Reviewer Information:
Name: Jim Hatch
Age: 44
Gender: Male
Height: 5'9" (1.8 m)
Weight: 180 lbs (82 kg)
Chest: 44" (112 cm)
Shoulder Width: 21" (53 cm)
Hip Width: 16" (41 cm)
Sleep Type: Back & side sleeper (neither warm nor cold)
Email: colonelcorn76@yahoo.com
City/State: Simsbury, Connecticut
Date: August 13, 2004

Backpacking Background:
I've been backpacking and camping for 30 years (ever since I was a Boy Scout). I'm out once a month for a weekend or more and for 5 nights or more, 2 or 3 times during the year. Most of my backpacking is done in the mountains of the East Coast (Appalachians, Whites, Berkshires, Adirondacks) but I will occasionally camp as far south as the Florida Keys or as far west as the Grand Canyon. Having tired of 60 lb (27 kg) loads, I caught the lightweight bug about 5 years ago and am currently carrying a base pack weight of less than 10 lbs (4.5 kg) before food and fuel and rarely venture out with more than 20 lbs (9 kg) anymore. I am now trying to develop a low-volume style to go with the lightweight nature of my gear.

Product Information:
Manufacturer: Big Agnes, Inc.
Year of Manufacture: 2004
URL: http://www.bigagnes.com
Style: Mummy shaped air mattress, PrimaLoft filled
Mfg Temp Range: down to 15 F (-9 C)
Mfg Weight (web): 21 oz (595 g)
Mfg Weight (hangtag): 20 oz (567 g)
Tested Weight (mat): 18.9 oz (534 g)
Tested Weight (stuff sack): 1.2 oz (38 g)
Tested Total Weight: 20.1 oz (572 g)
Mfg Size: 20 in X 72 in (51 cm X 183 cm)
Tested Size: See below
Thickness: 2.5 in (6.4 cm)
Tested Rolled Size: 11 in X 4.5 in (28 cm X 11 cm)
MSRP: $65

Description:
As I noted in my Initial Review, the Big Agnes Air Core Insulated pad is a mummy (coffin) shaped air mattress with a layer of PrimaLoft insulation bonded to the underside of the top layer of fabric. Physically it is very small. Smaller than any other pad I have, including what only a year ago was billed as the smallest stuffing pad available (a self-inflating pad). Its weight puts it into the low to light weight category and the size puts it into (my favorite) the low volume one. Now that I've achieved low weight in my "big 3" I'm pushing for low-volume as well. Keep it light & keep it small is what I'm trying to go for.

The Air Core Insulated pad is a non-self-inflating pad that takes 14 full breaths to fill. That puts enough air in it to allow me to let a little air out to tune it for comfort while I'm laying on it without needing to get up again to add more air. When letting air out for adjustment I can do so by reaching up over my shoulder and twisting the valve slightly. If I let too much out I have to roll over and fill it (yeah, right...with all my weight on the pad I'm fighting myself to refill the mattress) or get off and add some air. The valve is located by my right ear which makes it easy to let some air out while staying in position to evaluate when to stop.

The stuff sack the pad goes into is a nicely constructed simple stuff sack with a slot/pocket sewn in the bottom which provides a very nice handle to pull on when removing the pad and a pocket in the dust flap that contains a small repair kit. Big Agnes has taken care to pay attention to all of the details.

Air Core Features:
According to the manufacturer, the Air Core Insulated is

Thermally efficient
Water resistant
Breathable
Lightweight and compressible
Fast drying
Soft

and:

Provides the best comfort to weight ratio of any pad
With the added PrimaLoft it's a 3 season pad that's super comfortable and lightweight
Unique I-beam construction allows the air to flow freely as you move for constant support and makes inflation and deflation quick and easy
Non-breakable valve with a lifetime warranty
Lightweight, durable 40 denier nylon fabric
And a repair kit is included

In my Initial Report I was able to verify that it was definitely lightweight, compressible and soft. Since then I have been able to verify Big Agnes' claims to thermal efficiency (at least within the temperature ranges I've experienced) and water resistance. I don't know if the valve is unbreakable or if the "best comfort to weight ratio" claim is true; but I can note that my pad does not leak air even after being inflated for a week or more at a time and that incidental water exposure (spilled water, dew, condensation) has no impact on the mattress at all. Whether the rest of the claims are true or not doesn't seem highly relevant to me now as the mattress meets my criteria for a backpacking pad:

Lightweight

Low-volume

Comfortable

Water resistant

Airtight

Field Results:

By and large I'm a tree-hanger. I only join the ground dwellers when the temps drop below 40 F (4 C). That means three seasons find me in a hammock and it's not until winter sets in that I hit the ground. In either case though, comfortable sleep is very (okay, extremely) important to me. In the hammock I'll use a reflective layer (Reflectix) or self-inflating pad when the temps go below about 60 F (15 C) because the air below my hammock will bleed the heat from me at lower temps. In a tent, I always use a pad or air-mattress because I've discovered that the ground is made up of rocks. Honestly. Anyone who claims it's dirt is forgetting that dirt is just very small rocks. Rocks are hard. I don't sleep well on rocks. So, out come the pads or mattress regardless of the temp.

