Big Agnes Insulated Air Core Inflatable Sleeping Pad

Product Information

Name: Big Agnes Insulated Air Core Inflatable Sleeping Pad
Model: 20x72x2.5 mummy pad
Maker: Big Agnes Inc.
http://www.bigagnes.com
MSRP: $65
Year of manufacture: 2004
Product type: Insulated three-season backpacking air mattress
Options: None available
Ships with: Stuffsack; repair kit (patches, glue, valve and o-ring); hangtags; brochure
Size tested: 20x72x2.5
Measured dimensions (inflated): 19.5 x 71.5 x 2.5 inches (49.5 x 181.5 x 6.5 cm)
Measured dimensions (deflated, folded and rolled for storage): 9.5 x 4 inches (24 x 10 cm)
Specified weight: 21 oz (595 g)
Measured weight: 18.6 oz (527 g)
Weight of stuffsack and repair kit: 1.0 oz (28 g)
Claimed low-temperature range: 15 deg. F (-9 deg. C)

Tester Information

Tester: Rick Dreher
Email: redbike64(at)hotmail(dot)com
Male
Height: 6 ft (1.83 meters)
Weight: 175 lb (79 kg, 12.5 stones)
Age: 50
Location: Northern California, USA
Years backpacking experience: 37
Backpacking skill level: Mid to advanced
Backpacking style: Lightweight, mostly alpine (see bio at end of report)

Report date: December 16, 2004

Introduction

The Big Agnes REM Air Core Mummy Pad (BA Air Core) is a compact and lightweight backpacker’s air mattress with added fiberfill insulation. The insulation is intended to extend the mattress’s temperature range beyond what’s possible on a standard air mattress, while still providing an air mattress’s superior comfort. For this test, it has delivered on most of these promises. In my experience, however, the low temperature range proved a bit short of that claimed by Big Agnes.

Design, Materials and Construction

Is it possible that this little black nylon stuffsack holds a full-length air mattress? Sure enough. The BA Air Core--fashioned of black 70D rip-stop nylon--folds into a very small package. Upon unfolding, there’s little hint of the insulation layer, but close inspection reveals perhaps a quarter inch (6 mm) of fiberfill attached to the mattress’s topside. The insulation is Primaloft Sport, a synthetic insulation with an established ability to still function when moist and to have reasonable resistance to loss of loft. In theory, the moisture from your breath going into the mattress while inflating it won’t rob the insulation of its ability to keep you warm (eliminating the need for an air pump as with down-filled air mattresses).

The BA Insulated Air Core is an air mattress fashioned from coated, somewhat slippery rip-stop nylon fabric. The mattress has eight tubes running lengthwise; the between-tube seams have inner fabric baffles, i.e., they aren’t welded through directly to the other side. The tested mummy-shaped Air Core might be described as coffin-shaped, a rectangle with the four corners lopped off at different angles at the head and foot ends. The lopped corners save bulk and weight over a rectangular pad (also available from BA); of course, it reduces sleeping area too. As I lie face-up on the pad with the insulated side (label side) also facing up, the plastic air valve is at my head to the right. This valve placement makes it convenient to release air for adjusting comfort without getting out of bed.

On first unrolling, it’s difficult to find tactile evidence of any insulation in the Air Core, but after several minutes inflated, a pinch test of both mattress sides reveals the insulation’s presence on top. I initially didn’t think It would be possible to figure out what’s going on inside without dissection, but then discovered that by holding the Air Core to the sun I can see the Primaloft batting strips in each tube. They appear to be held in place by the baffle-to top surface seam on one side only. I estimate each batting strip is about a quarter-inch (6 mm) thick.

Long-Term Report

Summary

The Air Core provides the most comfortable night’s sleep I’ve had since I abandoned backpacking air mattresses many years ago. It’s clearly more effective at keeping the stony ground at bay than my foam or self-inflating pads. It’s not as effective as those options at staving off the nighttime cold. As temperatures drift below freezing, I need extra insulation underneath me to sleep comfortably through the night, and I didn’t approach the maker’s claimed 15 deg. F (-9 deg. C) low-end range. I’d place something (clothing or a foam torso pad) underneath me, atop the mattress to keep warm. Once dialed in for the temperature and my sleeping bag, it’s heaven sleeping on the Air Core pad. Note: my sleeping bags during the test trips were down, and down fully compresses when underneath.

The Details

I took the BA Air Core into California’s Sierra Nevada beginning late spring and ending mid-fall, when early winter storms rather dramatically ended the 2004 Sierra hiking season. Trips were in mostly fair weather, with nighttime temperatures ranging from the mid-50s (14 C) down to the mid-20s (-5C). Camp elevations were between 7,000 and 9,500 ft (2,100 to 2,900 m). No rain (yay!). I slept in a one-man single-wall tent, under a tarp and in a bug bivy. My sleeping bags were a Mont-Bell Alpine Down Hugger #5 mummy and a Western Mountaineering Ultralight down mummy.

