recommend a bag

[Enzo]

Impressive bags, the space blanket tec presumably aluminized shell fabric? Presumably they found a way to do that and keep the air permibility.
I made bags using rsbtr's old 7d fabric. Have held up fine, wish I'd bought more before they stopped doing it.

The American quilts from memory tended to use 350g of down and were self rated at 20f/-6c. Optimistic perhaps.

I seem to be the biggest variable, one night 300g is good to -3, next I'm cold at 7c with the same bag.

 

[Alf Outdoors]

Not read the whole thread, apologies, but id think there is a theoretical limit on weight, all things being equal, user etc.
I think you'd struggle to get a shell to weigh much less than 200g for an average user then 50mm of 1000fp down for ~-6, 4-500g minimum? Probably 6-800g for -6 total ?
An extra 100g of down is the most efficient way to spend weight imho, so I wouldn't sweat it too much.

Rab threw that theory out the window with the Mythic Ultra 180 and the 360...The unique heat reflective TILT Titanium inner coating allowed them to use less down to achieve the same warmth, which in turn saved a lot of weight. I have been comfy and warm overnight at -3'C (26.6'F) in my Mk1 180, which only weighs 420g, and the Mk2 360 is rated at -8'C comfort (17.6'F) and it weighs about 650g.

 

[Alf Outdoors]

agree - i tried the rab ultra bags, and there are trade offs like a zip thats not even a foot long, so you have to slide into the bag, that and the fill looked so pathetic compared to the promo pics,

im happy with what i have and even though its not ul i just dont like quilts, that being said ,my summer bag is 550g and will go to 0 my winter bag is 850g and will go past -6 tested with me in it, i have a wm nanolite at 312 g app will go to 0 but its the wind and stuff with that as its a quilt,

Only the Mythic Ultra 180 has the short zip...The 360's zip is about 41" (104cm) long.

 

[Enzo]

My best predicted specs were -6 c for 600g.
Rabs specs -8 for 650g.
Perhaps thrown out the window is a little hyperbolic?
650 - 360 =290, not a bad shell weight for a full on sleeping bag with hood and zip, my preference is simpler, so sub 600g definitely possible.

I'd be interested in IR reflective fabric for sure, seems to work with neoairs. Though I suspect their effectiveness is more to do with the chambers reducing convection.

 

[Jww]

Only the Mythic Ultra 180 has the short zip...The 360's zip is about 41" (104cm) long.

i tried the one without the hood too

these

Mythic Ultra 120 Modular Down Sleeping Bag

Rab Mythic Ultra 120 Modular Down Sleeping Bag available at Ultralight Outdoor Gear with FREE UK+EU Delivery, in-depth reviews, full tech specs & helpful buying advice.

ultralightoutdoorgear.co.uk

Mythic Ultra 180 Down Sleeping Bag

Rab Mythic Ultra 180 Down Sleeping Bag available at Ultralight Outdoor Gear with FREE UK+EU Delivery, in-depth reviews, full tech specs & helpful buying advice.

ultralightoutdoorgear.co.uk

i did like the low weight, and i think the blue mythic was a better spec from memory,

im quite happy with the exped, they really under rate their figure

my 'summer' bag is 640g (340g of 900eu/fill)
my winter bag is 940g (540g of 900eu/fill)

so not light by any means, but its a happy medium for me,

 

[Enzo]

I'd say those were good sensible ultralight specs, under a kg for a winter bag is not to be sniffed at. I'm no expert but have made quite a few quilts and bags and tried to optimise the designs.
Shell of my current quilt is mix of 10d taffeta and 7d robic wpb, 160g for reference. Hard to drop much weight from that sensibly.
I get the logic of only having insulation on the top plus around legs, but for me that heading down the road of so lite it's a pain to use.
Been there and happy to prioritise ease of use!

 

[Jww]

The expeds are h construction so can push the down above the body

 

[Jaco]

Rab threw that theory out the window with the Mythic Ultra 180 and the 360...The unique heat reflective TILT Titanium inner coating allowed them to use less down to achieve the same warmth, which in turn saved a lot of weight. I have been comfy and warm overnight at -3'C (26.6'F) in my Mk1 180, which only weighs 420g, and the Mk2 360 is rated at -8'C comfort (17.6'F) and it weighs about 650g.

Would you say the current 360 is worth £450, new?

 

[BogTrotter]

Yeah i sent you the link iirc

Im all sorted for bags now thank you

I settled on exped bags, 900fill, full zips and really comfortable and warm

I remember seeing your image of the Exped and Sierra Designs bags together and thinking you’d be a fool to get rid of the Exped.

It’s always on my mind when people discuss sleeping bags and how similar they seem to the PHD 400 I have. There seems, for some reason, to be some disconnect on pricing for these. I checked today and the Exped is £500 and the PHD is £650 ( PHD is lighter… I’d guess by 150g - just because that’s the way things work ).

Loft on the Exped looked great.

 

[Jww]

I got mine in the sale i paid £500 for two exped bags

 

[Alf Outdoors]

Would you say the current 360 is worth £450, new?

If you can get a new one for £450 new, definitely! I got mine with £100 off and I paid £560!

 

[sherpa]

I bought both of my Mythic Ultra bags from Alpinetrek.

They have an excellent summer sale each August - generous discounts, plus short duration "extra 10% off" offers - so with good timing & some luck on what's on sale/in stock, relative bargains can be had

 

[Jaco]

If you can get a new one for £450 new, definitely! I got mine with £100 off and I paid £560!

Thanks, it's food for thought. The similarly priced Małachowski bag has 500g of down at +50g of weight. Decisions, decisions.

 

[Winki]

Thanks, it's food for thought. The similarly priced Małachowski bag has 500g of down at +50g of weight. Decisions, decisions.

Nothing in a Cumulus custom any good?