Nov 16, 2013 at 10:30 am #1309887
What is the best stand-alone bivy? That would be one that you could throw down with a protective ground sheet and pad and camp in any 3-season weather and stay dry and warm.Nov 16, 2013 at 12:01 pm #2045186
It seems a though a ul bivy paired with a cuben tarp or poncho tarp is a popular option around here.
Ex. We can get a 6oz bivy paired with a 4oz tarp.
The problem with waterproof bivys is condensation, even my m50 bivy I had to sell because of this in favor of a bug bivy.Nov 16, 2013 at 12:03 pm #2045188
@justin_bakerLocale: Santa Rosa, CA
I've heard good things about the MLD event bivy.Nov 16, 2013 at 12:33 pm #2045193
Mole JBPL Member
That would be one that you could throw down with a protective ground sheet and pad and camp in any 3-season weather and stay dry and warm.
Which to me means for use in heavy rain and wind?
Dry and warm once inside is easy enough. But useability trumps lightness in my book.
Effective WPB bivis are not really 'UL' kit IMO.
I've never used a groundsheet with a standalone bivi. What's the point of that? – the bivi is WP and won't blow away like a GS can. A GS also gathers rain into a pool under/around you! Have used a CCF mat outside the bag with smaller ones, but that is a pain too – IMO in wild weather, you want your mat inside the bivi if possible – dry and secure.
I have owned/used at least 8 different WPB bivis over the years (since mid 80's) – goretex, pertex shield, PU coated and eVent. (sold several on when deemed not suitable for my use – mostly not breathable or big enough)
My current bivis are British army goretex ( heavy but robust), an Alpkit Hunka XL (Lightish but more vulnerable) and a Rab Sierra (aka I.D. Bugaboo).
The thing they have in common is that all are roomy – enough to get full; size mats/sleeping bags inside, have wriggle room to change clothes, and room to store other gear. Need a effective way of avoiding rain ingress through the entry. The jury is out on the Rab Sierra as not had it in heavy rain yet (Waterproof zips with no flaps? mmmm….)
If expecting rain I use a MYOG microtarp with a bivi these daysNov 16, 2013 at 12:37 pm #2045194
I've been using the BD Twilight Bivy for about 3 years now.
I believe it weights about 10 or 11oz before seam sealing which you have to do.
The fabric is water proof. There is condensation, but not so bad in a dry climate if you breathe to the outside. It is what I would call a traditional climber bivy style: no zippers and a hood type entry. In order for the entry not to leak you would need to sleep propped up against something so that the water would roll off the hood onto the main body of the bivy. If you lie down the main body fabric would likely slope toward your neck and direct drainage that way.
Many bivys out there are NOT waterproof and/or leak at the entry. They are basically just sleeping bag covers. Zippers are always suspect. The traditional bivy is meant to be an emergency shelter sitting on a ledge… not a comfortable night and no fun. If I expect rain I either take a tent or bring a Cuben tarp for over the bivy. Still, I'm pretty confident this bivy would weather a significant rain if you spent the night with your upper body elevated.
Most of the other's I've seen are really just designed for light spray or tent condensation drip. They are really just sleeping bag covers, not really to be out in a real rain.
Bill D.Nov 16, 2013 at 12:44 pm #2045196
Kevin SchneringerBPL Member
@slammerLocale: Oklahoma Flat Lands
I have been researching the same issue for weeks.
It seems that there are some nice designs out there by Mainstream mfrs. but nothing that very light at all.
I already have a Borah Bivy w/ M50 and modified top. But I want a hooped Bivy so I am not trying to get the net up off my face just right.
It seems that there are no UL hooped Bivy option.
I just ordered some Cuben material .74 oz. for floor and sides. looking at doing netting over face and mid chest + and adding some WPB Cuben over foot box or maybe a piece of Pertex Quantum. not sure on the foot area yet.
I want a Bivy that I can just throw done on the ground and be done. and pair with my
Zpack 6 x9 tarp for rain protection.Nov 16, 2013 at 1:37 pm #2045215
Understood on the ground cloth issue. It seems that you would damage the bottom though.
Rain is the issue; otherwise, you could sleep under the stars— bugs aside.
Weight seems to go up in proportion to waterproofness. I wouldn't be adverse to a little more weight if traded for a simpler design.
Agreed on many UL bivies being sleeping bag covers to use with a small tarp to catch the spray and cut wind. I have looked at all the scenarios for using a tarp with a bivy and my Gatewood Cape trumps them all for weight and complexity, not to mention the fact that I already own one. I have a poncho shelter too, but that calls for as much complexity as a big tarp.
Hooped bivies approach UL solo tents in weight and cost. Bivies with pole designs are event more tent like. I tried a Black Diamond Lightsabre, which had all the drawbacks of a tent and a bivy— weight, complexity, no room, condensation, and cost.
I have an REI Minimalist bivy. They have approached the water into the face opening issue by putting a reversed storm flap across the chest to drain water off to the sides. The face opening is mostly exposed.
I wonder about using a waterproof/ breathable bivy with an umbrella to help at the head opening.Nov 16, 2013 at 1:50 pm #2045222
The REI Minimalist bivy is not even remotely water/weather proof as a stand alone bivy…. face is open, some zippers exposed. They are in the category of sleeping bag cover…
I groom the bivy location to prevent or minimize damage to the bottom fabric of my BD bivy… no hole after 3 years But I would avoid Cuben for the underside of a bivy as it is easily punctured and/or abraded. I would avoid using Cuben for anything that touches the ground.
