5’6″ WM bags, really that much of a difference?

[Chris .]

I have a 6' Versalite. I have always bought the 6' bags because sometimes I like to sleep late and burrow down and pull the bag over my head to hide the light. Recently I switched from a heavy hiking sock to a much thinner running sock for hiking and sleeping. Even in heavy socks before, my feet were a little cold, even when it was above freezing. Now that I am using the thinner sock, my feet FROZE last weekend, and it was only 38*. SO clearly I need to go back to sleeping in a heavier sock but I am wondering if all the free space between my feet and the bottom of the bag is making a difference as well. I am 5'7" but there seems to be more than 5" there. Should I go to a shorter bag?

[Stephen M]

Best to call WM directly, but when they say a short is 5' 6" they mean it.

[d k]

I emailed them once about length (I am 5'8") and they said that a 5'6" bag would end up being pulled tight over my feet, compressing the insulation too much and making my feet colder as a result.

Is there anyone near you that has a 5'6" WM bag you could crawl into as a trial to see if it is too short and pulls tight at your feet?

[Nathan V]

I am exactly 5'6" and have had two 5'6" WM bags, a Highlite and a Megalite. I just fit in them without any spare room, they weren't too small, but just long enough. Like Stephen said above, when they say 5'6", they mean it.

[Cameron Habib]

I know Feathered Friends does custom requests on their bags, I'm sure WM would do the same (for the right price). You could always ask to have a bag sized just to you.

My understanding about it is that there is an optimal amount of void space to allow loft, anything over which causes a decrease in warmth since it just increases the volume of air you need to heat. A little space is nice since I know some people throw a warm water bottle down there or, as you do, scrunch down in the bag, but 5 inches seems like a bit much.

[Stephen M]

Two tricks with a longer bag is to put some clothing in it to fill the space or push the end of bag in from the outside bottom.

[Marko Botsaris]

"Now that I am using the thinner sock, my feet FROZE last weekend, and it was only 38*."

I'm a fan of burrowing as well (a luxury of the short), and I also tend to have cold feet. If that is the specific problem you may be better off just getting a pair of down booties at about 2 oz. Also the socks themselves may be the issue if they are too tight as my "thiny-thin" socks tend to be for sleeping. Remember your feet have to actually HEAT the socks and bag in that area, so the better the blood supply the warmer the feet. There can be a bit of a negative feedback thermal "poverty trap" – once your feet get cold, increased vasoconstriction, so colder foot surface temperatures, so insulation is less effective, so colder feet….

Of course smaller total internal bag volume will help, but I'm thinking not so much if your feet are the only issue.

Lastly, again if your feet are the only issue, there is the very cheap solution of a vapor barrier – wrap you feet in plastic bags in a pinch. Between socks is VERY comfortable and warm. Also very useful for putting your feet in the frozen shoes in the morning.

[Linda Alvarez]

I ask this question with all sincerity: wouldn't cinching down or tucking the additional length back under (and perhaps securing with webbing or somesuch) be an effective means of reducing the bag volume? With the (admittedly probably negligible) bonus of adding additional insulation under your feet?

This is what I'm hoping to do to make an adult women's bag work for my 4' daughter. (After searching unsuccessfully for months for a decent LW down bag sized for a child) I plan to use one of my extra bags and then tuck the last foot and a half under itself so she doesn't have to warm up so much volume.

Just want to make sure I'm not missing something.

I guess of you're talking the difference between a 6' and a 5'6" there isn't much you could "tuck" but maybe cinching with some extra cord would be possible.

[J Mag]

I don't know the baffle design of WM bags as I don't own one but if you want to stay with the lighter socks you could look into redistributing some down towards your feet if the design allows (this is what I do) or getting half an ounce of down added in the foot section.

Of course if WM bags use sewn through baffles this could be impractical.

Just a random suggestion.

[Franco Darioli]

Linda
This is an easy way , as long as you have a rubber band :


about 10" reduction there but it can be any length you like
(yes you will have a warmer foot box)
BTW, you can shift down inside a WM bag side ways (from above to below) but not from top (head) to bottom (foot)

[Owen McMurrey]

I'm 5'7", and have always used 6' bags, and now quilts. I run about 15F warmer than EN ratings with the requisite pad and baselayers. Maybe that makes me an exception, but this "void" I'm always hearing about remains a mystery, as all my bags lay flat when empty, and settle around me when I'm in them. To hear people talk about having to warm all this dead space, you'd think they were rigid tubes or something. The extra length comes in handy for keeping water and filter from freezing, and the next morning's clothes warm.

Are you using a full length pad?
Having had mostly 3/4 length pads, I used to need an extra pair of socks, even clothing wrapped around my feet(guess a pack doesn't have much r value) when the rest of me was toasty, but switching to full length insulated inflatables for cold weather put an end to that.

[Aaron Sorensen]

My wife has a 5' 6" Helium.

I am 5' 11" and I can fit in it.
Both my toes and head push against the fabric but I can still sleep comfy inside it (barley).

5' 7" would give you 2 less inches top and bottom would work out even with your toes pointed.
I would say 5' 8" would have your toes hit, and 5' 9" would be about maxed out.

[Linda Alvarez]

Franco — that's genius! I'm off to add a giant rubber band to my pack list!

[Joe Clement]

No off switch on genius, is there Franco?

[Franco Darioli]

I take several of those thick rubber bands with me , they come handy for many uses.
The local Post Office leaves them for me on the footpath (pavement)

These are about 3" long , 1/4" high.
When applied to the SB for that liposuction type set up the band in place will be about 1" in diameter so you don't need a large one.

[Mary D]

One thing I never realized until I got a bad case of plantar fasciitis a couple of years ago: When you're lying on your back and relaxed, your feet automatically go into the pointy toe position. (That's the reason docs recommend a night splint for PF.) I'm 5'4", and when I stretch out full length on my back and relax in my 5'6" WM Ultralite, my toes touch the bottom. So if you're a back sleeper, even if you're 5'6" the bag will be too snug. Of course if you sleep on your side in the fetal position and don't stretch out, bag length isn't quite so critical.

There's also the question of protecting things like water filter and camera battery from freezing when you're shoulder season camping. In that case you need the extra room at the bottom of the bag. If my hiking clothes are damp or wet, I put them in a plastic ziplock bag and put that in the bottom of the bag. The clothes of course don't dry, but at least they are warm, not icy, when I put them on in the morning.

If your feet get cold, warmer foot coverings are definitely indicated. I wear down booties over loose wool socks. You can also send your current Versalite into WM for an overfill in the foot area.

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