Bivy Sacks and Bicycle Touring

Matthew Jarvis enjoys backpacking and some interesting bicycle touring adventures. Combined with his experiences working with mountain rescue teams he has accumulated a lot of knowledge about wilderness camping in general and bivy sacks in particular. He has been kind enough to contribute this article to Bicycle Touring 101.

A bivy sack is a small, one person shelter which is more like a sleeping bag cover rather than a tent. In a lot of ways it is just a big waterproof tube you stick your sleeping bag, mattress and yourself into.

Matthew Jarvis using a bivy sack while 10,000 feet high on Mount Hood, Oregon.
Click to enlarge.

If you want to travel light and fast, they deserve consideration.

Pros

Lighter weight than a conventional tent. They often weigh in at less than 3 pounds.
Smaller ‘footprint’ – you can set it up in much less ground space than a tent
Ease of setup

Cons

They don’t have much extra room in them for changing clothes, reading or other activities.
Sometimes they don't 'breath' very well and can get clammy inside.
You, and only you, are going to fit in one. It's solo only (but read below).

Commentary

As I said above, Bivies can be great for when you want to be in and out without a lot of fussing around with a tent. In mountaineering we used them as emergency shelters or for base camp use when at elevation. I have used them in deplorable conditions, but slept very well at 15 degrees and 50-75 MPH winds at a wind chill of brrrrrrrrrrrrrrrrr .... so they work....

To set one up, you pretty much just have to roll it out or unfold it, stick in your sleeping bag, crawl in and you are sleeping.

Some come with a small pole that you use near your head to keep the material off your face and to get rid of that claustrophobic feeling. Others also have a small pole that does the same thing around your feet.

The material used in these can make a critical difference in what sort of environments they are best suited for. The Bibler Tripod Bivy, for example, uses a waterproof membrane material that is second to none in performance. That's great at 15,000 feet where the air is cold and dry, but not so great (generally speaking) down at normal altitudes or in wet, rainy or humid conditions. The humidity and your own breath from condensation can have you swimming inside the thing pretty quick.

Outdoor Research makes a very popular bivy and were the first to use the pole design around your head. They also make a version (or at least they used to) for two people. But at that point you might want to consider a tent given the limitations on space and the additional weight. Sorry, but you can't mate two regular sized bivies together like you can with sleeping bags...

The pole around your head makes a huge difference to a lot of people, and I would recommend that you consider these types as your first choice. Yes, they tend to cost more but the extra headroom and ventilation more than make up for it. You've worked too hard today for a crummy nights sleep, don't you think?

Bivies with poles usually have a feature that allows you to open them up at the top to enjoy the stars or to get some extra air. Good ones also have bug netting, and you can stow it away when not needed..

The length of the zipper and its' placement can be something of an issue - at least it was for me. Some bivy sacks have no zipper at all really, you just have to sort of wiggle your way into them from the opening at the top. Others have zippers that run down the side and help with getting in and out quite a bit.

The ones without zippers are lighter and simpler, but getting into one, with a sleeping bag already inside, sitting on the ground (wet, snow) is not my idea of fun.

Some even come with arm holes so you can sit in the thing and do camp chores, all the while being warm and toasty and protected from the elements.

Remember when shopping for a bivy that the required length isn't just your own height, but you need to include extra for the foot section of your sleeping bag as well as plenty of room for your head. There's nothing quite as unpleasant as trying to sleep in a space that is 4 inches too small.

Some bivies have enough room inside for your sleeping pad, while others have attachments that let you hook them onto the mattress. I always just used the bivy on top of the mattress, but that was always in snow. Rolling off wasn't such a big problem because the whole setup kind of made a depression in the snow anyway which tended to hold me on top. On normal ground, rolling off and going Thump! in the middle of the night might be a problem for some.

Cost

You can pay as much as you like for a bivy sack. I've seen cheaper versions for as little as $50, and the top end (such as the Bibler) pushing the $300 range.

My Bicycle Touring recommendations

I'm not an expert on cycle touring, but given what I DO know about it and my experience with bivy sacks, I would make the following recommendations when making a purchase:

Get a bivy with a pole for added head space.
The longer the zipper for ease of entry, the better. Yes, this adds to the "more things that can leak, break or go wrong" factor, but well worth it.
When in doubt, get the bigger size.
If I *had* to recommend one brand of bivy, I would go with the Outdoor Research Advanced or Deluxe Bivy. You really can't go wrong with the design and quality of construction.

Outdoor research and Mountain Equipment Co-op (MEC) are two web sites that have examples of bivy sacks.

Submitted by Matthew Jarvis

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