Sleeping bag questions: int. dimensions VS warmth

10:11 a.m. on February 1, 2003 (EST)
(Guest)

Hello everyone,

I'm about to make a new sleeping bag purchase. I'm getting a bag for use in the NC mountains in fall, winter, and spring. I'm stuck right now though, with trying to decide between a Western Mountaineering Antelope SMF (5*) or a Apache SMF with overfill (10*). I was talking to Gary Patterson at WM, and he was saying that the Apache with overfill might turn out to be as warm for me as the Antelope, becuase it has a slimmer, more efficient cut (59" shoulder vs 62"). I'm 5'9", 150lbs, and he said I would fit fine in the Apache, and I don't need much wiggle room: often end up sleeping on my side. So, the Antelope has an inch more loft, but the Apache has a smaller space for me to heat up.

How much will the smaller volume affect the bag's warmth? Which bag do you think would be warmer for this skinny cold sleeper?(if the difference is negligable I may go with to Apache and save 5oz)

Let me know your opinions.

Thanks a bunch!

4:06 p.m. on February 1, 2003 (EST)
37 reviewer rep
747 forum posts

Quote:

I'm about to make a new sleeping bag purchase. I'm getting a bag for use in the NC mountains in fall, winter, and springthe Apache with overfill might turn out to be as warm for me as the Antelope, becuase it has a slimmer, more efficient cut (59" shoulder vs 62"). I'm 5'9", 150lbs, and he said I would fit fine in the Apache, and I don't need much wiggle room: often end up sleeping on my side. So, the Antelope has an inch more loft, but the Apache has a smaller space for me to heat up.

How much will the smaller volume affect the bag's warmth?

You can be cold in a huge thick bag that fits loosely, and conversly you can always warm up by limiting the amount of air pockets inside your bag. My bag has four custom elastic bands inside it to hold it gently against me regadless of what I am wearing inside the bag (its too big for me otherwise). This makes a great compromise of a bag that is very toasty and allows dressing inside it. BTW its a Western super Kodiak -5 GTX and weighs 56 ounces and it is a genuine -5 bag for me.

So what you have to do is put on your "pajamas" and climb into both bags and try them out. Snug fit is best, but clastrophbia is bad and you will have to get into one then the other and decide - and is the room to put on any extra layers inside the one you choose?
I have a Marmot Pinnacle and it may be all the winter I need with the warm clothes I carry, like I have a winter down stuffed goretex suit that allows me to sit in the wind at -10F and be cozy warm. Its kind of like a medium weight 8000 meter suit and frankly I could survive in awful weather in it without a sleeping bag at all.
Jim S
P.S. I wouldn't worry about 5 ounces of weight in a winter bag, especially if its down weight.
P.P.S. Get a Warmlight down filled airmattress and be really warm and comfy and they only weigh 28 ounces - see get a warmlight and you can carry an extra pound of down.

8:17 a.m. on February 3, 2003 (EST)
0 reviewer rep
408 forum posts
Diminishing return...

Quote:

Quote:

I'm about to make a new sleeping bag purchase. I'm getting a bag for use in the NC mountains in fall, winter, and springthe Apache with overfill might turn out to be as warm for me as the Antelope, becuase it has a slimmer, more efficient cut (59" shoulder vs 62"). I'm 5'9", 150lbs, and he said I would fit fine in the Apache, and I don't need much wiggle room: often end up sleeping on my side. So, the Antelope has an inch more loft, but the Apache has a smaller space for me to heat up.

How much will the smaller volume affect the bag's warmth?

You can be cold in a huge thick bag that fits loosely, and conversly you can always warm up by limiting the amount of air pockets inside your bag.

Hmmm....I'd argue that if you fit too snugly in especially a down bag, that you defeat the loft thru compression of the tight fit. I don't fit Western bags, and have noticed this problem in other bags.

I routinely lend "the hilton", my huge used-to-be -30 feathered friends bag to a very diminutive climbing partner. No chance they get cold in that thing because its too big. Just more dead air space. Er something...

