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

[Hideaki Terasawa]

Hi Eric,

Maybe it is OEM of "RAB Ridge Raider"
http://www.rab.uk.com/products_shelter_ridgera.html

[l w]

Hideaki Terasawa is right, it is a Rab product. From what I understand Rab acquired OD and moved the entire OD shelter line over to the Rab brand. This bivy looks like the only real competitor the ID eVENT Unishelter. This product is most likely not to be found in North America and if you ordered from a UK dealer the price and duties could really add up.

I think for myself I am going to take the plunge on the eVENT Crysallis.

[paul johnson]

Some time ago, i spoke with both a UK dealer (telcon) and BaseGear (email) about this bivy.

Seems very nice.

Main downside i see is the peak height (~25", IIRC) and the contortions one must go through in order to enter the bivy (enter backwards on all fours) and exit the bivy (perhaps a bit easier exiting forward vs. entering backward). This is the main reason why many prefer the footend facing opening found in the Uni's and Bibler/BD bivies, or the OR style clamshell/crocodile-mouth opening bivies.

The headend facing opening configuration has some pluses relative to rain entry wetting one's bag, as well as ease of reaching out to cook or melt snow while still remaining somewhat inside one's bivy.

These comments are largely intuitive in nature and extrapolated from my single use of a Eureka Solitaire which is similar in headend facing opening design (though my Solitaire,which is the latest iteration of the design, also has a zippered opening in the main bug canopy).

[paul johnson]

Ques: Have i ever gotten wet/damp in the ID eVENT Uni?
Short Ans: Yes.
Long Ans: Yes, damp from internal condensation.

The rainflap/overhang at the head end allows venting when it's raining, this coupled with the tunnel vent works fairly well IF there is a breeze. Doesn't work if there is no breeze.

The ID eVENT Uni is mainly designed for the type of weather they get in the Canadian Rockies is what the designer of the Uni told me in a telcon (relatively dry and windy was how it was described, though i was told that there was no reason why i couldn't use the eVENT Uni in humid, rainy New England. I'm using mine in an unintended climate situation.

I've never had a pond forming inside.

Here's my take (i.e. guess) on Terasawa-san's leakage issue.

Normally, i'd say that one is confusing condensation under humid, no breeze conditions, particularly when it's difficult to exhale one's breath outside of the Uni (due to the 25" peak height in contrast to the typically much lower wire stiffened peak's of many bivy shelters which make it easier to do this).

However, a "pond" is too much moisture, IMHO, to be attributed to condensation.

My guess is a defective zipper, or possibly the zipper somehow was oriented skyward and water pooled on the zipper.

ID uses, on their eVENT bivies, a self-sealing zipper similar to the one used on their rain jackets. I'm guessing that perhaps(???) the zipper was paritally damaged in one location during normal use. NOTE that this self-sealing zipper is used on ID's eVENT Uni, Bugaboo, and their new Crysallis. The ID website photo of the Crysallis [click 'me', i'm a hyperlink] showing the rain flap over the zipper is, IIRC, an OLD photo of their pre-eVENT version made from TegralTex (this photo was in use for a few years BEFORE ID even introduced the eVENT version of the Crysallis). Compare that photo with the photo of the eVENT Crysallis found HERE – particularly see the second pic which more clearly shows what, IMHO, is identical to the self-sealing zipper on my eVENT Uni and that there is no rain flap over the zipper.

ID states that there is NO skyward facing zipper. The zipper in the eVENT Crysallis and eVENT Uni is sideward facing. This is supposed to prevent water pooling on top of the zipper.

After reading Terasawa-san's post, i decided to recheck my eVENT Uni for water leakage.

First off, a couple of years ago or so, before ever using my eVENT Uni, i gave it a 20min shower in my shower with me inside. Zero water penetration over that 20min period. Shower was perhaps equivalent to a moderate to heavy rain out in the open with no tarp or tree cover to hamper the "rainfall".

