Traditional Sleeping Bag Alternatives?

[erichkopp]

After using my Thermo-lite 2.0 Bivvy (http://www.rei.com/product/750938) on a few outings, I know it'll keep me comfortably warm to about 50* with a sleeping pad. I've been toying with the idea of layering that outside of something like a Sea to Summit Reactor liner bag (http://www.rei.com/product/797113) to be comfortable around freezing temps, and the breathable properties of the Sea to Summit bag would probably be a lot more comfortable than having just the Thermo-lite against my skin. It's rare for temps to drop too much below freezing here in Florida, and I'm thinking this setup would make a comfortable 3-season setup for most anywhere else in the SE.

The idea of packing my entire shelter and sleeping system in a smaller stuff sack than my 30* bag alone sounds really appealing, as does not relying on down to keep me warm if conditions are a bit wet (as usual down here). Anyone ever try anything like this?

[bmike-vt]

I would be amazed if the thermolite liner could get you to freezing with the bivy.  I have on of the older ones and use it as a liner - I don't think it adds more than a few degrees.  Let us know if it works - would be quite the kit.

[erichkopp]

I think it's being a bit optimistic, too, or else others would probably be doing it already, but it'd be a killer light-weight kit. What got me thinking it MIGHT work, is that Sea to Summit makes a few different liners, one of which claims to add up to an additional 25* while still packing in a 5"x7" stuff sack.

Now if only I'd quit riding so much and go and make some money, I could try this out 

[Marshal]

Actually two Thermo-lite 2.0 biveys and a pad (also a 6 oz down vest+ dry riding clothes) has worked very well for me on dry summer nights below 7000 ft.

note: I tried the same S-to-S liner with my regular bag in 30-40 deg conditions--did not add much if any warmth imo

[sean salach]

I've shivered through a night of somewhat restful sleep at about 40 with a Thermo-lite 2.0 and a coolmax liner, with most of my clothes on. For a light and fast setup, I would at least add a primaloft quilt or something light and small. If it's for racing you don't need much, but if you want any sort of comfort while you sleep, a little bit of warmth is worth it's weight in bacon.

[DoctorRad]

After using my Thermo-lite 2.0 Bivvy on a few outings...

Presumably completely non-breathable? Don't you get a bit sweaty in there?

[erichkopp]

Presumably completely non-breathable? Don't you get a bit sweaty in there?

When it's colder, not too much, but otherwise it does get stuffy. A wicking base layer helps for comfort and the bivy opens up to about halfway down, like a normal mummy bag. Primaloft quilt might be a good option as well.

[mmeiser]

This idea of using a thermolite to as one's primary bag is a bit crazy.  I like it.

I've got one that I'm planning on using as a vapor barrier this winter inside a down quilt with an Big Agnes AirCore primaloft insulated air mat. It ads quite a bit.  Not to mention it's quite comfortable with merino wool baselayers head to toe.

Am trying to decide wether to compliment this with a down jacket or my lafuma 45 degree syntetic 1lb 4oz bag.

All this will be in a gortex bivy, further inside a Shangri-la 3, sans poles.

There's a fine line between to much and too little. Unforetunately it's still to warm to get some good shakedowns in to dial it in.

[mmeiser]

damn, used quickpost, now i have to make another silly post to check "notify me of replies". Does anyone else find it silly that the only way to subscribe to a thread is to leave a comment? I don't get it.

[trebor]

i've been toying with an idea.... thermolite 2.0 with a strip (or two) of WPB fabric sewn in. Not too much so as to loose the reflective capability of the bivy, but maybe enough to hlep eliminate some condensation build up.

combine that with a BA air core and synthetic quilt for my sleep system from about freezing and above.

[mmeiser]

I like it.

but if you're already wearing something like merino wool, felt, a down jacket or something then it might be unecessary.

Then again having some sort of light thermal layer affixed to the reflective layer might be very effective heat wise and/or it might use capilary action to handle moisture on the bivy differently spreading it around so it doesn't build up all in one place or bead and drip. I guess one could also then flip it inside out in the morning to dry it out... but frankly I think it's easier to dry out clothes and to simply wipe down or shake off condensation that will turn to frost after you climb out of it in the morning.

BTW, slept in my new tent with my new bag last night. Only got down to 28.      Was more then comfortable with my new GoLite 20 down quilt, and golite shangri-la 3. But then i also had the OR aurora bivy and a BA air core mat underneath.  I think with the setup will easily exceed the bags 20 degree mark, especially with a head to toe merino base layer and a nalgene of hot water in the bottom.  What I'm debating is weather to carry my lafuma 45 degree syntetic 1lb 4oz bag... not a lot of weight and a little pack space, but should increase the range of the setup tremendously.  Seems to cover the down quilt well, but I worry that it will compress the down causing it to actually loose r-value.  Reminds me... maybe I should try the lafuma on the inside. It's not very heavy, and could be used in bag mode (instead of unzipped) Seems the down quilt can easily be expanded to cover it and there's more then enough room in the bivy so the quilt can fully loft.  Might just work.

[6thElement]

test

damn, used quickpost, now i have to make another silly post to check "notify me of replies". Does anyone else find it silly that the only way to subscribe to a thread is to leave a comment? I don't get it.

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