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zpacks Pertex Quantum Bivy
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matt brisbin
(firestarter01) - F

Locale: Bay Area
zpacks Pertex Quantum Bivy on 12/05/2012 18:29:48 MST Print View

So I did some searching and didn't find anything on the new zpack bivy (says new as of 2012 on their site).

anyone have one? Thoughts? Likes/dislikes?


Stevie Patrick

Locale: Adirondacks
Pertex Quantum Bivy on 12/05/2012 21:44:05 MST Print View

I had the same problem. I had never tried a bivy and wanted to incorporate one into my winter setup. Saw it on the Zpacks page, and thought it was intriguing but couldn't find any info on it at all, even posted here with no responses. Regardless, I decided to pull the trigger on one, and actually used it for the first time this last weekend.

So I repeat, this is the first time I've used one. First, I'll go with the "likes." First off, it's super light, and packs down small. The bug net is optional, and just velcros off. I didn't use this option, since bugs aren't a problem right now. It definitely boosted the temperature in my duomid. I experience a little bit of condensation, but it didn't bother me at all. And now for the "dislikes." It's kind of a snug fit for me, I'm about 6'1" and 200 lbs, and sleep mostly on my side. It was tolerable, but I toss and turn a lot, and it was kind of tricky. Also, it's not fully enclosed without the net, which probably isn't a problem, but sort of lingered in the back of my mind.

Hope this helps/makes sense. I'm typing this on my phone. If you have any questions that I didn't cover, which I'm sure you do, feel free to ask and I'll do what I can to help.

matt brisbin
(firestarter01) - F

Locale: Bay Area
Thanks on 12/05/2012 21:50:57 MST Print View

Thanks for the quick reply, it does help.

I'll probably have an easier time with it in that case, 5'11 and about 145lbs. I'm mostly a side sleeper and was wondering about the head/shoulder room when the draw cord for the top is taunt? How much height (or air space above your head) would you say there is when the top is lifted up via the cord?

Also, in practice, how high would you say the cuben fiber walls are?

Stevie Patrick

Locale: Adirondacks
Re: Thanks on 12/05/2012 22:12:49 MST Print View

With the draw cord taunt, I'd say there's at least six inches of space between my head and the bivy, maybe more. And in use, the cuben walls actually extend quite a bit up the sides, once again, I'd say at least six inches. It actually helped cut down on wind quite a bit.

matt brisbin
(firestarter01) - F

Locale: Bay Area
Ordered on 12/06/2012 17:27:57 MST Print View

Well, I did it!

It's in the mail.

Nathan Lare
(cirque) - MLife
custom zpacks Pertex Quantum Bivy on 12/06/2012 21:22:41 MST Print View

I had the same questions about this bivy a few months back. I ended talking to Joe (via email) and I drew up some plans for a custom version of the bivy. It was slightly wider (74" girth - I'm 5' 11", 200 lbs. and a side sleeper) and the standard length. I modified the zipper placement to run across the chest and down the side about 20 inches. I had a full net hood and added a second hang loop in the zipper hem. The floor was made of 0.75 cuben. All summed up... it is a thing of beauty. It was built and shipped in about 3 days (even though I told Joe I wanted it for a date about 3 weeks out). Finished weight including bivy, stuff sack and bungie lines/cord locks for the screen was 5.0 ounces on the nose.

I have slept a couple nights in it. The first night was in the high 40s/ low 50s. I had the screen suspended from the loops and had no condensation at all. If I am remembering correctly I had a 40 degree quilt.

The second night was a few weeks later and it was closer to freezing ( a 22 degree quilt). This time I did not hang the screen. In the morning, I had frost on the outside of the bivy and condensation (beaded drops) between my quilt and the bivy. I pulled the bag out and wiped the drops off. I sunned if for about 30 minutes, but that was probably not necessary.

(Both nights I was under a DIY 2mil plastic tarp... the first night the foot was pitched higher and there was a slight breeze... the second night the foot was pitched closer to the ground and there was no breeze... I'm now tarp shopping for real :-) ).

Bottom line... beautiful product in appearance and function... AWESOME (bold, underline, exclamation) Service

Edited by cirque on 12/06/2012 21:23:51 MST.

matt brisbin
(firestarter01) - F

Locale: Bay Area
Review on 12/07/2012 13:00:05 MST Print View

Awesome. It just shipped so it looks like next weekend is backpacking for sure :-)

matt brisbin
(firestarter01) - F

Locale: Bay Area
Got it on 12/10/2012 22:19:01 MST Print View

That was fast, it's in my hands now and quite awesome. Although it doesn't look like I'll be getting out this weekend due to Holiday parties and such. I'll post once I've given it a good run...

matt brisbin
(firestarter01) - F

Locale: Bay Area
Trial Run on 01/01/2013 11:54:24 MST Print View

Figured I'd post since I actually got the bivy and poncho tarp (GoLite) out for some use. We headed out with the expectation of rain 10% the first night and 60% the following day.... well ... that didn't quite happen, instead, 4 inches of snow or so bombed us! Good times.

The bivy was perfect. No condensation, seemed to breath well, and I was quite comfortable which was slightly unexpected since I toss and turn a lot. Best of all it's extremely light. I've attached a pic of my setup and as you can see I have quite a long way to go in terms of knots. With the snow coming up pretty unexpectedly I didn't have it tensioned properly.... good thing there was no wind :-)

zpacks bivy trial run

I was using the "tauntline" adjustable self-binding knot at the stakes with rocks over the ridgeline ones. Now for some questions:

1. What adjustable knots do you prefer?
2. Are there any fancy knots that would allow me to adjust them while laying down inside the tarp, maybe via a tether. Yes, a lot to ask for!
3. The tauntline knot worked pretty well although I had to get up at one point to adjust the line and one knot came undone. Looking for any tips on making a better adjustable self-binding knot.

Mike Bozman
(myarmisonfire) - M

Locale: BC
Looks good on 01/01/2013 12:47:47 MST Print View

Matt, it seems as though you fared quite well with the unexpected snow!

Jeff J
(j.j.81) - F

Locale: Oregon
Taughtline on 01/01/2013 12:48:14 MST Print View

I have a similar setup for my truly UL setup, a GoLite PonchoTarp and a MYOG bivy. I use a taughtline hitch for all the guylines. It sounds like with that knot that came undone that you just need to practice more. Sitting and watching tv? Grab a shoelace and tie a hitch to the coffee table. Carry a bit of cord in your coat pocket and practice when standing in a line somewhere.

One tip is to have the fixed end at the stake and the hitch on the tarp, that way the knot is up out of the snow/grass/whatever and slightly more convenient to adjust. I don't usually do that but it's a possibility.

Also, don't forget to pack a line for the hood. I tie the hood off with the drawcord, but then I tension it out with a guyline to something. It improves the overall pitch and gives a touch more space under the tarp.

Lastly, while I use it probably the most in one form or another, I find an A-frame pitch with the GoLite PonchoTarp to not be very good. Serviceable, but the round hood breaks up an otherwise nice ridge. A half pyramid pitches tighter, at the cost of space and coverage. But that's why I usually use an A-frame despite the hood.

Hope any of this is helpful. Practice, practice, practice is all there is to it. I need more myself.