So, now after reading Terasawa-san's post, i did four tests of my somewhat used eVENT Uni (over two dozen nights of use – normally if i'm expecting heavy rain, or it is raining heavily, i use a PT in a lean-to pitch over the bivy – not always, but often, and/or pitch the bivy under tree cover – which is far more frequent).

Test #1: Ran water from the kitchen sink faucet over the bivy zipper. Faucet was on full-blast and zipper was 2" from faucet. Within two seconds, STANDING WATER ON THE ZIPPER penetrated to the inside. Easily enough penetrated to create a pond during the course of a night's use.

Test #2: From a distance of 12"-18" from the zippered self-sealing zipper which was unnaturally vertically oriented instead of horizontally oriented as it would be in actual use, blasted the zipper from the kitchen's sink's spray nozzle with the water on full-blast. Much better, i literally found just two drops of water after 60seconds of spraying. The spray was quite forceful and water pressure was perhaps similar to or greater than a torrential downpour (much more than the equivalent 4" of rainfall per hour). I repeated this test on a dry area of the zipper using just a light to moderate sprinkle which was not very forceful. ZERO water penetration in a sixty second test.

Test #3: Oriented zipper horizontally as it would be in actual use and sprayed for sixty seconds just as in step #2 (12"-18" away, so a forceful full-blast spray) fabric just above zipper and water ran down side of bivy fabric over zipper and continued down. ZERO water penetration afer sixty seconds of high velocity spray NOT directly on the zipper (other than perhaps some incidental forceful spray).

Test #4: 20minute shower test as performed before first use of the bivy. Zipper once again NOT directly being "rained" upon. ZERO water penetration through the zipper.

I would agree with Terasawa-san that a rain flap is superior to a self-sealing zipper.

The key to use of the self-sealing zipper seems to be to not orient the zipper so that water can pool on it. My simple testing shows that it is possible for pooling water to enter through the zipper (of course, in my simple test it might have also been the pressure of the water flow from the faucet which was only 2" away which forced the pooled water through the zipper – we really need better testing than i did to be sure).

Regarding a comparison of the Uni with the Bibler Tripod bivy, which i intend to purchase one day if i'm going to be winter camping when snowfall is expected. Of course, having only one head end pole to wrestle with instead of two poles (like in the Bibler Tripod), the head end must be staked out to give it some shape (which is a bit loose and not completely taut). Of course, the Tripod is staked at the footend since it uses only one pole there. I would imagine that the Tripod is better at handling snow loading and in particular compression of one's sleeping bag due to that snow loading, if it is tightly pitched since it has both head and foot end poles. Any bivy should be staked down to prevent strong winds from blowing it away when a person might be out of it (e.g. nighttime nature call).

I also repeated the faucet and spray nozzle tests (not the shower test) with my ID eVENT rain jacket. Essentially, similar results were acheived. Test #1 – water readily penetrated through the zipper after a couple of seconds. Test #2: did the vertical direct spray test twice as the first 60second test, no water penetrated the rain jacket. Repeated Test #2 and the second time had four drops that i could find. No water penetrated when Test #3 was performed.

[l w]

Thanks for posting your test results on the ID waterproof zippers PJ. This info is very valuable to the BPL community.

In regards to the eVENT Crysallis bivy, are you sure it has a wp zipper as opposed to flap? The post above by Gary George states otherwise. Also on the ID website, the info provided for the eVENT Crysallis does not say it uses a wp zipper but if you look at the other ID eVENT bivies that have zippers the info clearly states the use of wp zippers. Hmm I guess I will have to e-mail ID to find out for sure.

[Ryan Jordan]

I've had it in heavy rains and never had water entry into the bivy sack. But, I do think that as the zipper wears out (after all it is a PU coating subject to UV degradation and physical wear) that this will be the likely point of failure, at which time it might be worth sewing a silnylon flap over the zipper.