I have looked around at the main stream Bivys and some of the cottage company offerings. I have yet to find anything that is waterproof and is not Cuben that matches the weight of the BD Twilight Bivy. If you find such an animal, please let me know….
Bill D.Nov 16, 2013 at 1:59 pm #2045227
However, if you are a big guy the BD Twilight Bivy might not be for you.
BNov 16, 2013 at 2:56 pm #2045255
Tony WongBPL Member
@valsharLocale: San Francisco Bay Area
MLD eVent Soul Side Zip in size large to allow room for you and your gear.
I am 5'6" and I put all of my gear above my head in the bivy and I put my Golite Jam 2 under my legs inside the bivy. Basically, everything inside the bivy with me.
I just keep my hydration bag outside and have the tube inside my bivy with a bite valve in the locked position by leaving a small hole open int he bug netting. (The MLD bivy I have from 2008 has two zippers for the bug netting.
That said, without a tarp, you are going to be very confined and miserable over a long period of time.
You would have to close us the bivy's head net to just a blow hole to keep the rain out.
Unless you can place the head portion of your bivy up against the base of a tree to give you some overhead protection from the falling rain.
TonyNov 16, 2013 at 3:01 pm #2045258
I have no experience with this product but I'm happy to see that they are now offering side zip and eVent bottom as options for their Snowyside eVent Bivy:Nov 16, 2013 at 4:29 pm #2045278
Using eVent for the top makes but I don't understand using it on the bottom. I'm assuming that body weight on a breathable fabric with any water under it would leak. Any thoughts?Nov 16, 2013 at 4:30 pm #2045279
That make 0 sense I don't care what reasoning.Nov 16, 2013 at 4:44 pm #2045280
@ejcfreeLocale: off grid
I used an OR Advanced Bivy for maybe 250 nights over 9 years. I found it totally weather proof even in extremely exposed inclement conditions. That's from the outside. Condensation could be very heavy at times. Everything, not that I had a lot, came inside and with some contortions dressing was ok. What I really loved was the feeling of being outside all the time and the small footprint. What I really came to dislike was the condensation and getting confined in there during long stretches of bad weather.Nov 16, 2013 at 4:54 pm #2045281
@justin_bakerLocale: Santa Rosa, CA
With a waterproof bivy, is the condensation enough to make you cold later in the night/early in the morning or does it take more than one night of use (without drying) to start getting cold?Nov 16, 2013 at 4:55 pm #2045283
The Ti Goat "Bug Bivy" is the only bivy that I own and plan to ever use. It will never suffer condensation. Your sleeping bag should provide your warmth, not your shelter.Nov 16, 2013 at 5:08 pm #2045288
I have the USGI bivy which is goretex. It's much more durable than silnyon and I haven't had problems with moisture coming through. I haven't owned an eVent bivy to know how it would hold up without a ground sheet.
Snark removed.Nov 16, 2013 at 5:09 pm #2045289
John,, with a full bug net top you'd be hurting in that Ti Goat Bug Bivy in a rain or snow storm. That's what the OP wanted info on… a bivy to stand alone in all season.
BNov 16, 2013 at 5:10 pm #2045290
@ejcfreeLocale: off grid
I experienced a huge range in the level of condensation in my GTX bivy. When the weather was right, mostly cool humid, it would require daily drying of the down bag and bivy interior. Many nights I had none but on the worst night, a thunderstorm transitioning into a snow storm, I got a puddle two feet around and an inch deep that totally soaked the lower half of my bag and forced the end of my trip and could have caused real trouble.Nov 16, 2013 at 5:13 pm #2045291
Fully aware of that… but my answer stands just the same.
Bottom line; for me bivies are too often used as a patch to cover a more structural problem with your gear selection. It's better to think through the needs of all your gear than to buy another piece of gear to fill in the holes. In the end, you'll save weight, money and have a better camp setup.Nov 16, 2013 at 5:23 pm #2045295
Removed.Nov 16, 2013 at 6:07 pm #2045304
"Sorry "That make 0 sense I don't care what reasoning." Better not buy one then. Problem solved. Hmm… better call Borah and tell them to remove it as an option since it doesn't meet your approval."
Ian, why reduce the thread to an unproductive middle school playground double dare attitutude? I too questioned the rational of using the fabric and you said you haven't used the product. If you can contribute something positive , please do, but I don't appreciate the negative sarcasm when we are all trying to exchange information and learn.
Can you please tell us the advantage of using a waterproof breathable fabric on the floor of a bivy?Nov 16, 2013 at 6:28 pm #2045310
Admittedly I overreacted to Michael and what I perceived as a snotty response. My experience with a full goretex bivy in a variety of harsh conditions is that it's durable to a point that I didn't have to use a ground sheet with it. It never had problems with ground water seeping in. Admittedly I often (certainly not always) would sleep with the bivy over a pad so that greatly extended my mileage but when I had to turn it back in after hundreds of nights of use, it was in awesome condition.
I've already disclosed that I haven't used eVent. I'm simply interested to know if it would have the same level of durability of goretex as this would be desirable in an alpine environment.
My apologies. I admit my response was crappy and I owe you a beverage.Nov 16, 2013 at 7:30 pm #2045323
Heat vapor etc rises to the top, an Event bottom I think is completley a waste. Where is it going to vent, the dirt?
Personally im against bivys, its an old school thing people used when the lightest tents they could find were 2-3 pounds.Nov 16, 2013 at 7:34 pm #2045324
You must be logged in to reply to this topic.