ZPacks Mini Tarp/ Rain Kilt $ XUL Shelter/ Sleep System

[Monte Masterson]

FKT or adventure race setup. This is a 52" square cuben fiber tarp with 8 tieouts. Weighs 2.2 oz. Under it is a WPB bivy (MB Dry-Tec LW 8.2 oz) which adds about 8 degrees of warmth to the sleep system. That means you can use a lighter sleeping bag/quilt. In warmer temps an S2S Reactor sleeping bag liner might be enough, or maybe just the bivy by itself. The main thing the tarp does is to protect the upper body and keeps the hiker/athlete from going crazy with rainfall hitting the head end of the bivy all night (lets you sleep). Total weight for bivy, tarp, stakes and lines is 12.7 oz. The most (breathable) protection and warmth per ounce you can get. Kilt mode. This is the tarp folded in half and secured with a ZPacks tape on tieout and spectra cord

[Ito Jakuchu]

Nice set up. Have you tested that MB bivy in rain? Have always been curious about if it holds up in heavy rain and if it is breathable enough. Would love to hear from someone that actually used it.

[Monte Masterson]

I find the Dry-Tec breathes quite well and it remains waterproof in light to medium rain showers. But with heavier sustained rainfall it will start to wet out a little. That can be remedied though. I made a duplicate of a lawn size garbage bag (40" X 30") out of light polycro and clear Scotch packaging tape. Weighs .9 oz. I can just slip that over the foot end when a heavy downpour appears imminent. It doesn't breathe, but that doesn't matter as much on the legs and feet. Also, I always carry a 40 inch long section of Ridgerest ccf cut into 10" wide sections and taped back together with clear Scotch packaging tape. Folds like a Z-Lite into a 10" X 19" rectangle. Then I use it as a frame for a frameless pack, a camp chair and a sit pad. More importantly, when it's time to bed down I place the ccf pad UNDER the bivy to help keep it off the ground, as well as to provide cushion to sleep on. Then only the biggest deluge can get the bivy soaked. sectionhiker.com also has a pretty lengthy review of the MB Breeze Dry-Tec.

[Ito Jakuchu]

Thanks. Just saw that at least in Japan they have GTX versions too, next to the Breeze DryTec ones. Will check them in the store next time I'm around. Again, cool set up.

[Dominic Camarda]

Hi Monte, I dig what you are doing, and even had the same idea at one time, but I think there may be more benefit to a heavier tarp and a lighter bivy rather than a mini tarp and a waterproof but heavier bivy…. unless there is something I am missing. For example, my Hexamid tarp weighs 7.2 oz (with stuff sack) and a Borah Cuben bivy weighs 4.2 oz.. so thats 11.4 total for a fully breathable bivy and full coverage (breathable/airy) tarp. Plus it only uses one pole/stick in case you didn't want to use hiking poles. More tarp coverage and more breathability for less weight… unless once again I am missing something like a cost factor or ???

[Dominic Camarda]

Sorry, not trying to derail your thread. Obviously I would lose the rain kilt with my setup. Like I said, I had once considered the WPB bivy with a small tarp for the torso/face at one time. But then realized a bigger tarp and lighter bivy seems to make more sense. Are there other benefits I'm missing to your setup? Thanks

[Monte Masterson]

You make some good points Dominic, but with the setup you're describing you don't get dual use of the tarp. You'd have to add a few more ounces to your overall weight for the rain kilt. You also don't get as much warmth from the Borahgear cuben bivy as the Dry-Tec, and hence you need a heavier bag. I had BG cuben bivy a couple of years ago and the Argon breathed great, however, the one thing I didn't like about it was the fact that the floor was so narrow and it allowed the Argon to touch the ground on the sides. But then again I had the large version, and with a 30 degree or warmer bag and a regular size bivy that might be negated. Yet I'd be afraid to go without a groundsheet (another 2 or 3 oz) with your setup, at least if I thought I might face heavy rains. I really do like the Hexamid/Cuben Bivy combo though. I also don't think you included stake weight in your 11.4 oz total. Another thing about the mini tarp is that it's more versatile. If you need to stop for a food break in the rain, it can easily be set up to provide cover. I own a Hexamid tent and I must say that any way you surround your wagons, it provides the most protection per weight than any other tent on the market. Love those ZPacks shelters.

