permanentjaun

I'm considering an ultra-lightweight option for my next tour. On my first tour several years ago I used a bivy. It was great and relatively lightweight. It was, however, still a bulky item on the bike that also took a little time to set up. After a long day on the bike, and with the sun setting, it could become a cumbersome process.

For my next tour I want to use the Adventure Cycling routes to insure I have a safe route through scenic parts of the country. I'd like to do it on my road bike and see how fast I can do it. This will involve stripping down to bare necessity. The bivy has to go.

My idea right now is to use a reusable emergency bag like this one.

https://www.vtarmynavy.com/heatsheets...ency-bivvy.htm



The website calls it a bivy, but it looks to be much more like a sleeping bag than a bivy. It doesn't have any top. That product would be an obvious weight and space saver. A lightweight bivy is around 2 lbs. This would be 1/10th of that and be much smaller. It would also be a lot quicker to set up at night since there really is nothing more than taking it out of the bag and getting in.

The only problems I see with it are that it wouldn't protect you much from insects. Does anyone know if a material like this would allow a zipper to be sewn into the opening to prevent insects from getting in? Do you all have any other ideas to prevent insects?

Thanks,
Matt

dennyd

i would test this thing out before relying on it on the road. I once wrapped up a sleeping bag in one of those metallized emergency blankets and woke up soaking wet. They do not breathe, and water condenses on the inside if it is cold on the outside.

mr geeker

devils avocate here... i say go for it. if thats what you want to do, who are we in our infinate wisdom to stop you?

gpsblake

not only do they not condensate but they are also very noisy to sleep in. As someone else suggested, try sleeping in one on a humid night and see if it is for you.

permanentjaun

The condensation problem worries me more than the noise. My bivy on the last tour wasn't that quiet. It had a rain layer that would make noise by rubbing against the inner layer if there was the slightest breeze.

gpsblake

Another suggestion is to visit the Appalachian trail forums at whiteblaze.net Those guys thrive on specializing on ultra-light gear and are the experts on it. Amazing some of the ways they will cut weight, like shaving off toothbrushes and such. Best wishes.

nun

Condensation is the biggest issue that I see. I've slept in a Thermo-lite emergency bivy and always ended up with a damp sleeping bag even with the foot vent open.

njkayaker

Probably not very durable. Expect to replace it frequently.

Allen

Emergency bivvy.
It will get you through the night but is not intended for day to day use.

Allen

Emergency bivvy.
It will get you through the night but is not intended for day to day use.

MichaelW

We call that a survival bag. It is std equipment for any hiking in the hills in cooler months. No-one would plan to spend the night in one.
You are probably better off with a tent-tarp arangement. I have used an army style "basha" in the Uk and as long as your bag is warm enough, they are good. US style tent tarps are a bit more sophisticated.

mijome07

https://www.bikepacking.net/reviews/s...mergency-bivy/

prathmann

I've used one of the aluminized Mylar bags as a vapor-barrier liner inside a sleeping bag to extend it's temperature rating. My sleeping bag is a 2 lb one that's rated to 20F and with the metallized plastic liner I've comfortably used it down to about 0 F. But I can't see using such a bag as a replacement for a bivy or tent.

I second the suggestions to try out whatever ideas you have on some close-to-home outings with backup options readily at hand.

spike57

I have a goretex bivy sack--weighs just less than a pound but it is durable and will last multiple nights. I wouldn't want to spend multiple nights in it, though. For ultralight info, check the forums here: https://www.backpackinglight.com/cgi-...ums/index.html

None of these guys seem to use a bivy. They do really well with tarp tents. There are also some great entries on Youtube featuring tarp tents.

Bacciagalupe

Dude. Seriously.

Emergency bivys are not designed for regular use. It's made for very infrequent use, not as a real shelter.

A real bivy is almost as basic a shelter as you can get -- and it's even too basic for some situations (due to condensation). Many bivys weigh about 1 lb, not 2, not as though you would even notice without a scale. A tarp is simpler but will be just as bulky and the same weight.

Doing a fast and light tour is one thing. But if you can't make room on your bike for the most basic of necessities, it seems to me that your priorities are slightly off, or you need a SAG van....

LeeG

I'm sorry but this doesn't make sense.

burtonridr

I had to sleep in one last June, in the mountains here in Idaho. It was the worst sleep I have ever got while camping. It got down to around 30 degrees that night where I was sleeping and that thing kept me barely warm enough. +1 on the noisy and lots of condensation. I woke up probably 4 or 5 times to turn it inside out because it was wet.

Plus side, it keeps you alive.

Downside, they are miserable to sleep in.

You can get ultralight weight synthetic or goose down sleeping bags for 40 degree nights that weigh next to nothing and pack down to the size of that emergency bag.

SteakKnifeSally

While I have not slept in the bag you mention, a friend tested it for a survival camping trip in the boundary waters. He thought it would be ok down to 50 or so, but ended up with a down ultralight bag instead. Please let us know if you try it.

Personally, I'm planning on a synthetic ultralight bag, bulkier than down, but better in a hammock because it compacts less.

markf

That looks a lot like the space blanket that my partner took on an overnight climb years ago. It kept him warm through the night, but it was falling apart by morning.

How about an ultralight down bag, a closed cell foam pad and one of these:https://www.blackdiamondequipment.com...ightsabre-bivy ?

denver_whitest1

As others have mentioned, this is because its a vapor barrier. if these are used propperly, they can keep you very warm, however if you use them impopperly, they can be very dangerous because you will get cold, fast.

If you want a lightweight tent, look into a 1 person tarptent or a zpack hexamid made from cubin fiber if you have the budget. if you are wanting something sub-1lb and you're not going to be dealing with much rain, get a inexpensive bivy sack from REI or something.

Bekologist

siltarp, a Black Diamond 'winter' EPIC fabric bivy and a bug net is what you want.

Ive used a thermolite bivy on ultralite trips and, like the others, felt the condensation was a deal breaker.

the Adventure medical kit thermolite bivy is actually fairly durable, much more durable than the foil emergency bivies. mine withstood saveral litter packagings of injured mountaineers and served me well until it went to the hospital wrapped around some skier with a broken leg. got a new one as the AMK bivy is the best i've found.

TBatty

I have used the "bivvy" the OP pictured. It breathes better, and is quieter, than the mylar "space blankets". It does not, however, provide much warmth. I've spent ten years as part of a search and rescue team in Oregon, so I've done a few nights out that were not entirely planned, and the item the OP asked about is okay in mild weather as a better than nothing option. I would use it as a primary sleeping bag. Many of the other posts have it right, an ultralight down bag and tarp, with a 1/2 to 3/4 length sleeping pad underneath would be my ultralight option.

emarg0ed

I used to use these often when I was doing backcountry hiking in Alaska, when I was going fast and light during the summer months. They'd never last more than a few nights at best. You'd have to buy 50 of them to do a tour, which is silly. Something like that Black Diamond bivy would work better..

TBatty

I need to proofread. I meant I would NOT use it as a primary sleeping bag.

cburnett

If you want to shave ounces from shelter.... consider reading threads at

www.backpackinglight.com
visit
www.mountainlaureldesign.com -- makes really light bivy
www.sixmoondesigns.com
https://www.titaniumgoat.com/