[paul johnson]

LW,

No. I'm NOT sure (never having seen one except in pics on BPL.com). I think that Gary George might(???) be thinking of the TegralTex version of the bivy which also seems like a very nice design – even better due to the rain flap, but the fabric is supposedly not as breathable as eVENT.

However, i can tell you that the pic on the ID website has been there for 2+ years, over which time it was the pic of the TegralTex version of the Crysallis.

Clearly, (or not so clearly is perhaps closer to the truth), the second pic on the BPL.com article that i linked to in my prev. post shows just a WP zip and no rain flap.

I'm sure Mike Martin (who wrote the article for BPL.com) could weigh in here and tell us. Well, Michael, does it, doesn't it, and was the pic just a prototype and if so, will the mass produced one have a rain flap or just a WP zip? We're all ears.

---

In the eVENT of a leaking zipper, dry the area on the inside and perform a simple repair using duct tape that should last through the night. Of course, you might need enough duct tape to go the length of the zip – at least from the defective/leaking portion on down to the end. Otherwise, the gravity might pull the penetrated rain down to a lower point, or the lowest point, and then it would leak through. I once used duct tape to temporarily fix a leaking bathroom sink drain standpipe (old house; old plumbing, corroded through). Just to see how long it would hold (Nashua 357 tape = duct tape on steroids), i left it in place even after i rounded up the new parts. IIRC, two weeks, before the hot/warm water (probably???) softened the adhesive enough and started to drip through. So, i think that it would work for a night, or two, or three. Anyone see any problems with using duct tape for this purpose?

[David Ure]

nm

[Gary George]

I happen to be looking at MY crysallis bivy in eVENT, and it has the rainflap that covers the zipper. I own the crysallis in both materials.

[paul johnson]

Sounds like Maaax must have purchased his before the design was finalized or changed. Looks like Maaax got the best of both worlds – eVENT+rainFlap. Way to go Maaax!

---

David, did the note from ID specifically state that the eVENT Crysallis did NOT have a rain flap, or did it only mention that it had a WP zipper?

[Roger B]

I own a Ridge Raider and used it in Norway in Summer. PJ is correct, it is like getting into a sleeping bag that does not have a zip. However, waking up in the morning with the sight of the mountains in the foreground is an experience that I will never forget. I intend to use it in the coming months on the AT, it is not ultralight but I know I can rely on it.
There is no waterproof zip but it does have a flap.

The weight without stakes is about 25 oz or 730 gms, the Rab website now suggests that the weight is 33 oz, so their design may have changed (or the stakes have got heavier). It is smaller than the ID Unishelter but for me it worked and I will continue to use it in conjunction with (if necessary) a small tarp.

I purchased mine from a company in the UK. PM me if you want the details

[David Ure]

nm

[Hideaki Terasawa]

Thank you pj.
I was impressed by experimental verification you did.
Great!

I must learn designer's intention before I use it.

[paul johnson]

Too bad. I was hoping for the eVENT + rain flap in the final design. Now, if only someone had a Crysallis bivy with both features (i.e. eVENT+rainFlap) that they would be willing to sell? I'd make a handsome offer.

[Roger B]

Gary

I am interested in in the no-see-um netting backing on the ID Crysallis what is the length of the netting? From the BPL review it appears to be about 30 inches. And does the wire stiffened dome keep the netting off the face as well, or is it only the eVent outer?

Thanks

[Gary George]

Netting is a good 36" long and there is not a wire in the face netting. This would be an easy fix, and I am planning to make it.

[Thomas Knighton]

Does anyone know how the equinox bivy was able to be rated a 3.0 for insect comfort? I can't find any pics that seem to show any no-see-um netting or anything. Am I just missing it?

Tom

[Richard Scruggs]

Great Survey of the state of the bivy market, but couldn't figure out how to educate myself further by reading the article staying dry in a bivy by Mike Martin that the survey first cross-references about a third of the way through the Survey (at the very end of the section on Fabrics) as follows:

"For a more thorough treatment of moisture management in bivy sacks, the reader is referred elsewhere (See “Staying dry in a bivy sack: techniques for managing the moisture balance between external precipitation and internal condensation,” by Mike Martin, Backpacking Light Magazine, Issue No. 7).

