v-g Backpacking in Britain Blog

Time to add my own report on the new ultralight NeoAir mattress, another field trial to add to the collection that recently appeared in the blogosphere and online forums. We bought one for each of us from Bob at BackpackingLight, giving the opportunity to test both NeoAirs over the course of four backpacks and several nights.

The launch of the NeoAirs caused much excitement and anticipation but also some raised eyebrows: here we have essentially an ultralight ultra-compact version of the common ‘lilo’ airbed. Unlike the self-inflating Thermarests such as our ProLites which are foam with a (relatively) small amount of air for inflation, these are entirely air, and there are disparate reports about their ability to maintain that inflation. Most backpackers have been very pleased with them, but for a few there is a case to answer.

First of all we must be reasonably clear about expectations. As the Thermarest leaflet correctly points out:-

…Be aware that barometric pressure and significant changes in temperature will affect the inflation…with a significant change in weather your mattress could also lose some pressure. This is natural and does not necessarily mean that you’e developed a leak…

In other words, with this type of mattress a certain amount of deflation is inevitable, especially when temperatures differ greatly between day and night, but how much is within tolerance before the sample is deemed faulty?. When we first unpacked the NeoAirs I tied a little piece of cord to one of their stuffsacks to distinguish them during their trial period, and in my tests the result appears clear: one is fine, the other is not.

On my solo Lower Eskdale backpack I took one at random and it performed very well, the small deflation being well within expectation and actually a welcome benefit: a fully inflated NeoAir can feel a bit hard after a while. At no time did I need to blow more air into it.

The North Berwyn backpack was a joint trip: Vivien used the one that performed well last time and I used the new untested one. Hers behaved very well again and never required more air, but mine was soon suffering: I woke up after a couple of hours and the mattress felt a bit flabby. At first I couldn’t really say if the deflation was entirely due to temperature and pressure changes, but I put a couple of puffs of air in to reinflate it and settled down again. By morning the difference between mine and hers was very striking: mine was badly deflated with my shoulder and hip touching the ground but hers was fine.

On my solo Central Cairngorms backpack I took the good one, I didn’t want to invite problems on a trip of 5 days. That NeoAir again performed very well throughout.

The last test was my solo North Western Carneddau backpack, a short 2-dayer, and I took the suspect NeoAir. Same result as before, it deflated quite badly twice during the night and required significant reinflation each time. In the morning I fully inflated the NeoAir and lay forwards on it to squeeze the valve end in an attempt to feel or hear any leaks in that area, but no success.

Robin (Fenlander) also has experience of two NeoAirs and reports exactly the same phenomenon. He tried a much better submersion test on his badly deflating NeoAir but detected no leaks either from the seams or valve: a curious result but there it is.

The strikingly obvious difference in the deflation of our NeoAirs makes the conclusion clear for our case also: one performs superbly and I’m really pleased with it, but the other is plainly not right.