can t stay warm

It might be your pad. The regular BA Aircore has no insulation and most definately would be cold at that temp. I know people that have found the BA Insulated Aircore cold in the 40's even though it is rated to 15*. You might try putting a CC Foam pad on top and see what happens.

Marmot is known for being "optimistic" in its bag warmth rating (not that it is the only one) — but that aside, I think Brad is right: the BA Air Core is really a two-season air mattress. For three-season use, you should get the Insulated Air Core or similar.

I've used my arroyo on a night when temps hit 15F and was warm; of course, I doubled up on pads, wore midweight base layers and expedition fleece, and had a down vest draped over my torso. I've also been cold in it on a night in the low 40s, but in that case I was in a tee shirt and underwear, used a 3/4 length pad, it was very damp, and I was in a large tent. But, you're probably right about needing a 15-20F bag if you're thinking about three seasons in the sierras, unless you can augment with down garments.

You're going to have a bit of trouble coming up with a true 15F bag under 3 lbs and $250. About the closest I've seen is the MH Phantom, which is on sale for around $300 at campmor.com, and weighs just over 2 lbs in a long. You could also go for something like a marmot sawtooth, which retails for around $230 and weighs just over 3 lbs. You could possibly also try out a JRB sierra sniveller quilt, which runs $279 for a long and weighs 24 oz. A down bag is one piece of gear where you get what you pay for.

Definitely a cold pad.
And maybe eat more dinner.

Cheers

Start with a warmer pad. For a plain BA Aircore, or a NeoAir, add a 1/4" CCF pad when it's below 40* F and a 1/2" CCF pad when it's below freezing. My experience is with the NeoAir (brrrr!) and with the POE Insulmat Max Thermo (now, I believe, called the Ether Thermo. The POE insulated air pad requires a supplement (for me) when temps reach the mid to low 20's F. A 1/8" pad has been fine for me so far. I don't know about the BA insulated air pad, but I would assume a similar situation. Better too much pad than too little!

If the warmer pad doesn't work, then get a warmer sleeping bag.

Some vigorous exercise at bedtime, which revs up your metabolic rate to help your body warm the sleeping bag, also helps. So does, as Roger mentions, the food.

I personally prefer a 20*F bag in the conditions you're using, but I am definitely a cold sleeper. I have a Western Mountaineering Ultralight Super and it is worth every penny (lots of them!) that I spent on it. You can extend the bag by wearing more insulating clothing inside it.

It's actually fairly easy to tell if it's your sleeping bag or your pad by lying on your back. If your back muscles are shivering while your chest muscles are warm, it's pretty obvious that it's the pad!

The EN 13537 LLimit value for this bag is 30.7F; the bag is correctly rated. The OP needs to understand that he will only achieve this rating with a sleeping pad at least as warm as what is used to rate the bag (R value 4.8).

I wouldn't say that Marmot bags are known for being optimistic Ben. In fact it seems with the exception on the Pounder and Pounder Plus, most all of their bag ratings are spot on with the EN ratings.

For the Arroyo the numbers are:

EN 13537 Tested
(Learn to read EN numbers.)
Comfort: 39.9F / 4.4C (Woman's Rating)
Lower Limit: 30.7F / -0.7C (Men's Rating)
Extreme: 2.3F / -16.5C (Woman's Hypothermia Limit)

It was the Pounder that I had in mind when I wrote the above. I thought Marmot was pretty dishonest — like "doing a Slumberjack". While warmth is subjective — I recall fairly consistent complaints about the Pounder being cold — and none at all going the other way.

In NW Canada we use the 'Bill Mason' system of an inner or summer down bag and an outer synthetic bag, and wear down pants, down jacket, quallofil booties, polypropilene contact gloves, mid weight pile long-underwear top and bottoms, and a pile balaclava. -5C (+20F) rating for us that is a 'summer' bag, with a Wallcreeper synthetic overbag on top of that, on a full-length, full-width Thermarest,(T-rest) with your foam sitz-pad under the torso. The T-rest LE(50mm thick, pretty much solid foam core) is the equivalent of 2 caribou skins if you can get those! For -10C (+10F) and below, full-length 18mm thick Evazolite foam pad under the T-rest as well. One time in a mishap, the T-rest LE got left behind and I used just the Evazolite, and at -10C I froze!

Finally, for winter camping, the cookie ration is right out of sight, I budget 600grammes per person per day of mostly-chocolate cookies! Danish butter (tinned) or cheese is also a big hit in winter temps. Rations have to be in the 5000calories a day range in order not to freeze! Hot drinks all round too! Keep hydrated=better blood flow! Wide-mouth thermos-mugs with a full stainless steel vacuum liner, are what we eat and drink out of!

I know this will sound like heresy on a SUL site, but this is what I do, and so far, it actually works!

I gradually have become a fan of the Kifaru woodstoves and rollable sheet metal chimneys; so these are worth a look at as well if you are interested in drying accumulated body vapour out of your clothes and sleeping gear. While a vapour barrier system works, I don't find it a lot of fun to use!

