Mountain Hardwear Conduit SL Bivy - 2007 BCS

I used this for a night in a snow cave in the WA Cascades. In the morning it was snowing and I had slid slightly out of the cave so my feet were getting snowed on. No problems with wetness or anything. No moisture buildup and my bag etc were warm and dry all night. Just make sure you get one with the zipper on the same side as your sleeping bag. It can work with the zippers on opposing sides but would be nicer if they were on the same side.

Spent a night in the WA Cascades with this product in a snow cave. In the morning there was a dusting of snow on my feet but I was dry and warm. No moisture build up on the inside. This will be part of my standard pack from now on.

I've use this bivy for a couple of nights now winter camping in somewhat spring-like conditions. I chose it because it is the closest thing to an OR bivy I had that would be ~20 years old now. Simple, no net or tent-like thing. The one new feature, that it zips into my sleeping bag, is awesome, bivy and bag travel as one unit now. I haven't taken it out in any rainy conditions, but it has kept my bag dry in snow caves and trenches. Some condensation, but not nearly as much as I got with my old bivy.

I picked up this bivy a couple of months ago and have been very pleased with it ever since! Pros: It doesn't add much weight. It slides over my Big Agnes extra long bag very easily. It also zipped onto my BA bag nicely which I was a little surprised about. It definitely keeps the undesireables out or off of your bag. It did add a little bit of warmth which was nice up in the sinks at -30ºf. Cons: The only thing I could think of was that if you sleep with the bivy above your face you can get a little condensation inside. It did dry very quickly though so it wasn't a big deal. We'll see how it does on the dirt this summer but I expect it will be great!

I've owned this product for over year and still can't make up my mind if it was a good purchase.

I got it to use as an extra layer of protection from light snow and condensation during winter camping in tents and shelters. On several occasions in the Adirondacks on 15-20 degree nights have found it to actually cause my sleeping bag to get damper on the outer surfaces than when I used nothing.

Recently I've used it to sleep out sans tent in 30 degree nights through light rain/snow and it performed well. My sleeping bag and I remained dry.

My theory is that in a confined space such as a tent or shelter (in this case a 3 walled AT stye shelter with a tarp across the front to block wind) the air itself becomes moist from the people inhabiting that space. This prevents efficient moisture transfer through the Conduit SL material. However, when used outside in open air the Conduit SL material does not appear to have this issue.

I haven't used it in warmer temperatures or in a true wet/rainy situation so I can't comment on that.

I'd recommend it for tarp or open air campers only.

I'm a huge fan of mountain hardwear, but i think they really dropped the ball on this one. I've used my bivy several times for winter camping, with temps between -10 and 15. every morning, i wake up with a layer of ice between the bivy and my bag from condensation freezing. the conduit top works great, but the bath-tub style bottom locks in the moisture. in addition to getting a soggy, icy bag, the zipper doesn't match. the tabs are both on the same side. pros: it's lightweight, packs small and not too expensive.

The bivy is great. I'm 6'3" and 265lbs - I need a little more room to turn sideways in the shoulder area. Other than that - I highly recommend this bivy!

On if you like bivies or not. If you're a bivy enthusiast, the SL is one of the best on the market (hands down). On a recent trip in the Sawtooths, the bivy performed very well in rain and breathed excellently. I wouldn't recommend using it without any kind of backup tarp - it won't remain waterproof in heavy, sustained rain. Also, I was eaten alive by mosquitos (there's absolutely NO mesh netting).

After pretty extensive experience in the backcountry and camping otherwise, I've learned that carrying a few extra ounces (or even up to a pound) for a high quality solo ultralight tent is far preferable. It allows you a sheltered place to relax during the day (or a long storm - not to mention a vestibule), and the mesh alone is worth admission, especially in bug-heavy locales. By the time you add up the weight of a bivy, a light tarp, and a few stakes, there's only ounces difference between the best ultralights on the market (MSR Hubba, Marmot EOS 1P, etc.).

Having that said, let me reiterate: this is far and away the best bivy I've ever used. Mountain Hardwear makes diesel gear, and if you're looking for a bivy that breathes well and has pretty good weatherproof chops - this is your bivy. I especially like it as an overlayer on a down bag for snow cave/winter camping. As for other reviewer's comments on getting wet in the head/shoulder region: that's just the nature of the beast with bivies, even more elevated ones (like Black Diamond's tripod bivy).

I had a Feathered Friends sleeping bag made with a zipper to fit this bivy and have enjoyed using it. The bivy has two sets of zippers. Your sleeping bag zips into the inner zipper of the bivy and the outer bivy zipper closes the both as a whole. I really like this set-up. It makes your bivy and bag into one unit. The bivy bottom is utterly water-proof. It is made from a tent bottom like material. The bivy upper is Mountain Hardwear's Coduit SL material. It is VERY breathable. It will withstand some amount of water, but a good dousing will soak it through. Overall, I recommend the bivy. I think it makes excellent protection your sleeping bag when you may only have partial protection from the elements. I have used it for tarp camping with much success.

I'd read that adding a bivy sack to one's sleeping plan could add a few degrees. I've slept in my 20 degree North Face Cat's Meow sleeping back in a two man tent with a fellow camper in 14F before and was a bit cold. I added a home-made fleece liner and this bivy and was toasty warm (no, really, toasty warm!) at -5F in a similar tent with a similar (heh) fellow camper. So, this bivy performed just as I hoped. I've also slept out in sub-freezing temperatures with no tent and did not find myself too damp from condensation --a very slight amount more than when just sleeping in my bag, but nothing to worry about (definitely not wet enough to be a danger).
I would recommend this product to friends and family.

