2 car sun shades as sole sleeping mat in the late fall/winter?

[mmeiser]

So, I've now been using car sunshades, aka AutoShades for fall and winter camping for a couple years.

For reference I'm referring specifically to this:
http://www.bikepacking.net/reviews/sleeping-pads/car-sunshade-sleeping-pad/

They are absolutely superb for *supplement* insulation. I highly recommended them for their durability / indestructibility, light weight, ease of use and generally great r-value. What's more after a drought in which I could not find replacements I have realized they're now stocked at Meijer for about $7 or $8. What's more though auto shade designs will change I suspect they will be around for a long time to come.  Not that I'm taking any chances, I'm stockpiling them.

A typical favorite use example is that it is always the first thing out of my pack. Which is great because it needs no protection from the elements. It doesn't even hold water. Indeed I use it under my super twinkie seat bag sometimes to keep the mud off my *rse. You can even just wash it in a stream and be sleeping on it five minutes later.

But anyway, back to the point... used scenarios.

It's perfect for throwing down in the snow or on a wet bench or in the dirt to sit on to keep your butt warm and dry.

Indeed it's accordion fold design lends itself to a perfect sized sit mat every time.

They are especially great around the fire since they are very resilient to flame and even if you do burn some spark holes in them... hey.. they're only $5. You can afford to buy yourself a new one each trip.. not that you'll need too. 

In this respect they are the perfect compliment to an insulated air mat or DAM (down air mat) which are to delicate and take to long to deflate / inflate to be used and / abused in such a way... especially around a fire.

Another great use example is simply adding it underneath your bivy / insulated airmat / sleep system not just another thermal layer but also another layer of protection from abrasion and potential puncture.

You simply can't go wrong with them as a supplemental in the winter or even as a minimalist UL solo pad in the summer and early fall, but herein is the issue:

I'm seriously thinking of using TWO on the divide in mid/late October as my only sleeping mat and I will most likely encounter some snow.

Furthermore while I have one extensively as supplemental insulation for years I have never in all my use tried to use them in the snow by themselves as my sole sleeping mat.

AND... I have no way of testing them in the snow before I go.

So, the questions are:

1) does anyone have any experience with them in the snow as a solo sleep mat?

Again, I think two should have some serious r-value, but have no way of knowing.

2) does anyone know of any way to run my own r-value tests?

I have at least a basis for comparison since I own several mats including a Big Agnes primaloft insulated Aircore, a Thermarest Z-rest, and an Exped Airmat.

I do have fairly extensive winter experience with these sleeping mats here in Michigan. By "fairly extensive" I mean, the newest one and one I've used the least, the Big Agness Primaloft Insulated Aircore I used for 25+ nights on my 30+ day January trip down the eastern divide last winter both in snow and in temps well below zero.

Indeed it is the three time failure of this Big Agness Aircore mat that was the biggest issue on that trip. Pretty much the only issue in an otherwise great trip. It failed near the valve stem, probably due my sliding in and out over the valve stem when entering my bivy.  The worst part was not the three restless and cold nights, but that it destroyed my confidence in being able to camp at altitude causing me to have to completely change my hard charging, late riding, always remote camping, trip dynamic. Specifically I couldn't ride late into the evening, night ride over passes, ended up staying in a lot more hotels and retreated from at least one storm on the BRP (Blue Ridge Parkway) to the valley because I couldn't be sure of getting a good nights sleep. 

I finally succeeded in sealing the holes (multiple pin holes at the corners of the valve seam) well and restoring my faith in it with some Shoe Goo, but by then the trip was pretty much over and the damage done.

Unfortunately I'd opted not to take an car sunshade on that trip.

I really wish I had. 

I do love the Aircore, its thermal properties are superb and quality high but it is absolutely not for bivying and I really wish I could take my Exped Airmat's huge and indestructible valves that make it so easy to blow up and put them on the aircore. Indeed... I'll probably at some point get an Exped 7 XS weighing in at 21.9 oz.

But back on point. It is because of that trip I've decided that while I love air mats because when they work they work extremely well... that they're to high maintenance (inflating / deflating / patching) and too delicate for longer trips, i.e. more then s24o, 48, 72 or at max week long trips.  Not that I won't use them in the future for specific conditions (I love my Exped and in 2-3 three years heavy use its never failed me) but I don't want to rely on them for longer trips again.

Thus we come back to the autoshade. 

Extremely light. (5oz before trimming down)

Fast packing.

Fast unpacking.

Relatively compact packing.

Foolproof.

Bombproof.

