UKC

Hi all,

Im off to the alps for the first two weeks of March and am trying to decide which sleeping bag to buy. I’ll be using it for bivvys  up on routes (3-4000m ish) so needs to be warm + light. If you have any experience doing this kind of climbing, what would you recommend? Currently looking at alpkit alpinedream 800 or 1000.

Cheers,

Will 

Depends a bit on how warm/cold you sleep, but I'd suggest that an 800 or 1000 fill bag like you're looking at is way too much. The 1000 alpkit one weighs 1.5kg!

You'll have all your kit on and it's a bivi so you just have to accept you're not going to be super comfortable. Something in the 400-600 range is probably better, I use a Rab Mythic 600 (and really rate it!) but this is certainly a concession to comfort and I'm sure I could use something lighter.

There's a lot to weigh up in selecting a bag and often hard to reduce to one choice (I've got 2 and  a poss 3rd for diff situations/temps), but Andy's discussion via the link below covers the main issues:

https://www.andy-kirkpatrick.com/articles/view/sleep_tight

But don't underestimate how cold you can get if you're genuinely bivvying. 

John C

How much do you want to spend is really the big question as the difference in prices between 800 fill goose and 700 fill duck down is significant

The mountain equipment Xeros is mega and super light , I have one, only used down to -6 ISH but not a hint of being cold , snug fit and the long version would be a good shout if you are over 5.10

You can get the mountain equipment helium which is duck down for a much cheaper price, the 800 is warmer and £100 cheaper for a 200 gram weight penalty

If you are a bigger person I think the helium is a slightly more roomy fit

Rab neutrino is also a good bet if your can find a deal

i have been having this dilema recently. 

I currently own a 600 fill (750 fill power) bag and always found it way too warm (including on bivvys on Eiger NF in February, Dru in March etc) and its also pretty heafty at 1.1kg

I think the sweet spot is probably a 400 fill bag, but cos i am a cheap skate im currently thinking i might buy a 200 (800FP) bag, so i can use it for summer and also for bike touring, and then buy an additional cheap decathlon down jacket to wear under my big down jacket to boost the warmth of a 200 bag for late march / april bivying and also just expect to suffer. It really depnds on how many bivvys you are thinking you'll need. Unless your climbing mega hard, or you are slow and fat, its unlikely your going to have more than 1 (max two bivvys) in which case a thin bag and a bit of suffering will be fine, but if you are out for three nights on something hard, you definitely want 400 fill or warmer. 

Sounds like I am going to be absolutly roasting in my 800 fill bag

I’ve used a Marmot Lithium to bivvy on the Argy glacier in late March. I guess it must have been a few degrees below zero overnight, so not that cold. It was fine. That’s an 800 fill bag but it was a few years old at that stage. They do seem to thin out over time, especially on the back. Talking of which, a quality mat is equally important. I like the Neoair and on snow there’s no risk of puncture - although I’ve used it on rock lots of times and haven’t had any issues yet.

One point to note is not to skimp on the bag size. You want to be able to get your boots (if using climbing boots - ski boots probably won’t fit anyway) and gas + stove in it.

I think the crux of the issue is that the temperatures can vary so wildly these days (maybe they always did?). 

Climbing around Chamonix in the last week of Feb/first week of March I’ve had nights in the Abri Simond that have got down to -26’c but I’ve also had weeks where we were skiing in to routes in T-shirts because it was so warm. Obviously it’s usually somewhere in between!

So do you get a bag for ‘average’ conditions or ‘worse case scenario’ conditions? Depends a bit on what you’re doing… how committing your plans will be, how many consecutive nights, etc. Personally I have a Rab Neutrino 800 and don’t begrudge the extra 200-300g for the peace of mind of an extra 5-10’c of leeway over lighter bags. Pack size isn’t much different to lighter bags either. I’m sometimes too warm but you can always unzip!

Maybe I’m just soft compared to a lot of the posters above, but I think the extra tiny bit of weight is inconsequential compared to how brutally hard a day of alpine climbing feels after no sleep and you’re exhausted because you’ve used most of your calories up staying warm! History records all of the double hard guys and girls who summit a hard techy route after three consecutive shiver bivvys, but it doesn’t publicise the ones that woke up in the morning and bailed after a heinous night. I reckon the latter list is probably a lot longer!

Also, echo Misha’s tip for ensuring there’s enough space for inner boots, water bottle, gas and stuff with batteries like your avi tranceiver… you only forget to keep these things warm once!

Thanks for all responses. I ended up buying an Alpkit Alpinedream 800, which was appreciated on a -20 summit bivvy. I could have gotten away with a 600 bag but it was nice to push on knowing we had a warm night rather than a shiver night.