I immediately rummaged around for my copy of Issue No. 7, but it appears that the most recent issue I've received (and not too long ago either, if I recall correctly) is Issue No. 6. I figured Issue No. 7 must be coming along pretty quick, and I had just not received it yet.

But then, at the end of the Survey, there's another cite to Mike's article – this time referring to Issue No. 6 of BPL Magazine (rather than Issue No. 7). Didn't recall seeing such an article in my Issue No. 6, the issue which as indicated above had most recently reached my mail box. But, nevertheless, I searched through Issue 6 just to be sure, and I still don't find Mike's article anywhere there.

Please let me know where/when to look for Mike's article, or just let me know if I'm hallucinating about it.

This is urgent because I'm thinking about taking advantage of our temps below 20 degrees this week to try out my Arc Alpinist with my Bibler Winter Bivy (pre-Black Diamond version) & a very early version of BPL's current "vapor" bivy (a Bozeman Mountain Works Quantum X that I purchased from BPL in October 2003).

PS — I like to read the book before seeing the movie, too.

Thanks,

JRS

[Brian James]

I was re-reading this for about the fifth time when it suddenly came to me: when calculating the weight of a bivy-based or bivy-only shelter system, you have to take into account the boost in temperature rating that the bivy gives your sleeping bag or quilt.

That is:

a) 1lb bag + 2lb tent = 3lb, 32F sleep system
b) 1lb bag + 2lb bivy = 3lb, 25F sleep system

To properly compare, you must make the sleep systems equally warm. i.e.:

a) 1lb bag + 2lb tent + 8 oz cocoon pullover = 25F sleep system
b) 1lb bag + 2lb bivy = 25F sleep system

So even if your bivy is heavier than your tarptent or tent, remember that there's an inherent weight savings in the temperature advantage of a bivy shelter.

[Randy K]

It looks like Black Diamond decided to address, at least to a certain extent, the condensation problems with the LS by adding a foot vent and pole. Unfortunately, the mods come at a price, .2 pound, according to this web site.

http://www.moontrail.com/blackdiamond-lightsabre.php

Scroll down, this site has the best pics around.

Interesting!
roosterk

[John Carter]

I've been giving some thought to the Nemo GoGo bivy, and I'm wondering why it is not a superior bivy to the Unishelter. The original hesitation was a PU coated membrane, but now they have a fabric comparable to eVENT (still needs to be independently verified). The other main concern has been condensation. But the review that I found which complained of condensation mentioned it was only when he had the shelter completely closed. But anyone who's used a tarpent knows not to close the entire awning! I wonder if pulling the mesh inner out of the way and partially unzipping one side of the awning would alleviate much of the condensation problem. It would certainly provide a larger opening than the Unishelter in bad weather.

In addition to this, I sent an email to the company asking some questions, and learned that they will have an updated GoGo in May. It will include a swallowtail modification at the footbox to lift the fabric off the feet. Thus, even if the GoGo is more prone to condensation, that condensation will be off the bag and ready to be wiped off. In the Unishelter, a sleeping bag is touching the walls, soaking up all the condensation on the walls. I could be wrong about this as I have not actually gotten into one.

So these potentially solve the big issues. But there are other advantages I see as well:

1) Ryan Jordan says he likes the GoGo except for the wiggle factor of entry and exit. But if you look at the instruction manual on their website (http://www.nemoequipment.com/pdfs/GOGO%20Product%20Manual.pdf), it shows that if you unhook the vestibule and unzip the mesh, you can push the hoop forward and crawl in from above. Reversing this process would allow you to sit upright to enjoy the sunrise, or even to gaze at the stars while lying down. How different is this entry method from any of the bivys sold on this website without side zippers?

