UKC Forums - Are Sleeping Bags with expensive down worth it?

Are Sleeping Bags with expensive down worth it?

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m0unt41n 27 Dec 2010

I understand the difference between USA and European measures of Down.

But what does seem odd is that you can buy the same Sleeping Bag with either 700 fill, 800 or 900 fill down (European measure).

Surely a bag is designed so that its volume, between inner and outer material, is suitable for a specific fill. If you use a higher lofting down then it can’t loft properly or a lower one and there will be empty spaces.

Also there doesn’t seem much point in paying for a high lofting down in the bottom of the bag since you swash it. So there is unlikely to be much difference in warmth between a bag with 600 or 900 down in the bottom.

So the only difference in terms of warmth can be due to the down in the top and the bag construction.

I guess its impossible to answer unless you buy a bag with 700 fill and another one the same with 900 fill and use both in the same circumstances.

There is a big difference in price and I wondered if it was really worth it?

mikehike 27 Dec 2010

In reply to m0unt41n:

Interesting point.
We need someone in the know who works for an OEM and tests bags.

I believe down is also graded on its ability to unfurl after compression.

Also I think you can split bags into two catagories.
1)Bleeding edge lightweight type that compress small eg Cumulus Quantum range,
designed for backpackers.
2)Then you also have expedition type (which i have no experience).

I think its the former that would be most applicable to your above point.

Of backpacker type bags,I guess, the labour cost, shell material & fill material could be split into unequal 3rds of say 50/30/20% respectively for bleading edge bags made in the uk. Where as budget bags made in china may be 33/33/33%. Thus the labour and shell materials push the price of quality bags up. Not actualy the down.

Just my thoughts and not backed by any actual knowledge.

mh

WhenImReady 27 Dec 2010

In reply to m0unt41n:
In short; yes.
Buy the best quality down bag you can, and you'll get the use out of it.
My enlightened Dad bought me a Rab down bag in 1986 and I'm still using it as my best winter bag, despite many years hard use. - It's been back to Rab and been re-shelled and the down weight brought back up, but this cost a fraction of the cost of a new one.
I've had other cheaper bags in that time; they always bleed down/feathers and give up the ghost.
Save the cash, go for Rab or PHDesigns bag and lie back in comfort!

gethin_allen 27 Dec 2010

In reply to m0unt41n:
I've heard in various places that 900 fill down is a bit of a waste of cash as the sleeping bag material squashes that little bit extra loft out of it so getting a 700 is plenty good enough for the average punter.

Mr Lopez 27 Dec 2010

In reply to m0unt41n:

> I understand the difference between USA and European measures of Down.
>
> But what does seem odd is that you can buy the same Sleeping Bag with either 700 fill, 800 or 900 fill down (European measure).
>
> Surely a bag is designed so that its volume, between inner and outer material, is suitable for a specific fill. If you use a higher lofting down then it can’t loft properly or a lower one and there will be empty spaces.

Cutting through the sales crap, the practical difference between different loft down is the weight of the down itself. Simples.

So 2 bags with the same volume of down will have the same rating, but the one with 900fill down will be considerably lighter than one with 600fill.

To put it another way, a bag with 600fill will have (i.e.) 800g of down, and the one with 900fill will have 550g of down.

> Also there doesn’t seem much point in paying for a high lofting down in the bottom of the bag since you swash it. So there is unlikely to be much difference in warmth between a bag with 600 or 900 down in the bottom.

> So the only difference in terms of warmth can be due to the down in the top and the bag construction.

Many brands use different amount of insulation in the top and bottom for that very reason, with some bags doing away with the bottom insulation altogether. Problem here, is that in a bag you are likely to roll, and end up with the less insulated section exposed.

> I guess its impossible to answer unless you buy a bag with 700 fill and another one the same with 900 fill and use both in the same circumstances.

As said above, both bags will perform the same, but will weight different.

> There is a big difference in price and I wondered if it was really worth it?

It depends how important the weight is for you. I got a bag that kept me warm at -30, has a waterproof outer, and weights 1.2kgs!!!

