State of the Market Report: Bivy Sack Technologies, Products, and Applications (2006)

[Benjamin Smith]

Companion forum thread to:

State of the Market Report: Bivy Sack Technologies, Products, and Applications (2006)

[eric levine]

The obvious solution for inner winter condensation problems (i.e., Epic and other bags) is to use a vapor barrier, either worn as clothes or a liner. That new improved space blanket bag sold at this site could be just the ticket.

VP isn't just for below zero. I believe at the 15-20 deg F. range a VB will work reasonably well for most folks, and I believe it can work up to 30 deg. F. for more folks than many think. Give it a try.

[Edward Silva]

Hmmm…

Ryan Jordan said the Integral Designs South Col eVent has a bug net, rating it a 4 for insect resistance.

But the Integral Designs website says it has no bug net:
http://www.integraldesigns.com/product_detail.cfm?id=693&CFID=8419389&CFTOKEN=95048248&mainproducttypeid=1

What's going on? Confusing…

[paul johnson]

I may have as many bivies as DrJ??? Some are the same ones he has (e.g. eVENT Uni and Lightsabre), but perhaps some he doesn't have (not counting two custom-made with special modifications per my specs by WT and MLD).

Right or wrong – i make a distinction b/t bivy sacks and bivy shelters – it's the hoop which is not to be confused with a stiffening wire which some bivy sacks have. Also, some bivy shelters may require at least one stake to give the hooped/domed head end the proper shape, but wire stiffened bivy sacks don't (at least the ones i'm familiar with).
Loved the review article. Much of it struck a responsive chord in me.

Only qualifying remark i might make is regarding the ID eVENT Uni. Not enough bug netting for summer use in hot, humid, buggy New England. If no bugs, could unzip it, but if it needs to be zipped up, it's bug netting is only "window" sized" (i.e., NOT as small as a "porthole" bug net opening, but also a far cry fr/unzipping down to the waist and having bug netting still protecting you).

Bivy sacks/shelters can make trail life so simple.

Other potential downsides, for those not familiar with using a bivy as a standalone shelter, is no vestibule to cook under or melt snow under, and rain entry during bivy ingress/egress. If need be, one's poncho or natural cover can help ameliorate the lack of a vestibule, though the pitching of a poncho removes some of the simplicity from the equation.

One neat thing about some bivy sacks (ID Salathe, for example) is that they have six sliders which allow for creating arm openings so that one sit up and can cook breakfast, enjoy a hot drink, and still remain nice and ensconced in one's bag *AND* shelter.

Some MLD bivies can also double as wearable back-up rain gear!

[b d]

The weight is what is important to me in considering the bivy sack as gear I will really get out there and use. The BMW/BPL Nano looks like it will be in my gear to try out (when they are available) – 3.5 oz as I recall.

I bought an OR bivy in about 1992. It is great, but heavy (as I recall 1.5 lbs. or more), has the bug net, hoop pole to keep the head area open and doesn't breathe much. Can be sealed/zipped up for inclement weather. Cost a lot then, too.

Never ended up using the old OR bivy much because of tent camping for two being the thing to do. Given the weight of the older OR bivy, two of them would be more than or near the same as a light tent shelter system with floor and mesh. I think the old OR was made of an early form of GoreTex type lined fabric, not coated or saturated with a water resistant or water proof chemical. But the concept is so enticing I kept the old OR bivvy and threaten myself I'm going to use it just for the conceptual pleasure of being in a self-contained shelter unit which keeps out wind, cold, rain, snow, bugs, etc. (I am not really into hammocks, since finding trees to tie them to seems tricky and I never slept well in a hammock but people who love them love them.)

Presently I use the UL Tarptent(s) or a MH free standing mesh body in good weather (around 1.5 – 2.5 total lbs for a two person shelter system), but the bivy thing is calling me given the UL weight ranges of 3.5 oz. – 7 oz. weights for the BMW bivies.

I think the different contemporary Integral Design bivies look great, and they got RJs use/approval, but the weight is a factor, since they can weigh about as much as a TT or SMD tent w/ floor and mesh.