As with any air mattress, the key to comfort atop the BA Air Core is correct inflation, which involves some tweaking. Inflating the pad takes about a dozen breaths (taking my time at altitude to avoid becoming staggeringly dizzy). I like to inflate it upon arriving at camp to allow the insulation plenty of time to decompress. As evening arrives and the air temp drops, the mattress sags and requires more air before I go to bed. I over-inflate the pad so once in bed, all I have to do is release air stepwise until the pad is “just right.” The valve opens and closes smoothly to aid this process, but If I let too much out it’s then a wrestling match to get the pad out from under me, add air and slide it back underneath (I can’t inflate it while I’m on it). If I’m in my bivy, I have to actually evacuate to perform this feat.

I use a clothes-filled cloth sack as a pillow, placing it between pad and sleeping bag hood. The pillow can sometimes squirt out of place due to the slippery nylon of both the pad and sleeping bag. The pillow will stay put placed underneath the pad, but I’m not as comfortable when it’s there. The pad’s narrow foot end is fairly easy to slide off of. Fortunately, I’ve not found myself doing this often enough that I’d prefer a larger, heavier rectangular BA pad. The Air Core can slide on a silnylon tent floor, so it’s important to pick a level tent site to keep this from becoming a problem.

I generally start the night sleeping on my back, but inevitably roll onto my side later. If I’ve inflated the Air Core correctly, the pad keeps my hip, elbow and shoulder off the ground. I can’t recall losing circulation in my arm while side-sleeping—a common occurrence with my other pads. With the Air Core, there’s a fine line between too little and too much air. If it’s too full, the pad will be excessively springy when I’m on my back and if there’s too little, I’ll hit the ground when on my side. It just takes practice.

As noted in the summary, some nights prove too cold for the Air Core alone to keep me warm, so I need to add insulation atop the pad. Extra clothing will do in a pinch—a fleece jacket or vest is a good choice because it resists compression. If I know beforehand it’s going to get cold, I pack a torso-length quarter-inch (6 mm) foam pad that’s just long enough to extend from shoulder to rear. For a few ounces extra weight, I know I’ll sleep warmly.

Wear and Tear

The BA Air Core’s coated rip-stop exterior shows some minor scrapes. I didn’t use it as camp seating as I usually do a foam pad. Dirt clings to the black fabric (static charge) but wipes off easily. Sap, I let dry then scrub off or it becomes a smeared mess. Long-term inflation tests show the mattress slowly loses air over the course of a day or two, implying a very slow leak, but dunk tests don’t reveal where. It hasn’t been a problem overnight.

Conclusions

The Big Agnes Insulated Air Core mattress fulfills most of its considerable promise of supreme comfort plus warmth. The comfort is indeed great and as an added benefit, I have more sleeping spots to choose from because the mattress protects me from stony and root-bound ground that my other pads can’t. The Air Core’s shortcoming is its inability to keep me warm at temperatures well above Bag Agnes’ claimed 15 deg F (-9 C) minimum. Fortunately, I can supplement the insulation and still sleep well in cooler conditions.

The BA Air Core takes up less pack space than any other pad I own, meaning I can use a smaller pack. It’s fast to inflate and fast to deflate and pack away. It has worn well and I’ve experienced no punctures, failed seams or a fast-leaking valve (I still don’t know why it seems to lose air over time at home).

The three loose insulation batting strips I noted in the field report don’t appear to have loosened further, which is good news. Because they’ve not pulled away further, I believe they were loose initially. I recommend inspecting one in the store (by holding it, inflated, up to a bright light) before purchase to ensure the batts are correctly installed.

Rick’s bottom line: The Big Agnes Insulated Air Core Inflatable Sleeping Pad has earned a permanent spot in my gear vault.

Hits

Comfortable, easy to use and care for, small packed size and light weight.

Suggestions for Improvement

Consider a thicker insulation layer and non-slip fabric and offer a three-quarter-length version. Find a better way to attach the insulation.

Brief Backpacking Bio and Cold, Hard Ground Experience

When I joined the Boy Scouts, they neglected to tell me that some kind of mattress would be nice underneath my kapok sleeping bag. A couple of trips sleeping on the ground, wearing every stitch of clothing, including my boots--convinced me to look around and see what the comfortable kids were sleeping on. A-ha, air mattresses!

I got one, and still I froze, but the hard ground was far away, a definite improvement. I later learned the newspaper insulation trick and was a happy sleeper the rest of my Scouting career, as long as we weren’t actually backpacking.

As a freewheeling backpacker I first carried an air mattress, then a mattress and ensolite foam pad, then just the pad. The wooded Cascades and Olympics usually provided sleeping spots soft enough that an insulating pad was fine, plus I was a lot more…pliable then. The Therm-a-Rest came along after I’d switched to California’s Sierra Nevada where the elevations are manly and the rocks are too, and rock or dirt are what I normally sleep on.

My thanks to Big Agnes and BackpackGearTest for the opportunity to participate in the insulated Air Core Mummy Pad field test.

RTD 12.16.2004