by creeping_moses » Sat 09 Jun, 2012 1:16 pm
Bivy bags are mad good. I've got a 800 fill-down sleeping bag (mountain hardware wraith SL) that I have used on its lonesome outside at about 0 degree (wearing thermals and beanie) and have been perfectly happy in it, including a windy night on the Snowy Range just below the summit of Snowy South. When I use my bivy (Outdoor Research Alpine) with the bag, I'm normally a sweaty dog. The Bivy bag is only needed in my case when there are medium rainfalls, or anything heavier obviously, and its useful on windy nights to keep your face warm. I think what I am trying to say is that from my experience with bivies, I only use them when I have to, and if you dont want to buy multiple sleeping bags, just get one that is rated to very low temps, and use it to its full potential. So it follows from that, that I walk with my wraith SL bag, which is fairly bulky but I squeeze it into a sea2summit medium event stuffsack which gets it down to a very reasonable size and then carry my bivy which is light and small at all times incase its raining/windy/amazingly cold enough to warrant it. Its even possible to use the bivy without a mat in the case of my sleeping bag if I want to be lighter, but with a neoair, its hardly a burden.
I really want to try the wraith SL on a neoair mat in the snow. People have done it before and written/posted videos of it online and have said its fine, but would be interesting.
Also, I'd stay away from bivy bags that dont have a small loop pole to keep the shell off your face. My mate has one (a macpac one, which is very lightweight and nicely built from eVent) but it literally rests directly on your face, which he has assured me is most unpleasant when its pouring rain. That being said, if you want to use it in a tent, or hut (which seems a little weird to me) the fabric resting on your face might not be so bad.