I want to try the Nano out as a groundcloth substitute and stand alone shelter/bivy in better weather. Sounds great and a real pack weight reducer … or maybe even use it with a tarp in rainy weather, although it is going to take building up my confidence in the tarp-bivy system and the ability to pitch a tarp taut in different configurations for different wind and weather.

This State of the Market report on bivies is great reading and thought provoking re: what am I gonna do next year.

[Phil Barton]

Great article, Ryan. My first effort in bivy camping has been with the Equinox Ultralight Mummy Bivy in combo with a poncho/tarp. So far, I like the MLD poncho a lot. I think that you captured the essence of the Equninox bivy very well. It is extremely light and simple. However, it isn't large. I would like to experiment with another bivy that didn't compress my loftier bag during cool weather. The Equinox achieves a light weight in part by using very little material. It's girth is pretty slim compared to mine. I'm 6' and about 205#. I could use both some extra length and width to really be able to close the bivy and not compress my sleep system.

For the next iteration (I'm always trying another iteration of packing, sleep, and shelter) I'll probably look at Oware, BMW, and MLD. Ron at MLD has some very cool ideas and is willing to customize his products for a bit of extra size where needed.

Your article causes me to wonder if I might find use for a storm resistant bivy. The weight optimization is very intriguing. But I really enjoy being able to hide out under a tarp when making camp, enjoying the views, cooking, or just organizing stuff. We'll see.

Thanks for another thoughtful review.

[Denis Hazlewood]

Great article. This should really help the curious make better gear decisions.
I've been using a Bivy on and off for 20 years. My first was an REI Cyclops with matching lightweight bag. I've also used mummy bags with good success. I have had some condensation problems, especially around the foot. I've spent a couple of rainy nights in it and was fortunate to be using a synthetic bag at the time. I still have it. I've tried to sell it to no avail. I had an O.R. Advanced Bivy for a while. It has several good freatures but the removable pole ends are a real bother when you are being rushed by that black cloud approaching. My favorite is the ID eVENT Unishelter. I'm 5'8" and use a NF Beeline and there is plenty of room for 4 LuxuryLite cylinders stacked around my head. I leave my boots outside, under a plastic bag. I only use bivies when I expect only a chance of rain. If I add a small tarp I will extend hte Uni's range at a very small weight increase.
I was pleased to see the Uni place so high.

[paul johnson]

Denis, here's what i do w/the OR Advanced bivy. I leave the pole ends snapped in place when i fold and roll the bivy for packing. as i fold and roll, only one or two repositionings of the still attached ends to get them oriented properly is all it takes. IMHO, this eases set up at the next bivouac.

[Hajime Kawasaki]

Great article. I am much interested in the new fabric of Itochu. The report of OR show said this new fabric is as breathable as eVent.(on Labo data)
But, the rating of condensation resistence of GoGo is 3.
Is this GoGo is older verion (yellow) ?

[Sam Haraldson]

We have a copy of the factory tests on all the Nemo fabrics at our gear shop if anyone wants really specific data (waterproof, abrasion, vaporproof, et al).

[Ryan Jordan]

Glad to see other Unishelter users out there.

Paul, I'd have to argue with you on its warm weather performance. It's just fine, with plenty of ventilation for temps on up to the 40s. Oh, wait, you mean the NEW ENGLAND definition of warm. Ohhhhhh…Yeah, ick.

For the 31 oz of a Uni, I could take a Squall, or Lunar Solo, or a Hex, etc. So, "what the heck?" you say is all the fuss about.

It's purely aesthetic for me. The concept of a bivy is soooo simple. Have you tried to set up a Hex on a narrow ridge with views spilling down both sides to massive mountain valleys? And the Uni appeals to me because I can sit up and cook while remaining in my bag if the weather is dry, but I can cocoon inside it and enjoy the very real few degrees of extra warmth and wind protection it provides over an open tarp.

Bivy camping is just plain fun.

I like the GoGo as well, it's a great bivy for stormy conditions, with its end opening, being one of the few that you can cook while inside the bivy and protected. But the wriggle factor required for entry and exit is real.

[Greyson Howard]

So do you all sleep with the pad in the bivy or out?
I like the idea of having everything contained in the bivy for moisture and keeping everything in place, but with my REI bivy I feel pretty confined, like a patient backboarded on a stretcher.
It also compresses my down bag more.
So what do you all do with your pads so you can protect the pad and sit up with the bivy?
Also, any tips from REI minimalist bivy users to keep the mesh off my face?
Thanks.