I agree with you on the Pounder and Pounder Plus Ben. That is pretty dishonest, as both of them are way off their EN rating, like 15* off.

Richard, do you have a chart of different R-Values for pads needed at different temperatures?

Bradford,

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=20434&skip_to_post=163244#163244

im selling a 20 degree kelty light year synthetic bag that weighs exactly 3 lbs in the long size for $80 in the gear swap.

i've used it down to 10 degrees and i'll be warm for you as long as you have a pad that will keep the ground from chilling you. i would also recommend getting a silk liner since it will make it a bit more comfortable, will insulate a little more, and will keep your sleeping bag clean.

I think Richard meant post 163242 directly above the one in his link. Anyway, from that graph (and a couple other posts of his I've seen) I infer that you need at least an R4 pad for 0C ground surface temp and above and that the ground surface temp will almost never be below -5C from the graph (or -10.5C from Richard's 11/13/08 post). I've seen him recommend R5 pad(s) to stay thermally neutral – anything more would allow you to "gain" heat during the night I guess but weigh more also (in general). This is if you are the average 30 year old male with .6 clo of long underwear to sleep in. So if you wear insulation layers to bed, I'd infer that I could go with less R value in the pad.

I haven't tried testing my NeoAir and REI Sub Kilo yet, but will soon.

Oh, and thank you, Richard, for sharing your expertise with the rest of us. I've not used most of the physics and thermo I had in college so your's (and Roger's) discussions are particularly enjoyable for me.

Hi Paul

> The T-rest LE(50mm thick, pretty much solid foam core) is the equivalent of
> 2 caribou skins if you can get those! For -10C (+10F) and below, full-length
> 18mm thick Evazolite foam pad under the T-rest as well.
Another LE owner! A wonderful mat – sadly unreplaceable. Dunno about the caribou skins tho' – never seen one :-)

I manage with the LE down to below -10 C without any CCF under it. Just how far below it would work I am not sure. I find the snow under the mat warms up a bit – a shallow hip-hole often forms and distributes the pressure. Very comfortable.

Heresy on an SUL site? Nope – staying warm is more important. (Pass another choccy bikkie please.)

Cheers

Take a hand warmer packet to bed with you (the iron oxide kind). They're light and they put out a lot of heat for a long time.

I just got this bag for Xmas, have been in it down to 21F with no socks on. Had to figure out to use a fleece earband over my nose but had a Thermarest Pro Plus and RidgeRest. $139 at the link below.

http://www.travelcountry.com/shop/mountain-hardwear/expedition-superlight-sleeping-bags/mountain-hardwear-ultralamina-15-sleeping-bag-15-deg.html

Oh as far as specs, 2 lb 14 oz, I am 6' and 200 and it fits well. It does not close in on your face as small as other bags but has 4 zippers so you can get your arms out while being in mummy position. I have also had my Columbia down liner on and a pair of liner gloves so I could side-sleep on my arms and that was also comfy for me.

thanks to all for the great advice and information

i think before i buy a new bag ive pretty much made up my mind to try and make the arroyo work for me im thinking i will try a cc foam pad on top of my air core pad and then add a patagonia micro puff zip vest (10 oz) to my pack
for an extra layer even if i just drape it over me inside the bag i don t feel like the bag is too far off in its rating i think mostly i just need a little warmer sleeping layer setup along with a warmer pad
if anyone has suggestions on this patagonia vest or any others that i might consider please chime in i think i will be fine with this setup but we will see
again thanks for the info
kevin

A full bladder in the middle of the night can also cause you to be cold.

Matti

Kevin-
Buy a warmer pad! Seriously. It's not about the insulation of your bag. The problems are the pad, which accounts for ~35% of your insulation and serves as the basis for the temp rating of your bag. Your current pad has a R-value of roughly 0. You need a R-value of roughly 5 to allow your bag to reach its rating. A T-rest Ridge Rest (ccf pad) has an R-value of 2.2. So you'd still sleep cold, regardless of what other layers you add on your torso. Check out an Exped Downmat 7 (R 5.9), a Thermarest Women's Trail Pro (R 5.1), or a Women's Prolite Plus (R 4.5). I don't think you'll find you need to make any changes to your clothing if you make the pad change. Best of luck.

It sure sounds like the pad is the place to start.

I always sleep cold. Roger Caffin suggested that I look at heat loss through the head also. I bought a BPL Cocoon 60 baclava, and that has mostly fixed my problem along with his suggestion of a good hot meal.

Thanks Roger!!

My buddy and did the Evolution Traverse last year and I used my 35* WM Highlite bag. We bivied a few times at or about 13k and temps dropped into the low 20's but I stayed warm. My trick is to bump up my bags temp rating with down booties and my down hat by Black Rock Gear. I really think adding warmth in the right places can make all the difference.