2) Just how does one get into and out of a Unishelter during a heavy rain? You still need to bring a small tarp, increasing complexity. With the GoGo, you can kneel down in the 27" high awning (with one flap open and the other tied down), take off your pants, slide in halfway, remove your jacket, and slip inside. Yes, there will be wiggling, but would you rather set up a tarp in high winds on a ridge instead? The GoGo is more spacious, with an inside height of 27 in and inner width of 37 in, plus the awning for cooking and storing gear.

I've been testing an ID Crysallis, and, while a nice bivy, still requires a small tarp, and you must stake out or tie off the mesh netting. The Crysallis plus my 4.6 oz tarp & cords weigh the same as the GoGo, but the GoGo keeps the mesh off your face, and I am dissapointed with the wire mechanism on the Crysallis.

3) The instructions also point out that if you are camping on rock or hard ground, you can push your gear into the back of the vestibule area, and that gear plus your body weight in the main bivy will keep the hoop upright. This is also great if you are beating a storm and don't have time to stake it out. Yes, you can probably also do this with the Unishelter, but the GoGo has the advantage of being able to inflate from the inside. The tube stays in place when you pack it. Therefore you literally could crawl into the bivy during a storm, inflate the tube (the company emailed me that it takes 15 seconds to inflate), push your gear into the vestibule, and have a functioning bivy in a storm. Plus, you don't need to carry poles in your backpack.

4) The GoGo has stake out points near your knees as well as at the foot. Staking at the knees will keep the hoop fully upright and taught, so the footbox need not be staked down even in stormy weather. This will allow you to curl up your legs and otherwise have a freedom of movement on your lower body. My understanding is that the Unishelter can only be staked at the footbox, thus limiting mobility when staked down, the way a full lenghth sleeping pad tied to a sleeping bag ties you down.

5) The other product improvement for the May upgrade is that they are designing a new tube that will be a few ounces lighter. If this is the case, the GoGo will be lighter than the Unishelter (and lighter than my Crysallis/tarp combo), will be more roomy, you can leave the tarp at home, and is easier to set up. Am I missing something here? I'm thinking of returning the Crysallis for the GoGo.

[Sam Haraldson]

We have a 2006 Nemo GoGo at the gear shop I work at part time and I set it up for the first time last week to give it a feel.

Inflating the tube takes more like five seconds than fifteen so that time is nearly negligible and as you mentioned, can be done from inside making this an excellent rain shelter. You can literally roll this out and climb in, inflate the tube, sit up and reach out to do the stakes located at the knees (only available on the 2007 models) and then flip onto your stomach and stretch out the front end and stake the vestibule area. This will be enough to hold up the airbeam and leaves the foot area loose to move around.

I set this up inside the store so I can't comment on condensation and waterproof issues of the fabric although I have looked at the companies testing statistics and the fabric rates well.

[Scott Lloyd]

Sam,
Could you provide us with a few details regarding the breathability of the Nemo GoGo?

[John Carter]

Thank you Sam for giving it a try. It's nice to hear that you can do all the required staking from within the bivy as I had hoped. I too am interested in breathability specs.

[Sam Haraldson]

Below is the verbatim information from the 2006 Nemo Fabric Specs binder provided to us when they shipped us our GoGo and Hypno EX tents.

NEMO Osmo™
Color: Birch leaf Green
Classification: PU Laminated Ripstop Nylon

Specs:
Coating: n/a
Lamination: Polyurethane (wp/b)
Thread Count: n/a
Denier: 30
Treatments: DWR
Weight: 2.14 oz./sq. yd.

Test Performed:
Water Vapor Transmission ASTM E96 Method BW: WVT grams/24hr meter-squared: 5120
Water Proofness ASTM 3393: Specimens tested 10 with 0 specimens penetrated
Water Repellency AATCC22 (spray test): Specimen #1 100, #2 100, #3 100 (a rating of 100 is equal to No sticking or wetting of the specimen face.

There is also fabric information in regards to the GoGo's stuff sack and airbeam material but they have little bearing on the conversation at hand.

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