[l w]

Great article Ryan and great thread people.

I have a question to all the eVENT Unishelter owners out there. Now that ID makes the Crysallis in eVENT if you were buy a new ID eVENT bivy today would you choose it over the Unishelter. I am trying to choose between the 2 myself so any help would be nice.

The Crysallis is lighter, simpler to use(no poles/pegs), and has the ability to be unzipped half way (with bug netting protection too) for hot summer nights. The only downside that I can think of is a little less head room (which I think I’m ok with), maybe more condensation when in storm mode????

http://www.integraldesigns.com/product_detail.cfm?id=843&CFID=8653397&CFTOKEN=62601951&mainproducttypeid=1

[paul johnson]

DrJ,

I'll even go higher than the 40s with the Uni. I've used it even into the 60's. I'm quickly out from under my summer bag which usually is used semi-quilt under these conditions, or just layed on from the 'get go', and may even unzip, unbuckle, and pull up and down any clothing if i get warm, after leaving my head uncovered.

I might also, if weather is good and no bugs, unzip the Uni, thus making the aforementioned machinations (meant in the nicest of ways) with the sleep clothing unecessary in this case.

Worst case: hottest Summer nights can be around 87deg and 90+% RH. IME, no bivy performs well under these conditions, especially when one needs to be zipped up due to bugs. Tents aren't too great either, absolutely speaking.

BTW, y'all have it easy out West. My daughter, living in CA, tells me how much she loves camping and backpacking out there: no bugs, no humidity, no rain, and wide open spaces to make bivouac. 'Ok', so the PNW might be a bit diff. She's not that experienced, just places in CA and Yellowstone.

I totally agree with you on the simplicity and aesthtics of bivy use. It's really liberating.

One downside for some who are 'askeered' of critters, on RARE occasions one can more easily feel small critters, i.e. small nocturnal rodents, running over or even sitting on the bivy sack/shelter. At least the 'shelter' type :) of bivy keeps them off of my head. Usually this doesn't happen and when stealth camping, i usually have no 'Close Encounters of the Rodent Kind'. On the rare occasion that i've felt such, i've always hoped no owl was watching as those talons can accidentally make quick work of a WPB shell!!! Though i don't think that, in most cases, the owl would miss or perhaps even rake the bivy fabric when taking a small mouse. Could be wrong though as i've never, to my knowledge, had this type of owl encounter.

[paul johnson]

I don't have the ID eVENT Crysallis or any previous iteration of the Crysallis. However, i have some bivy sacks that are head opening like the Crysallis.

There are to be sure advantages to the Crysallis as you stated. However, i really don't like this type of b-sak as much as a Bugaboo/South Col (or similar) footend FACING opening bivy (bivy opens at headend, but the opening FACES the foot end, e.g. the Uni or Lightsabre, etc). Maybe it's just that i don't have any headend opener with a stiffened wire dome?

However, I find that when it does rain that i really have to close it up more than an opening facing the foot end. Sure, since it's not staked down, typically (though i may put one in the foot end to keep it from blowing away when i'm not in it when there's heavy winds and my UL gear inside can't weight it down enough to keep it from blowing away; nature call is one thing, running through nature at night chasing my bivy is another thing, however) i could sit up, get my arms outside and shift orientation, but…

Sometimes when it rains when using a footend FACING opeining b-sak, due to the overhang, i don't need to make any adjustments (unless it's unzipped down to my waist). Just continue to sleep away. In my case, counting on waking up due to some rain, even heavy, is 'iffy', at best. I sleep like a 'dead man'. In bear country (which i don't believe i ever really am in – even though 92 black bear sightings in the tiny State of CT in the Spring of '06), i'd probably wake up the next morning in the stomach of the bear!!! i sleep very soundly. I'd be soaked b/f i wake up. I've actually dreamed that i was taking a shower at home when i've been rained on in the past!!! Then it gets cold as i get wetter and waking from my dream, real life/reality becomes a nightmare!