Obviously not everyone needs something like this, so you have to think on what your needs are.

ice.solo 29 Dec 2010

In reply to m0unt41n:

can someone send a link to a 900 (european) fill bag.

and maybe another link to anyone who can afford one

the difference is noticeable at altitude - the ratio for carrying loft:weight matters when every 100m gets harder and colder.
being a fan of the z-rest i like down under me. its still compressed of course, but not as much as with other systems, and you get the layer of foam as well.

my thoughts for an effective system is a nice 650/700 fill bag with an even nicer pair of 800/900 fill pants, booties and belay jacket.
the insulation of the 2 down bits plus the air between layers works well.
a case of the whole being greater than the sum of the parts.

Yanis Nayu 29 Dec 2010

In reply to WhenImReady:

> (In reply to m0unt41n)

and I'm still using it as my best winter bag, despite many years hard use. - It's been back to Rab and been re-shelled and the down weight brought back up

You are Trigger and I claim my £5!

nufkin 29 Dec 2010

In reply to ice.solo:

> (In reply to m0unt41n)
>
> can someone send a link to a 900 (european) fill bag.

http://www.phdesigns.co.uk/sleepingbags.php?cat=92

Not used one, but they look exceeding luverly

m0unt41n 29 Dec 2010

In reply to nufkin: Which was really my query, using the the PHD design your own
A bag with
750gm of 800 power down gives same temp rating (-24C) as
650gm of 900 power down
the bag with 800 power down costs £64 less and weighs 120gm more.

Which doesnt make sense since it should weigh 100gm more because of the extra down, BUT both must loft the same to produce the same temp rating so there should not be any need for extra material.

Which is where I started from. As if when you choose to upgrade the down from 800 to 900 exactly the same bag is used, in which case there should not be extra room for the extra loft of the 900 down.

This shows up in that the weighs of the bags are always exactly the same for the same weight of down but of different power. Whereas a bag with higher power down should weigh more because the outer skin should be a bit bigger to accomodate the extra loft.

Which suggests that there is no point paying the extra for upgrading the down.

TeeBee 29 Dec 2010

In reply to m0unt41n:

> (In reply to nufkin) Which was really my query, using the the PHD design your own
> A bag with
> 750gm of 800 power down gives same temp rating (-24C) as
> 650gm of 900 power down
> the bag with 800 power down costs £64 less and weighs 120gm more.
>
> Which doesnt make sense since it should weigh 100gm more because of the extra down, BUT both must loft the same to produce the same temp rating so there should not be any need for extra material.
>
> Which is where I started from. As if when you choose to upgrade the down from 800 to 900 exactly the same bag is used, in which case there should not be extra room for the extra loft of the 900 down.
>
> This shows up in that the weighs of the bags are always exactly the same for the same weight of down but of different power. Whereas a bag with higher power down should weigh more because the outer skin should be a bit bigger to accomodate the extra loft.
>
> Which suggests that there is no point paying the extra for upgrading the down.

As I understand it, equal weights of 800 and 900 power down would result in different amounts of loft (more for the 900) - thus the same degree of loft (and warmth retention?) is achieved with less down, so no need to use different shell sizes for the sleeping bags. I don't know how that would account for the extra 20g difference on top of the down weight in your example, though.
And as I think someone mentioned above, there's other advantages to higher fill powers - they'll likely compress smaller, recover better and last longer, which may help justify the extra cost a little more than just the few grams of weight saved.

m0unt41n 29 Dec 2010

In reply to TeeBee: In my example if you have the same amount of weight of 800 or 900 down the bag with 900 down should be bigger since it should loft more - but on the PHD web site the bags weight exactly the same.

I agree that if you had a bag with 650g of 900 down it should weigh exactly 100g less than the same bag with 750g of 800 down since they both must loft the same.

I am being pedantic because the numbers suggest that in the real world there is likely to be no real difference between them if exactly the same bag is used.

arty11 29 Dec 2010

In reply to m0unt41n:

It will be warmer for any given weight, as mentioned previously. It will be warmer because it will loft to the maximum whereas a lower fill power may not over time loft to the extremes as a higher fill power, hence not as warm. Basically the loft power means more resistant to compression and therefore traps more air. As for squashing it, yes you flatten where you lay, but not everyone sleeps on their back all night as you roll in your sleep etc. So if you get a higher fill power bag, it will recover loft easier/better once you move and uncompress it. Totally up to you what you do, but you WILL be warmer in a higher fill power bag... Simples!