And, in a larger cut bag, if you're cold, you can always add clothing layers.

Quote:

P.S. I wouldn't worry about 5 ounces of weight in a winter bag, especially if its down weight.

Overfill seems to be a nice option. I got overfill in my last down bag (FF Raven). Wonder how much diff it makes...

Quote:

P.P.S. Get a Warmlight down filled airmattress and be really warm and comfy and they only weigh 28 ounces - see get a warmlight and you can carry an extra pound of down.

Seems inefficient. Wouldn't it be better to have down on top and just air below? Anyone know the R-value difference in an air mattress vs a down filled one? Interesting concept. 28 ounces seems heavy for an air mattress. Thermarests in ultra light weigh around a pound or less (3/4 length). In combo with a non poppable closed cell foam pad at under a pound...(say, 440g + 350g = 790 which is close to 28 oz I'm guessing...453.6 g/lb...).

Brian in SLC

11:08 a.m. on February 3, 2003 (EST)
37 reviewer rep
747 forum posts
Insulation under = warmth

Quote:

Hmmm....I'd argue that if you fit too snugly in especially a down bag, that you defeat the loft thru compression of the tight fit.

The inner bag is smaller than the outer layer. How snugly you fit inside (within limits I guess)has no effect on the loft.

Quote:

Quote:

P.P.S. Get a Warmlight down filled airmattress and be really warm and comfy and they only weigh 28 ounces - see get a warmlight and you can carry an extra pound of down.

Seems inefficient. Wouldn't it be better to have down on top and just air below? Anyone know the R-value difference in an air mattress vs a down filled one? Interesting concept. 28 ounces seems heavy for an air mattress. Thermarests in ultra light weigh around a pound or less (3/4 length). In combo with a non poppable closed cell foam pad at under a pound...(say, 440g + 350g = 790 which is close to 28 oz I'm guessing...453.6 g/lb...).

Thw warmlight is 3 inches thick. Do you sleep on one ultrlight mattress on the snow?
Jim S

1:27 p.m. on February 3, 2003 (EST)
0 reviewer rep
408 forum posts
Dead air higher R value??

Quote:

Quote:

Hmmm....I'd argue that if you fit too snugly in especially a down bag, that you defeat the loft thru compression of the tight fit.

The inner bag is smaller than the outer layer. How snugly you fit inside (within limits I guess)has no effect on the loft.

In most sleeping bags, I think the inner layer is sized to fit with the loft and outer layer. If the fit is tight for me, it automatically translates into compression of the loft, which negates any insulating effect. I've demo'd several sleeping bags in front of shop folk pretty familiar with sleeping bag construction. Pretty much universally said, whoa, too tight, it won't keep you warm. IMHO too, anyhoo. YMMV. If I get a chance, I'll chat w/ the sleepin' bag folk this pm before they pack up shop, since most are here in the briney pond village...

Quote:

Quote:

Quote:

P.P.S. Get a Warmlight down filled airmattress and be really warm and comfy and they only weigh 28 ounces - see get a warmlight and you can carry an extra pound of down.

Seems inefficient. Wouldn't it be better to have down on top and just air below? Anyone know the R-value difference in an air mattress vs a down filled one? Interesting concept. 28 ounces seems heavy for an air mattress. Thermarests in ultra light weigh around a pound or less (3/4 length). In combo with a non poppable closed cell foam pad at under a pound...(say, 440g + 350g = 790 which is close to 28 oz I'm guessing...453.6 g/lb...).

Thw warmlight is 3 inches thick. Do you sleep on one ultrlight mattress on the snow?

I usually use a 3/4 ultralight in combo with a closed cell foam pad. Havin' your air mattress pop is a bit of a bummer. Not just 'cause the ground is cold...its hard too! A lesson learned the "hard" way...har har...

The warmlight stuff is interesting. I'll have to check on it. Website?

Brian in SLC

5:52 p.m. on February 3, 2003 (EST)
(Guest)

May I Butt In With A Followup Question ????