I do have some OR clamshell/crocodile head end opening bivies. These work better, IMHO, than the one b-sak i have that, minus the wire stiffener, is cfg'd like the Crysallis. However, even these i don't like as much as a footend FACING opening b-sak/b-shelter. One advantage is that those whose opening face the footend often have an overhang so that i can still place the opening close to my mouth and exhale out of it even in the rain – this is when it is even more impt NOT to accumulate exhaled water vapor in the b-sak since given the outside RH being so high, it won't pass through the WPB shell as readily. The headend openers i have, when it's raining, require me to move closer to either side and turn my head to the side in order to attempt to exhale out of the b-sak as much as possible, which, in my case, OthersMMV, is NOT how i sleep (i sleep positioned like a dead person in a casket/coffin).

Lastly, ingress/egress in rain allows water entry. At least the Uni keeps most/all of the water out of the headend.

Some feel that a b-sak cfg like the Uni is the easiest to get in and out of (though shorter ones like the Lightsabre are supposedly more difficult for taller individuals; personally, i have no problem since i'm so short). Others like open a head end facing opener nearly all the way, sit down, pull their legs in, and lay back, while pulling the shell and/or netting over them as they do so. To each their own. I'm not sure that there is a best here.

I definitely prefer side zippered openers to mountaineering cross chest openers. All i need to do is throw my back out wriggling into one of those and i'll never get out in the morning – it would become my own personal little 'time capsule' of sorts.

I think that i may give the ID eVENT Crysallis a go and have already, some days ago when i read about it, 'Bookmarked' it for possible future purchase.

Considerations vs. the ID eVENT Uni:
Definite Pluses: no staking, so therefore simpler; way more bug netting – Hoo-yah!!
(tentative)Minuses: head end opening, less head room for reading, etc.

I'd really like to find someone to shorten and re-tape my ID eVENT Uni (or the ID eVENT Crysallis – IF i purchase one) since they are both EXP lengths, i could save some weight since i don't even need 5' 7" of 'fit', much less 6' 7". At 5' 7" to 5' 10" overall 'fit' length, i still have plenty of space at the ends for gear storage.

Don't know why ID doesn't make a shorter length. I've called twice over the last 2.5yrs or so, and asked them. Ans: No. They 'say', so to speak, on one of their webpages that they do custom orders, but they explained to me that is for Police/Military/SAR customers ordering in Qty, not single items.

Sorry, more than you bargained for, no doubt. Take what you need; leave the rest for eventual decomposition.

[paul johnson]

Nearly always INSIDE.

Outside a handful of times with some lighter weight bivies with LW fabric bottom, but ONLY when i've forgotten my GG Polycryo gndSht (or didn't think i would need it), or i couldn't find or prepare a good bivouac site.

For b-saks w/o a wire stiffener, i wear a ballcap to sleep in all but the hottest summer nights. the capbrim keeps any fabric or bug netting off of my face.

I've heard of some people placing relatively clean boots (like how often do UL hikers have 6"-8" high LW boots w/them?) in the headend to accomplish the same goal.

What i've done when i've needed to button up one of my OR clamshell/crocodile mouth headend facing opening b-saks is to place one (or sometimes both) trail runners on their heel or toe and sometimes use other gear to steady it in position. I don't move around much (or nearly at all), so i tend not to knock them over during the night. The same might be done in the case of your Minimalist bsak. However, in the case of the OR's it's more to keep the headend open a bit for ventilation than for holding the fabric off of my face since they have overhead delrin rods/poles for this purpose.

[David Olsen]

I would take issue with the durability ratings. Having
a floor made of the WP/B fabric may increase durability
as well as reduce condensation. The fabrics coated with
urethane will be similar in durability whether breathable
or not, and many of the PTFE laminates have proven to be
more durable over the long term than a simple coated nylon.
Just look at Rick Dreher's bivy. The urethane breaks
down faster than the teflon. This has been my experiance
in a goretex tent as well and on hundreds of gaiters I have
made for schools.

"Rick Dreher, Section Editor (Sacramento, CA)
Here’s a blast from the past. How about an Early Winters Sleep Inn Gore-Tex Bivy? Yep, that’s my bivy: it's fended off weather, condensation, bugs and ground moisture while extending my sleeping bag's temperature range and corralling my sleeping pad for three decades (give or take a year or two). While the generation one Gore-Tex still delivers waterproof protection, the floor's urethane coating is getting gooey. It's reasonably light (1 lb) and compact for what it does – more so than many featured bivy sacks in this review. Here’s the best part: I think the initial cost has amortized into an operating cost of something like three bucks a year."