So far, although the weather has been cooler than normal, nighttime temps on my monthly backpacking trips have generally been in the 40s to mid-50s F (4 to 13 C). That's hammock weather. With a traditional air mattress I'd need a reflective layer underneath because the air in the mattress still sucks heat away. The Big Agnes did not have this problem. I felt that I could have had a refrigerator under me without affecting the temperature of the mattress. The PrimaLoft layer does appear to keep the cold away from the surface of the pad (and therefore, me). I was usually wearing a t-shirt and underwear made of Coolmax or other wicking fabric and wool socks when sleeping. In the colder temps I also wore a polypro beanie to keep heat from fleeing my head.

My sleeping bag has been a Nunatak Arc-Alpinist. This bag has a 2 oz (57 g) overfill so it's rated to 10 F (-12 C). That might seem like overkill for spring/summer trips but except for a sewn-in footbox, it's a zipperless quilt design. That allows me to use as much or as little of it as I want based on the temperatures during the night. I start out with it tossed over my feet and slowly pull it over me as the night goes on. If it's really cold I can snug the straps that run from the side, under the mattress, and to clips on the other side. Snugging the straps can pull it so tight that it becomes a hoodless mummy bag.

I can tell when I sleep cold because I wake up needing to water the poison ivy. Warm comfortable sleep in the hammock results in me sleeping like the dead until everyone around me has awakened for the day. Even when it rained (half of the nights out) I slept through the night never needing to awaken for nature's call. Comfortable and warm. Definitely the combination I am looking for.

The Big Agnes pad is well suited to hammock camping and especially the Nunatak. Although it is made of nylon, the coffin shape seems to hold it in place better than the rectangular pads I use. This could be because it is a full length pad (my others are 3/4 length) but I suspect it also has something to do with the shape more closely matching mine. The fabric of the hammock envelopes me and the pad as we're the same shape (there's only about an inch/2.4 cm of mattress extending beyond my body on the sides). With a rectangular pad the fabric pulls up around the pad but not around me which allows me to slide around to the point that the pad slides out from underneath me & I wake up with a pad laying on me.

This shape is also very compatible with the Nunatak Arc-Alpinist. The Nunatak is a quilt with a full footbox. Rather than having a bottom layer like a sleeping bag, the Nunatak has 2 straps which are located about 1/3rd of the way from the top & bottom of the quilt. These straps are designed to run under a pad to clips on the other side. Pulling them tight brings the sides of the quilt around and slightly under the sleeper. The Big Agnes' narrow foot fits the footbox (if I want to slide it in) and the main body of the pad is narrow enough that I can snug the quilt around me & under the pad leaving no openings for cold air to find my sensitive parts. Together the three of these seems to form a near perfect sleep system for 3-season camping.

My only real issue with this system is rolling the Air Core up in the rain. The hammock doesn't really provide a firm surface on which to press when deflating and rolling the pad. That means I usually have to roll it up twice to get sufficient air out to fit it into the stuff sack. This isn't really BA specific though as most every inflatable pad has the same problem when used in a hammock. When it's not raining I will usually roll it up on the ground. Doing so requires that I brush dirt & pine needles off the surface as I roll as the nylon surface seems to attract debris (pine needles especially). In my idle moments I toy with the idea of a reverse inflator that would suck the air out of the mattress that would eliminate the need to squeeze the air out. But then I'll have finished the process and I go on to packing up the rest of my gear. (For a "what if" I tried it myself but it seems 14 lungfulls exhaling multiplies into dizzying quantities of inhalations so I've been unsuccessful in deflating by mouth.) The dirt & forest detritus I've picked up haven't had any real effect on the mattress though -- no tears, punctures, permanent stains, or noticeable abrasions.

What remains:
The real question I have has to do with how well the manufacturer's temperature rating holds up. The next few months will bring me to the edge of winter which, based on this summer's weather should bring colder than normal temperatures. I suspect it is entirely possible I'll find a night that tests the lower limits of the pad's temperature range (two years ago I awoke in upper state New York to 16 F/-9 C and 2 in/5 cm of snow on Columbus Day in the beginning of October). By then I'll be using a tent so I can evaluate its ground dwelling comfort (I have tried it with comfortable results at home, but that's not the same). I'll also be looking out for long term reliability in the areas of baffle construction (do they retain their ability to keep the insulation from sliding back & forth?), insulation integrity (does it continue to stay in place attached to the underside of the top layer of the mattress?), and airtightness (does it begin to leak with extended use?). With another half-dozen trips to the great outdoors, starting with a transit of the Presidential Range in New Hampshire's White Mountains next week, I should have ample opportunity to evaluate these remaining questions.

Read more reviews of Big Agnes gear
Read more gear reviews by Jim Hatch

Field Report