row, but we can all dream). But fill power and percentage of down does make a difference, and that costs.

As for the other two, as others have pointed out, the bags, are the same weight of fill, with the same fill power, so are probably pretty similar. But its a bit like having the choice of two suits, pair of shoes or TV's - it comes down to fit.

I remember a comment a couple of years back that thought the Alpkit was great value, but perhaps a little on the narrow side. Rabs are easier, because pretty much every Go Outdoors and most other decent outdoor shops should have at least one of their bags, most likely the 900. OK, thats going to be out of bounds for the next couple of months, but your not buying a pig in a poke. I am a big Alpkit fan, but like clothing, bags are something that I like to try on. I tried on a Mountain Hardware Lamina in Cotswolds a couple of years ago - great bag but personally, I found the foot tight. Its very individual.

Both have a good reputation, but big brand down manufacturers tend to be a bit cautious with regard to the 'offical' test figure, and will often have a 'good nights sleep' figure which might be a bit lower, because of their experience, etc. So I would probably chose the Rab, but there might be a really good Alpkit deal. If your close enough, you can go to one of their stores our their HQ outlet. At least at some point....

Roughly £199 to £219 (assuming you go for the 15% discount at Go Outdoors) is good value for a roughtly minus 12-13 bag which comes in about 1.5kg. But if your willing to spend a little bit more (and looking at retailing at the moment, I suspect deals will be ramping up as stores try to tempt us in order to move stock), I would throw another one into the mix - a Mountain Equipment Classic 750.

This bag comes in at 1.33kg, with a fill weight of 718g. But the fill power is higher, at 700, at a minimum. My ME Lifeline jacket's swing tag said that its fill power was actually 725, although its officially 700. And while the Rab is using 80/20 fill, they are using 90/10. So its a bit lighter and a bit less bulky, but its official comfort level is minus 12 (and ME reckons a good night sleep at minus 14), pretty much the same as the other two. Trekkit have it at £225 at the moment with free delivery. The ME Classic range (I have the 500) is essentially their equivalent of the Rab Asecent range - entry down bags, but solidly decent with a good brand name.

Good luck - bags are one of those subjects everyone has an opinion on, and until you have bought it and used it, your not sure if its does what you think it will. Which is potentially a lot of money that might go to waste. But the RAB, Alpkit and ME are all solid bags
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
6,154
1,546
Cumbria
Different bags different features even before you consider insulation type. Seems you were
more motivated by size and zip location. Not many XL centre zip sleeping bags using down I reckon.

Size isn't an issue because there's enough very good brands with XL versions of popular down bags. All my bags are XL for the length I need.. I personally wouldn't go to synth just for bag size. Centre zip? Never understood that design, for me side zip seems more sensible but that's choice of course.

Whatever bag you use that's your choice. You do your research then make your choice. I don't think my choices of bags will suit the OP as well as what he ends up choosing. All I offer is my view, knowledge, experience and results of all.

I also looked up Andy Kirkpatrick website and his comments on down Vs synth. It was from something like 2008 but still relevant because it mentioned the newer synthetic fibres out. He categorised bags for use in a climbing application. The more technical your accommodation the more likely down was recommended. Synthetic was basically dossing at hostels, friends or car based camping. It also sounded like he thought they were more for budget end of market. He's an experienced mountaineer and is known for his knowledge on gear and clothing for outdoor use.
 
Jan 13, 2018
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Rural Lincolnshire
Down isn't as fragile as people make out at times IMHO. I've had my down swimming in water before now. We decamped to a hostel and I'd dried it out and was using it that very night. It wasn't harmed in any way and lost no warmth. We've washed ours too and a simple tumble dry with a tennis ball really made it perform again.


Q Where does down come from ?
A The chest of Ducks

Q What is the 'natural environment' for Ducks ?
A On the water.

Ducks don't seem to have any major problem with water, some simple 'taking care' of your down-bag is all it takes.
Don't use it as a boat or go swimming in it & let it 'air out' when you have had a hot-&-sweaty night and it'll last for years.
If it does get wet, dry in a tumble on a low setting with a couple of tennis balls to roll about and keep it 'fluffed up'.
 
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Paul_B

Bushcrafter through and through
Jul 14, 2008
6,154
1,546
Cumbria
That quoted post was in response to someone, and I think this is a correct paraphrasing, saying that synthetic bags are more durable and better because you'd don't have to take as much care as you do with down. I've had wet tent nights in synthetic and down. However I once had to dry down bag on a hostel radiator or go home. The hostel attached to a pub won out. My bag was useable by night time.
 

Old Bones

Settler
Oct 14, 2009
745
72
East Anglia
and I think this is a correct paraphrasing, saying that synthetic bags are more durable and better because you'd don't have to take as much care as you do with down. I've had wet tent nights in synthetic and down. However I once had to dry down bag on a hostel radiator or go home. The hostel attached to a pub won out. My bag was useable by night time.

One of the big problems about the descriptions of down vs synthetic on the net is the binary way they are often expressed. Down is often essentially described as turning to porridge should it come into contact with any moisture, which is evidently untrue. The reality is much more nuanced, because DWR has nullied some of the problems with down, the net had flattened the pricing a bit, and synthetics have also got a bit less bulky (Mountain Hardware's Lamina, for instance).

But some people will tend to buy synthetics on the basis of what they have read (rather than the advantages they do actually posses), and then get very defensive about their purchase, and repeat the same points. And so it goes on.

I was promised by Snugpak back in 1994 that their synthetic fill was almost as good as down. Like my jet pack, I am still waiting, although quality brands are evidently confident enough about synthetic insulation to use it in their high level jackets, but its telling that the bulk of their bags are still down.
 
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