Sleep system question

What about Enlightened Equipment booties?

I’ve always thought of the uberlite as a good 2+ season pad, the Xlite as a 3 season pad and the Xtherm as a 4 season pad.

When I look at pads my strategy is to find one thats comfortable, lightweight, and use on the majority of my adventures. In that order.  I’d prefer not to have a collection of pads, currently I have my goto which is an insulated 3.5R value Sea to Summit. Its not the lightest in its category at 21oz, but I enjoy the comfort and for me thats more important than the lightest setup possible. I’ve dialed in my base weight, its my luxury item. It does get a little steamy in the summer, but I have a gameplan for those nights.  I do have the Gossamer Gear thinlite, but honestly its not a great addition.

All in all a sleeping pad is a personal choice based on your preference, and budget.

I sleep on an X-therm year round.  It’s R-6 give or take with the new ratings and your mattress at home is much higher – mine is 14” of foam so at least R-30 or so.  The point is, don’t get hung up on summer pad, winter pad, fringe season pad.  I used to but have found that the “winter” pad works well all year long and doesn’t need another pad to augment the warmth when it’s cold or to protect the fragile bottom – especially the Uberlite.

My sleeping system consist of a GG thinlite pad, a NeoAir Xlite , Cocoon Microfiber Mummy Liner, and my Zpack 20deg classic sleeping bag.  I use this system almost all year round unless temps get extremely cold then I switch out to my 0deg Mummy bag.  I lay the GG thinlite pad down first in my tent to keep my Xlite from moving all around the tent floor.  This also adds a little buffer from the cold ground as well as a little added protetion to the bottom of the Xlite pad.  I then actually take my Xlite pad and slide it inside my Cocoon liner so it acts like a fitted sheet.  It feels so much better laying on a soft, comfy microfiber sheet then the Xlite pad material and it adds some warmth.  I then use my Zpack classic sleeping bag which has a 3/4th length zipper on the bottom, combining the best aspects of a down quilt and a down sleeping bag.  I mostly use it as a quilt but can zip it up if I want to use it more like a sleeping bag.  This makes a great warm, versatile, light weight sleeping system for me.

I own an Uberlite, but maybe get a half dozen nights of use out of it a year; my Xtherm on the other hand is used a bunch!

Outside of dead of winter, I use it alone- winter I’ll add a ccf pad.

I used to own a couple of Xlites (Neoairs), sold them after the small difference in weight between them and the Xtherm.  If I sold the Uberlite tomorrow, probably wouldn’t miss it much either.

You say: “I noticed that it took quite a while to warm up on the bottom.” The statement implies that once it warmed up, it stayed warm (enough?).

Try adding the GG thinlite but I would think if the R value of the current pad was not sufficient, you would experience the heat loss through conduction at an increasing rate as the temperature of the earth beneath cools to its lowest point, say a couple of hours before sunrise. And once that process starts, you never get warm unless you add layers underneath your pad. First I use my sit pad, then my pack, etc, etc..

I wonder if you are losing heat through radiation around the bottom edge of the quilt.

The other thing I have found with an older Neoair is that as I moved in the night, the pad got colder since I was losing heat out the 2 inch high edges of the pad. I think in the last two years or so Cascade Designs changed the baffling to mitigate this effect.

Also I would guess that sleeping on top of wet grass will be colder than sleeping on dirt or mulch in your backyard. Let us know how the experiments go.

Let’s run some numbers from manufacturer’s web sites and see what happens:

Weights
8.8 oz – Uberlite Regular
2.5 oz – GG Thinlite 1/8” (Listed 2 to 3 oz, splitting the difference)
-2.0 oz – Leave Z Seat at home
9.3 oz – Total

15 oz – Xtherm regular

R-values
2.3 – Uberlite Regular
0.5 – GG Thinlite 1/8” ((GG estimate based on similar foam)
2.8 – Total

6.9 – Xtherm regular

For an extra 5.7 ounces you go from R 2.8 to R 6.9.

But sleeping bag and quilt EN or ISO temperature ratings are based on an R 4.8 sleeping pad.

And you were already struggling to stay warm with an R 4.2 XLite in the low 30s F.

According to REI’s own research, a pad between R 2.0 and R 3.9 might add about 12 degrees F to your quilt’s temperature rating. Meaning your Magma 30 quilt (which has vanished from REI’s web site), might have an effective EN/ISO “lower limit” rating of 42 degrees F, when used with the Uberlite/Thinlite combo.

Plus, the EN/ISO “lower limit” bag/quilt rating is sketchy for most people, unless they are willing to wear a puffy to bed and camp in sheltered locations. With a pretty warm head covering for quilt users.

I’d think long and hard about keeping and using the Xtherm year-round, as others have suggested. OTOH, you could layer the XLite with the Thinlite, hit R 4.7 (close enough) and net gain about 0.5 oz.

Your choice.

— Rex

More information:

Sleeping pad R-values: Not that useful, BPL
https://backpackinglight.com/sleeping-pad-r-value-not-that-useful/

Improving R-Values for Consumers, BPL
https://backpackinglight.com/improving-r-values-for-consumers/

Sleeping bag temperature ratings (video podcast), BPL
https://backpackinglight.com/forums/topic/unlimited-podcast-002-sleeping-bag-temperature-ratings/

Thanks for the input. I think I’ll keep the xtherm as others have suggested. I’ve been trying to cut my base weight, but I don’t want to be stupid about it.

I use an older 66″ length (no longer offered) x-therm year round. At 14oz it is only 2-3 ounces heavier than the 66″ x-lite but has a much higher r-value and if memory serves correctly a more durable bottom.