Durable.

Easily washable.

Easily dryable.

Extremely inexpensive.

Layerable.

Great as a supplemental.

Like so many of my favorite pieces of UL bikepacking gear (i.e. alcohol stoves) they seem to cheat the rules of expensive specialty gear and high dollar materials.

...but what is its R-value???

[mmeiser]

Further thoughts.

Last winter I ran insulative tests to find out the best way to keep my water from freezing for riding in extended cold.

On that trip I used a huge 48oz nalgene as my primary water and two 1L platypus bladders to supplement.

My primary objective was to find a way to insulate the nalgene.

I ended up brainstorming up and then testing three different ideas.

1) Smartwool sock cozy / double layer cozy in a water / wind proof dry bag.

2) Reflectix cozy

3) rolling it up in my deflated Big Agness Insulated Airmat* and putting it in an wind / waterproof drybag.

I tested these by putting three nalagene filled with room temp water in respective cozy's and placing them in the freezer.

After only three hours the water in the Reflectix and smartwool insulated cozys had already frozen or mostly frozen but it took about 18 hours for the Big Agnes insulated nalgene to develop any serious ice.

I used this Big Agnes insulation technique on my 30+ day january trip and didn't even have a single issue with freezing water or even icy water despite sometimes having daily highs of 14F.  The best part wasn't how easy it was to slide the bottle in/out of the cozy but that the entire setup didn't require me to take even an extra ounce of gear since I was repurposing my sleeping mat and a couple of Smartwool socks I sleep in.

What I'm hoping is I can come up with as difinitive a test for the Auto shade airmats.

Hmmm...

Perhaps I should simply roll an autoshade airmats around a nalgene*, put it in a dry bag and stick it in the freezer??

Could it be so simple?

*I should be clear... when I tested/used the Big Agness airmat as a nalgene cozy I stuffed a spare smartwool sock in the bottom of the dry bag and one more in the top to protect the top and bottom of the nalgene from freezing. It's a very important detail. BTW, these were my spare pair of dry and clean "sleep socks" since one should absolutely not sleep in their damp/wet riding socks at night in the winter.

[JayP]

wow mike! thats a lot of info for someone who never has experinced or is new to packing, lucky them.

i will be much simpler with my response in regards to car shades. i hit up my heating/plumber friends for there water heater insulation wrap or you can go buy a roll, sort of spendy but it is a big roll and it will last you a long time. similiar to car shade but better. if you google research it you will find it to have the highest R-value rating in comparison to any sleeping pad. it's the only pad i have ever used in the winter and the past 5 years at the Ultra Sport. i have brought 2 before but 1 cut to the correct size is fine. in the winter cut it big to surround you when you sink into the snow. summer time i am a spoiled air mattress sleeper, sleep is king when comfortable!

cheers.

[mmeiser]

i hit up my heating/plumber friends for there water heater insulation wrap or you can go buy a roll, sort of spendy but it is a big roll and it will last you a long time. similiar to car shade but better. if you google research it you will find it to have the highest R-value rating in comparison to any sleeping pad. it's the only pad i have ever used in the winter and the past 5 years at the Ultra Sport. i have brought 2 before but 1 cut to the correct size is fine.

At first I thought you were talking Reflectix, but after a little research I think I understand what you're talking about.

I wonder if it matters what brand?

Thermwell Products SP57-11C Water Heater Blanket R10
http://www.google.com/products/catalog?q=water+heater+insulation&hl=en&safe=off&prmd=ivns&um=1&ie=UTF-8&tbm=shop&cid=10447340454055928758&sa=X&ei=ixlFTpn-J_H_sQLt-OWSCA&ved=0CH0QgggwAQ

I assume that R10 is an R10 rating... which is insane... BUT... it's not meant to be compressed.

This is some serious stuff for extreme winter insulation. Probably to much insulation for this trip... but then again I could just make a torso pad to supplement another lighter sleeping pad.

[sean salach]

Pretty sure Jay was talking about reflectix. It's got an R value of somewhere between 2-5 in our application. It requires an air space between the heat source(your body), cold source(ground/snow) and the reflective surface in order to offer much for insulation. A sleeping bag with lots of loft will provide a large amounnt of the air space needed, except under the pressure points. Spruce boughs will help a lot underneath. The main downside I've found is that it's slippery, so unless it's wide enough and positioned correctly, I'm more likely to find the foot of my sleeping bag in the snow than I am with a Z-rest or Ridgerest.