Good bivy, especially if you have a Mountain Hardwear sleeping bag that zips to it. A little heavy if you want the minimum. I'm 6', and it was too short. Also, when I put it over my old Marmot Snow Goose Sleeping Bag, it got way too compressed. I sent it back.

I used this bivy on a 6 day hike over New Year break in the Smoky Mtn Natl Park. I stayed in shelters (required), but wanted protection from weather if I got stuck out on the AT. Two nights it was bitter cold (0 degrees) and the condensation from my breath caused my neck and head to become very wet. I contacted the Conduit company to see if I did anything incorrectly in using their product - no response. The Backcountry chat expert said this is a typical problem with bivies and the only solution is to keep your head outside the bivy. My soulution was to take the bivy off my bag and not use it when I had to cover my head due to the cold. It seems to me if you have to stick your head out of the bivy in the rain it would allow water to enter unless you put a small tarp over your head. I'm debating on returning it.

Mountain Hardware came through on this bivy design. The combo of my North Face Momentum 900 sleeping bag and the MH Bivy made a warmth combination hard to beat. - it may have been -1F outside - not including wind chill - but the warmth of this combo made it difficult to get out of the tent in the AM.

I've been looking at bivys for a bit. I just wanted a simple, small, and inexpensive one. This one is perfect. I've only used it three times but I can already tell it's going to be nice. Once in light rain (it really is waterproof) and two other times in about 30 degree weather. Some things I really like: side zipper for easy access, when I'm not worried about tight packing I can store and transport with the pad and sleeping bag inside then it's ready to go - easy setup.

Just what's needed for my down bag. Perfectly waterproof and breathable. Who needs a tent with a good back attached to a bivy? The fun of backpacking for me is traveling, not carrying a bunch of sh...stuff. Plus, get a little closer to nature, sleeping more or less totally outdoors with a bivy, instead shutting yourself in a tent, a portable house. With my 0 degree down Marmot bag, winter camping is comfortable and warm, and easy! Finally, easy winter sleeping! I tested this combo in my backyard in a snowcave I made, and was toasty warm immediately, not having to warm it with my body temp. When my cave collapsed(!) and I went inside I was colder in my bed! The only downside for me is the fit between bag and bivy zippers. Namely, they didn't, but with a little jimmy-rigging with a file, I got it to work. I'm a little worried about separating them and reuniting them again, but I don't need to! Why would I want to separate my warmth from water-proofing? Recommended, nonetheless.

This bivi bag has been used on a scottish walking trip where an overnight bivi was required, as you would expect it rained heavily but the bivi bag kept me very dry with very very little condensation on the inside so the breathable conduit sl fabric performed excellently. The rain just runs off it with not a drop getting through. If you want a very light very waterproof bivi then this is for you.

After purchasing the Black Diamond Winter bivy that uses Nextec's Epic fabric, I decided to compare it to the Mountain Hardware bivy that uses the Conduit SL fabric because of the condensation that I experienced inside. They both seemed to breath equally during my comparison in 50% humidity and 55 degree night time temps. The careful design of the Mtn. Hrdwr. bivy seemed to be more waterproof, versatile and comfortable. On my recent Sierra Trek, I liked the full length side zipper (opposed to a shoulder zip) that matches any post 1998 #8 YKK zipper. It made sleeping more comfortable because I was able to open the zipper at my feet or head to cool & vent efficiently and I could get in & out more easily. The hood fit snugly around my bag's with a drawstring cinch (as opposed to a zipper). The M.H. bivy's seams are taped and the floor is much more waterproof than Nextec's fabric. I would recommend adding the scant 9 ounces for the extra comfort & protection.

Thought that by buying another bivy at almost twice the price would be better. I was wrong. Full zipper makes for an easy in or out, and good ventilation. A nice security blanket for your down bag during a wet Sierra storm.

This thing has become my sleeping bag’s new skin. Just zip it on and never worry about water again.
I've used it in the winter and summer in the mountains and on the coast. This thing makes your down sleeping bag rock solid.
One thing I learned is just put it on your bag before you leave and save some room in your pack.

The Conduit SL Bivy kept me dry, except for my face or whatever part of me was not tucked inside. If I had a second chance, I would purchase a bivy that kept the bivy off my face.

I bought this Mountain Hardwear bivy this weekend. I was so smitten with it that I had to sleep out on my lawn just to test it out. I like almost every thing about it. I can zip it onto my bag and put it in a stuff sack. I can thrown my sleeping pad in between the bag and the bivy, and it dosn't move around at all. If your into the whole ultralight minimalist approach, it is a great choice. It is as light as a tarp but with the protection of Gore (not Al, Tex). While sleeping out on the lawn I couldn't help but think what happens if the sprinklers come on or it starts to rain? With this bivy you can't really close up the face area, which is why I ultimately gave it a 4 instead of a 5. If you're thinking of getting a bivy, I think this is a great one, especialy if you're still learning how to live in a bivy--I think this can be a great learner.

I used this bivy during a recent missions trip in Patagonia. We were in the mountains most of the time. I slept in a wide range of weather out in the open and never had a problem with the bag. It got down to the low thirties and a normal Patagonia wind of 20-30 mph sustained and I was warm and never felt the wind. I strongly recommend this bag!

Used in the Wind River Range with a 25 degree Big Agnes Bag. I stayed warm and cozy down to the low 20's with no other shelter--even with frost on the outside of the bivy. The only drawback is that with my Big Agnes the ground pad fits in the floor of the sleeping bag. I love that normally because I don't slide off my pad, but with the pad inside the bivy, the fit was too tight so I had to separate them. Not a big deal though.