"Durability of ultralight gear is a difficult category to assign ratings to. However, in a bivy sack, durability of the floor is a key component and predictor of its longevity. So, while bivy sacks with more durable uppers are rated higher in this category, it is the bivy sacks with the most durable floors that get the highest ratings. In addition, durability scores were lowered in bivy sacks where waterproof-breathable fabrics were used in the floor, because the waterproofness of those fabrics is particularly compromised when subjected to the abrasion and dirt that tends to plague bivy sack floors."

[Hideaki Terasawa]

Hello bivy campers!
Speaking from personal few experience..

I have a Crysallis(not eVent). I think Crysallis has drawback of design. The wire stiffener doesn't work well. It doesn't keep its shape.
http://pds.exblog.jp/pds/1/200607/24/55/e0024555_23332156.jpg
Bug net is inside of wire roof, so it veil your face. Crysallis has a air duct. But I couldn't feel helpfulness in the rain. I need to kiss to the duct when breathing.

I have a eVent Uni. I think eVent works well in the cold condition.
http://pds.exblog.jp/pds/1/200511/20/55/e0024555_17541415.jpg
But it has a structural defect. It has no rain flap over the zipper. Waterproof zipper isn't waterproof truly. YKK says so. You need a cup to scrape out water from pond inside of bivy in the strong rainy condition without tarp.
http://pds.exblog.jp/pds/1/200508/13/55/e0024555_1037477.jpg
I wonder what they wanted to save? A few pounds or me?
Uni type bivy needs stakes to keep head room.

I have a Biblar tripod. It need no stakes to keep shape of the head room. It has a rain flap. And it works well in the strong rain.
http://pds.exblog.jp/pds/1/200607/19/55/e0024555_0174886.jpg
I like it very much except its heavy weight :-(

I hope that Biblar make new tripod(or Lightsabre) using eVent.

[David Ure]

nm

[l w]

Wow…PJ Thanks for the taking the time to write that very informative reply. You have given me a lot to think about as did Hideaki Terasawa.

Also one thing I did notice was that on the OR preview on this site the eVENT Crysallis looks to have a waterproof zipper and on the ID site the picture show a traditional zipper and large flap. I wonder if they are getting feed back simular to HT’s. Perhaps soon the Unishelter will loose the waterproof zipper???

Anyways thanks again everyone for the info.

[Gary George]

I have a Crysallis in eVENT and think that it is the best all around bivy that I have ever used. I think that the wire stiffener works great. In heavy rain, I still take a small ID tarp. The way that this bivy opens, and with the rainflap over the zipper, I find this bivy the easiest to get your bag into and not worry about getting anything wet. Once in the bivy, the vent works great, but if I would like a little more air, I can unzip about a foot of the zipper on the side and prop it open. The rainflap over the zipper allowes this. Lots of options with this bivy! FWIW

[David Ure]

nm

[Denis Hazlewood]

pj,
Of course, it was right in front of my face the whole time. A friend of mine has the OR now. I'll pass your tip on to him.

Thanks,

Denis

[b d]

Thanks to the Gear Swap I just received my VAPR bivy. I can't wait to try it out.

My old OR was just too heavy to justify a lot of use, when my partner and I go together and a 2 person mesh walled stand alone would do or an HH/GG Squall Classic.

But, the State of the Market Report on bivy sacks pushed me to at least try it again and the comments by DrJ, pj, and others convinced me to go for it. Thus, I was ready and was able to get a VAPR bivy at the Gear Swap.

Thanks to all at BPL for the encouragement and information necessary to push forward and try, or retry, new ways and lighter pack weights.

[Eric S.]

http://www.ccoutdoorstore.com/outdoor-designs-ridge-raider-bivy.html
http://www.basegear.com/outdoordesigns-ridge-raider-event-bivi.html

It looks interesting, claims to be a 25.6 oz eVent hoop-style bivy, but I can't find any information (or even a picture, besides the cartoon drawing).

[Author]

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