[bama]

In December 2011, I slept on frozen ground on the Edge Loop, above Fruita, Colorado. It was a mildly windy ridge with a little snow, but the ground was definitely frozen solid. Temps dropped to somewhere around 5F. I had a RayWay blanket with 2 layers of insulation, fleece pants, and slept in a Montbell synthetically insulated jacket. I used my handlebar pogies to keep my feet warm, and kept water in a Klean Kanteen so I could melt it over the fire in the morning.

For a ground pad, I used a 4' roll of Reflectix foil-bubblewrap found at Home Depot. I folded it in half, so it was effectively two layers of 2' wide insulation. I packed it like an accordion, and it took up a lot of handlebar space.

Results: It was plenty warm enough! The R-values vary depending on how it's used, but two layers would probably be a minimum of R6. I think one 4' layer of Reflectix would've been sufficient, but definitely put the pogies on your feet! They're really nice sleeping socks!

Reflectix pros: super warm, cheap, light, comfy

Cons: very large pack size

note: check out my RayWay tarp-tent; the ground was too frozen for stakes, but when I went to use rocks, most of the rocks were frozen from frost-heaving.. geeze.

[Colorado Cool Breeze]

In winter camping I've used a large piece of tyvek(4'x7.5') as a ground sheet on snow
and placed my pad, Reflectix trimmed full length to fit the mummy shape, in the sleeping bag to keep it in place.
 
To keep my nalgene water from freezing over night, one of my spare winter socks with chemical hand warmer pack.
If I'm really worried the bottle comes in the sleeping bag with me.

[mmeiser]

@colorado cool breeze... you should fill that nalgene with boiling water from the fire / stove and put it in your sleeping bag before you go to be... not only won't it freeze but it'll keep you warm all night.

BTW, just got back from the Allegheny mountains area. About 500 miles in eight days.  Some snow and plenty of cold temps. Often dipping into the 20's and even 10's overnight.

http://www.flickr.com/photos/mmeiser2/sets/72157632171791809/

As a sleeping pad I took two autoshade window shades.  I upped it to three stopping into a NAPA Autoparts store in a small town.  Three seemed to work well. No cold spots, but there was some snow melt underneath.   My only issue was a small one of bulk when packing but mostly in the flimseyness(sp?) of the autoshades within my quilt system.  I pretty much solved it by tapering the foot of the mats with folds.  I think a safty pin or two would have completed the trick.  It gave them extra thickness in the foot and stiffened them up so they could be more easily be directed into the foot of the bag and didn't scrunch when I tried to slide in on top of them.

Yes btw, I did sleep directly on top of them. Sometimes just a merino wool pant between me and them, sometimes experimenting with wearing more layers. BTW, I always wear my down coat up top. The hood on it works well with the quilt system.

BTW... If there's one thing I've learned it's how damning being a side sleeper is in the cold. It creates cold spots / preasure points on the hips and sholders both underneath and on top. Best just to learn to sleep on ones back.

[Colorado Cool Breeze]

@colorado cool breeze... you should fill that nalgene with boiling water from the fire / stove and put it in your sleeping bag before you go to be... not only won't it freeze but it'll keep you warm all night.

BTW, just got back from the Allegheny mountains area. About 500 miles in eight days.  Some snow and plenty of cold temps. Often dipping into the 20's and even 10's overnight.

http://www.flickr.com/photos/mmeiser2/sets/72157632171791809/

As a sleeping pad I took two autoshade window shades.  I upped it to three stopping into a NAPA Autoparts store in a small town.  Three seemed to work well. No cold spots, but there was some snow melt underneath.   My only issue was a small one of bulk when packing but mostly in the flimseyness(sp?) of the autoshades within my quilt system.  I pretty much solved it by tapering the foot of the mats with folds.  I think a safty pin or two would have completed the trick.  It gave them extra thickness in the foot and stiffened them up so they could be more easily be directed into the foot of the bag and didn't scrunch when I tried to slide in on top of them.

Yes btw, I did sleep directly on top of them. Sometimes just a merino wool pant between me and them, sometimes experimenting with wearing more layers. BTW, I always wear my down coat up top. The hood on it works well with the quilt system.

BTW... If there's one thing I've learned it's how damning being a side sleeper is in the cold. It creates cold spots / preasure points on the hips and sholders both underneath and on top. Best just to learn to sleep on ones back.

I read about the hot water bottle in the SB trick but have not tried it yet. Sounds toasty.
To keep my pads from moving out from under me, unlevel areas,  I've put them in the SB at times.
But if I can find two trees I'm a hammock hanger at heart and prefer it even in winter.