I have a related question that I was going to ask this week. I went snow camping last weekend (igloos and everything out of Paradise on Mr. Rainer). It was the first time I used my Sierra Designs Flex model sleeping bag and I had a hard time dealing with it (in other words, I freaked out) because I am slightly claustrophobic. At one point I unzipped down to my waist just to get away from the tightness, not a good idea at 3am at 25 degree weather (I'm lucky it didn't get colder).

I specifically purchased the Flex model because it allows for expansion. I guess not enough for me. I couldn't deal with my arms being pinned down. It was a miserable night (either cold or stressed out).

My question, is there a decent synthetic (maybe Polargaurd 3D) backpacking (meaning somewhat light) sleeping bag that isn't so tight around the body, especially the arms and shoulders? I don't seem to have a problem with my car-camping bag (Coleman-large rectangle-extra heavy). I am a warm sleeper and would rather focus on size and shape rather than warmth. Or is the trade-off too much? The vast majority of my backpacking is 3-season weather.

Let me know your opinions.

Thanks a bunch!

10:35 a.m. on February 4, 2003 (EST)
(Guest)

Follow-up Info and Further Reflection

I'm 6 foot tall, 200 lbs, athletic build with 34-36 waist and size 44 long coat. The bag is rated to 35 degrees and I knew it would be colder (predicted upper teens) so I also used a fleece bag liner and lots of layers of clothing (t-shirt, med-weight fleece, marmot windshirt, stretch nylon runners' pants, two pairs of wool socks, turtle fur fleece hat).

I tried the bag again last night (in the house) with just long undies. Seemed to have enough space then. Leads me to believe that anyone might feel cramped with my size and all that extra stuff I had in there for my trip. I knew it was an experiment to try to extend the bag past its rating with clothing but I wanted to try it just to see if it works (the ultralight crowd seems to think so). (A somewhat safe experiment because I knew I would be camping with experienced snow campers and we were camping within 20 minutes of the cars.) Perhaps this system (bag with lots of clothing) works for some but not for me because I need the space to move around.


Live and learn. (And I think the bag will work great for me for three season camping.)

7:12 p.m. on February 8, 2003 (EST)
37 reviewer rep
747 forum posts
Re: Follow-up Info and Further Reflection

>Perhaps this system (bag with lots of clothing) works for >some but not for me because I need the space to move >around.

I think restrictive clothing inside the sleeping bag (Read multiple fleece layering)is a major claustrophobia initiator. Too many layers bind and twist and it feels like yer wrapped up in the bag but its really the clothes. Thats why I normally only wear mid weight long underwear and maybe a microfleece jacket which is far less strangling than a fleece jacket. I really do not reccommend a lot of fleece nor fleece jackets for sleeping in for claustrophobic people. I do sometimes pull on a pair of down pants in my sleeping bag, but if I was still cold I would put my down jacket over the top of my bag so my body would keep the inside of top part of the bag warm.

That said. I have a Western super Kodiak bag which is big enough for an NBA player. I am not that big and the bag was never real warm for me because of that but it has lots of room to stretch out in. Solution - I cut 4 small slits on on the inside shell on each side by the zippers. Then I pushed four very thin pieces of elastic through to the other side and sewed the ends down after adjusting the tension on them. These inner elastic bands pull the bag gentley up to me. This even helps the bag loft more cause it pulls the bag up around me rather than laying more flat. There is very little dead air space in the bag, and the bag is divided into 5 small inner pockets that do not pass wind from one to the other. I have a huge warm bag that hugs me AND I can stretch in any direction! It also easily expands to comfortabley handle anything I want to wear inside it - like down pants or bibs. Might even fit in a wife...

Another thing - for three season there might be a lot to be said for just carrying a warm jacket and an elephant foot bag (a short sleeping bag that covers you from the waist down.) When Bill S was a kid - down pants had zippers on the inside of the legs so they could zip together into a sleeping bag. WHY? Because the legs are warmer if they do not have insulation between them. In extremes when wearing a lot of clothes, it can be freezing cold inside your sleeping bag and you need gloves to keep yer hands warm. There are limits and YMMV.
Jim S

October 20, 2014
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