REI Minimalist Bivy and MSR E-Wing Tarp combo test

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REI Minimalist Bivy and MSR E-Wing Tarp combo test

Post by Hetchy » Sun Mar 01, 2009 5:57 pm

This is a two week long test of the REI Minimalist Bivy Sack used in conjunction with a Mountain Safety Research E-Wing tarp. I am shaking up ALL of my preconcieved notions of backpacking in advance of my PCT hike so I am in a quest for the "Silver Bullet" of shelter systems.. or as close as I can get :)
Fortunately nature has provided me with plenty of rain and some wind up here in the Santa Cruz Mountains. In fact 13 inches of rain cumulative and 30 mph winds with gusts to 50 mph(during storms). I have been sleeping in the yard at the ranch to test out my gear for an upcomming thru-hike of the PCT and thought I would share some findings with y'all.
The REI Minimalist bivy at 1lb 1 oz and the MSR E-Wing at 6 oz are the total shelter system for this test. I tested them along side my Eureka Solitaire which was left standing next to and unoccupied as a water tightness test (as well as a Chouinard Pyramid and a now defunct Sierra Designs Divine Light).
This REI minimalist bivy is definitely water tight from below the mesh face opening down. Though there was always some "minor" condensation on the inside each morning. I always was sure to breath through the mesh, and not into the sleeping bag, about (guessing here) an ounce of water was present each morning around the interior of the bivy. Though my Western Mountaineering Ultralight never felt clammy, I did air the bag about every other day but at no point brought it into the house or otherwise removed it from the bivy sack(I wanted to see what would happen with regular use). The temperature was,on average 48 degrees during the nights and I was able to leave the zippers half open on both the bag and bivy. Overall I found the Minimalist Bivy to be very handy at both increasing the temperature rating of the bag, protecting from wind/drafts, and totally water proof from rain that hit the footbox(see below regarding tarp coverage). Though I did find it neccesary to wear a Columbia Kazoo hat with a bill when testing the bivy totally enclosed because the mesh would otherwise sag touch my nose and cause discomfort. I could not test the bivy totally closed for long as I began to overheat and always found the need to leave it half zipped(mesh rolled back).
The MSR E-Wing Tarp. This Tarp weighs 6 ounces. Has eight guyout points, and is made of silicone coated nylon. It can be setup in multiple configurations useing trekking poles though I found it most useful in a simple "PUP" tent or A-frame configuration.
I staked out the four sides to the ground 6 feet apart and ran a piece of parachute cord through the four guyouts in the middle of the tarp then through the straps of my upright trekking poles and then to stakes about three feet away from each end. I further added a plastic hook and prusik knot to each end near the treeking poles(uprights) to bring the tarp in tension along the main guyline. I ended up with a pup-tent 6' wide by 23" high by 8' long(peak to peak). The configurations are endless and caternary layouts are possible as well. But I setteled on this simple arangement for the duration of the test.
Despite the E-wings seemingly unsealed stiching, it has yet to leak after 13 inches of rainfall upon it. I must say that the quality of this tarp is excellant. The material is unlike any other silnylon I have used. Of course the tautness of the pitch is paramount and some stretch is exibited when it gets wet, but this is typical to all silnylons. This tarp simply refused to flap. It bows in the wind but at least in this configuration it never flapped once.
There was just enough room beneath it to both cover the open face of the REI bivy and keep my pack dry even with rain blown wind. Though I had to expose the footbox of the Bivy to the elements to achieve this. Seemed strange to feel rain hitting me at first but since none got in through the bivy, it did not hurt, and I got used to it.
The beauty of this setup is the total lack of claustrophobia, unlimited ventilation, ability to stargaze, yet maintain protection, at a whim by sliding a few inches, and the simplicity of setup using trekking poles I already carry.. did I mention the whole shebang weighs 1lb 10ounces(Bivy Sack,Tarp,Stakes,Parachute cord).
For bug protection I nabbed a US Army Skeeter Tent from the Surplus store and found that by inverting the tarp over the top main guyline I could simply hang the skeeter tent of the main line and weight it down at the edges with stones. Though I have yet to use this bug rig in any kind of wind.. (kinda figure the wind will obviate the need anyway).
At least for now I am a tentaive believer in this new (new to me) system. The versatility is attractive, though I would not want to layover through a multiday snowstorm this way, I know it is viable in multiday rainstorms. I will let you know as testing continues. At this moment I believe I have a versatile winner or at the least a runner up. :) Cheers, Hetchy

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Re: REI Minimalist Bivy and MSR E-Wing Tarp combo test

Post by JosiahSpurr » Thu Oct 15, 2020 11:53 pm

Hetchy wrote:
Sun Mar 01, 2009 5:57 pm
[.....] so I am in a quest for the "Silver Bullet" of shelter systems.. or as close as I can get :)
How did that combo do for you on PCT? one pound, ten ounces sounds really good.

I just purchased a 55" by 12 foot roll of neoprene, for the purpose of hand-sewing a bivy (or bivvy, or bivi, or bivvi...). The material is a closed cell foam, should be good for rain protection and heat loss during winter.

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Re: REI Minimalist Bivy and MSR E-Wing Tarp combo test

Post by austex » Fri Oct 16, 2020 6:26 am

Hetchy hasn't been active since 2012; hope you get an answer.

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Re: REI Minimalist Bivy and MSR E-Wing Tarp combo test

Post by maverick » Fri Oct 16, 2020 8:34 am

Hi Josiah,

Click on his name and do a search thru his posts using the search feature, just type in PCT and you will get plenty of info. ;)
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I don't give out specific route information, my belief is that it takes away from the whole adventure spirit of a trip, if you need every inch planned out, you'll have to get that from someone else.

Have a safer backcountry experience by using the HST ReConn Form 2.0, named after Larry Conn, a HST member:

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Re: REI Minimalist Bivy and MSR E-Wing Tarp combo test

Post by Wandering Daisy » Fri Oct 16, 2020 11:17 am

A lot of light weight shelter systems have come out since the original post. There are many solo tents now at 2 pounds, some at little over 1 pound if trekking poles are used and if you have $$$ for the new light fabrics. The 1lb/10oz tarp-and-bivy combination described above is only a few ounces lighter. I have used a 1lb 4oz mountaineering quality bivy for long trips in the past, without a tarp. At the time it was a good weight savings over a 3-4 pound tent. Now, I have a 2 pound (including 10 stakes) tarp-tent that sets up on trekking poles. I still could use my old bivy on an overnight trip, with no bugs, but my pack is already light on short trips, so it hardly makes sense. The only reason to do this is that the bivy is more compact which allows me to do an overnight with my day-pack. I feel that the tarp-bivy system is no longer that valuable unless you plan to camp in extremely tight spots or up on a mountain ledge.

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