Best of both worlds (weird pad combo)

We do the same…but just because we’re old.  A Zrest goes on the bottom, then a Neo-Air on top.  We started this when we were doing a series of trips and the Neo-Airs were losing air overnight.  That was no fun, so we grabbed a Zrest and lashed it on the top of our packs.  Now we do this all the time.  More comfortable, warmer, and less than pound of extra weight…

Since I usually carry about 30 pounds all up, and my wife in the low 20’s this seems like a good use of the weight for us.

Were they losing air, or more so temperature changes causing pressure changes?

When i blow up my Neo air at night using an air pump, it doesn’t seem to deflate that much, but when i blow it up by mouth, especially when it’s day (and generally warmer out), the pad deflates noticeably by late night/early morning.

I figure a good percentage of folks probably use a combo of foam and inflatable pads, especially in winter time or during colder trips, but i’ve never heard of anyone using the first specific combo, so i’d thought i mention it for the UL’ters and SUL’ters who want a little more comfort at not much weight.

“Were they losing air, or more so temperature changes causing pressure changes?”
We’ve been debating that for three years.  Still no definitive answer !  :^)

Mine does it… sometimes…

I dont get it.  Maybe sometimes the valve doesn’t seat right?  I will blow my pad up early in the night.  Top it off before bed.  And sometime blow it up at night.  It seems the colder the temp, the more I have to do it.  Other times it holds tight all night, no problem.

Hey justin – what’s the weight of that combo?

Jeffs has described the problem quite accurately: the colder the temp, the more I have to do it. 

If you use your lungs to blow up an air mat, you are blowing warm air into the mat to get pressure. As the air in the mat cools, the air contracts and the pressure drops. The colder the ambient, the more it cools. Using a pump means starting with much colder air, so the effect is much less.

I will add that blowing a mat up using your lungs means you are injecting a lot of moisture into your mat. It will condense, and after a while you will have enough water in there for a goldfish bowl. A really bad idea. Chuckle: if it is really cold, you could even get ice inside your air mat!

I use the Exped pillow/pump. No moisture in the mat, and a nice pillow for the night.

Cheers

Good question Jen.  Answer is, i don’t know off the top of my head. It’s been awhile since i’ve weighed something.

But i will weigh it all and get back to you.  I made a mistake earlier, i do not have the X Lite version of the Inertia, i have the regular X frame version which is about 4 oz heavier according to online specs. Kind of wished i had the X Lite version since the other one is too long for me anyways.

Btw, i’ve read some complaints about the above models as to air leaking out of the pump nozzle area, but i haven’t had a problem with that yet.

Jen, i weighed the pads.  I weighed the 1/4 and 1/8 Evazote foam pads together, and they come out to 14.9 oz.  The 1/8 pad is really big though, very wide and pretty long.  I like it because my arms tend to come off both the air and 1/4 Evazote pads and so i have something to give a little insulation and cushion to them when they do.

The Klymit Inertia X frame pad weighs in at 9.2 oz according to my scale.  So for a total of 24.1 oz, or almost exactly a pound and a half.

If a person used the Klymit Inertia X Lite pad, the weight would drop around another 4 oz’s or so. (I would prefer to have the X Lite pad myself, since i’m short with a short torso).

The main advantage of this system is compared to a warmer at lighter or similar weight say Neo air type pad, if something happens to the inflatable pad in the field, and the hole, cut, nozzle leak or whatever is beyond repairing in the field, unlike the Neoair pad, you’ve still got usable and reliable ground insulation.  Here the inflatable is used less for warmth, and more for comfort.

The reason why i put the wider/longer piece of the 1/8th Evazote foam on top of the Inertia X frame pad, is to help still the air that is in the “loft pockets” more than it would be if i slept directly on top of the X frame pad.  Using a sleeping bag instead of a quilt, would boost the insulation even more.

The 1/8th pad is large enough that i can wrap the K.I.X.F. pad in it like a burrito (well, more like a taco), but sleeping on it proves to be more finicky as far as the 1/8 pad moving around and off the air pad. It’s easier and more stable to just throw it on top and have some side material hanging off, which i like for my arms anyways, as mentioned earlier.

I’ve done the same for a while. I’ve been using a GG Thinlite under a torso-sized Thermarest Proite. The Thinlite is huge, full length 72 inches, so it is in essence my groundsheet.