[Mike M]

me likes :) I used a similar setup on the Bob Marshall Open last year, albeit heavier- MLD eVENT bivy (large 13.7 oz) and a MLD "dog" sil tarp 5×5' 7.2 oz w/ guys/stakes (4) it worked really well, the small tarp took just a minute or so to setup, roll the bivy out- done; like you said having a small rain free zone for sleeping and eating is nice I took a pair of sil chaps, but you got me thinking I might be able to fashion a kilt out of the small tarp

[Dominic Camarda]

Didn't realize you included the stake weight. Pretty cool. I wasn't familiar with that bivy either. Need to look into it more! Thanks for sharing this set up!

[Monte Masterson]

Another good thing about the 52" square Zpacks tarp is cost. Since it doesn't have a seam (cuben comes in 54" wide rolls) Joe is able to give a much better price. I paid $75 2 years ago and I don't think he's gone up any.

[Adam Kilpatrick]

This is a great thread Monte I like the idea of a mini tarp with WPB a lot. There are large potential time savings to be had vs futzing around with a larger tarp all the time…say you find some marginal shelter (eg base of good large tree), you have the easy option of just deploying the bivy, even with heavy rain. You never have that option with a large tarp/DWR bivy scenario. On an FKT remember, you aren't always setting up for a long time-could just be a short sleep. Usually if you are pushing hard enough, your faculties won't be working that great, it could be pitch black, in a rainstorm…not great conditions to have to set up a full tarp-time blowouts. Make a small mistake in tarp pitch and fall hard asleep…waking up in a pool of water is better in a WPB bivy than in a DWR one. I've had some ideas along this line myself lately…I want to do a bunch of MYOG and tests, I'll report back in a couple of months time…

[John S.]

Getting in a bivy (and confined to) in the rain won't be much fun either.

[Monte Masterson]

It's no secret that a bivy isn't quite as comfortable as a tent, but this is FKT and Adventure Racing we're talking about. The mini tarp somewhat alleviates the constricting nature of a bivy by allowing the hiker/athlete to pull it down to the chest, at least if sideways blowing rains aren't present. Don't forget how important weight is for these people. When running 40 miles plus a day, the effects of every gram get amplified. Sacrificing a little comfort to get uberlight is something adventure racers are willing to accept.

[Ian]

Good stuff Monte. I've recently acquired a blizzard bag that I still need to put through its paces but do know that it's waterproof. This would be a good solution for me when I decide to pack a hard shell instead of a poncho. Something for me to ponder.

[Ralph Burgess]

Some nice ideas Monte et al, I missed this thread when you first posted. As an alternative to the cuben mini-tarp/kilt concept, I took a SOL emergency blanket on my JMT attempt. The anticipated use was slightly different. I was not expecting to pitch it as a tarp as a routine matter — I planned on a low probability of rain for my setup to be adequate. However, I did reinforce tie-out points with tape, and took enough Dyneema cord that it could have been pitched in emergency. I think it's not strong enough to consider pitching it as a routine matter, Cuben is undoubtedly better in that role. It's a similar weight to the light Cuben that you're using here (a fraction lighter, 56" x 84" = 2.9oz). The primary advantage for me was that it's much warmer then Cuben as emergency insulation (and much warmer and stronger than regular Mylar emergency blankets). It's far more easily damaged by (say) sharp rocks than Cuben. Only $5 so you can take a new one on every trip where it's a critical element in your setup. If undamaged it's waterproof and non-breathable. For me, it served routinely as a groundsheet. The one I took was a full-body blanket size (2.9oz), larger than your tarp, so the possible configurations in various gradations of non-routine weather or injury were – – unexpected light rain or chill while sleeping, roll myself up in the groundsheet as a temporary cover (noting that its totally non-breathable) – rain kilt – pitched as tarp – if injured or hypothermic, wrapped around me while sitting or hunkered down (warm and rainproof)

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