Lighter than a tent and almost as comfortable.
When you're planning on sleeping in tough conditions but aren't interested in carrying a tent, stick the Rab Alpine Bivy in your pack. It weighs only a pound and packs down to the size of a water bottle, so you'll never have to leave essential gear out of your pack to bring it along, and it zips up all the way to offer full protection from the alpine elements. The eVent 3L waterproof and breathable membrane keeps water out and prevents condensation from building up inside, and the tough nylon floor stands up to rough ground when you're sleeping in less-than-perfect conditions, so you won't wake up with your butt in the snow.
- Event 3L waterproof and breathable membrane
- DVStorm fabric
- 70D nylon floor
- End zip entrance
- External zipper storm flap
- Q & A
Best. Bivy. Ever.
- Familiarity: I've put it through the wringer
I am a huge fan of this bivy. I tested two other ones aside from this one -- the outdoor research advanced bivy and the MSR AC Bivy -- and the Rab alpine bivy outperformed both of them. As a little background about myself, I am from Arizona and have never really needed or been a big fan of tents -- My friends and I refer to them as "oppression tarps." As such, I always sleep out under the stars in just my sleeping bag and I did just that when I went to Smith Rock State Park for the first time to climb. For those of you who do not know, the winters at smith are brutally cold and CRAZY frosty in the mornings. As a result, the first night I spent there was the most miserable night of my life. I woke up with frost on my bag and shivered the whole night through. I promised myself "never again" and started looking into bivies.
Bivies seem to be either huge and roomy, like the outdoor research alpine bivy, or compact and ultralight, like the MSR AC Bivy (though the AC Bivy was pretty huge on the inside!). I think that if you are going to carry something that is 3 pounds with you, then you might as well look into an ultralight tent. Bivies are meant to be as minimal as possible, and thats exactly what the Rab AC bivy is. It weighs about as much as the AC bivy, but is infinitely more breathable. The first night I used the AC bivy, I woke up with my nice down sleeping bag soaked through from condensation and I was furious that a company as reputable as MSR would sell a product made of materials akin that of trash bags. Ventilation is key when avoiding condensation issues and I returned it the very next day. I then decided to try out the Outdoor research alpine bivy because goretex is a highly breathable material. It was really solid and roomy, but it does not pack down that well and weighs a lot -- which I think defeats the purpose of a bivy. I ended up with a little bit of condensation on the inside of the bivy after testing it out for a few nights, but nowhere near as bad as the AC bivy was. I decided to return the OR Alpine bivy because of its size and did some research online about optimally breathable materials.
My attention was eventually caught by eVENT fabric, which is apparently more breathable than goretex while remaining similarly waterproof. There was a great review of an entirely eVENT bivy by company named "integral designs," and that company has since been renamed Rab and is based out of the UK. Rab is not very prominent in US markets and I had not heard of the company until I found this bivy. I was initially hesitant to buy one of their products, but after MSR and OR disappointed me, I decided to give this product a try. I have to say that I am completely blown away by how awesome this bivy is. Its light, compact, and has no wasted or excessive features all. It really is nothing more than a highly breathable, light, and waterproof sack meant for sleeping. If you are claustrophobic or want something that is big enough for you and a lot of gadgets, then this bivy may not be for you. If you are a seriously minimalist hiker or alpinist looking for a bombproof bivy to add to your sleeping system, then I could not recommend this product enough.
For reference, I am 6 foot 2 inches, 165 pounds with a climbers build. I have no problem getting into this bivy with a therm-a-rest NeoAir X therm sleeping pad and a super lofty sleeping bag, but its definitely a snug fit with little room to roll around. You could maybe squeeze tomorrow's clothes and a water bottle in there with you as well.
Oh and this product also looks really cool and has glow in the dark tabs on the zippers, which is nice when you have to answer the call at night but don't want to turn on your headlamp. I really cannot emphasize how great of a bivy this is and how excited I am to use it in the years to come! Thanks Rab!!! You've definitely made a lifelong customer out of me.
Rab & eVent
At Rab we use eVent waterproof fabrics in some of our core shell products. These products, such as the classic Latok Alpine Jacket, are specifically designed for use in the harshest and wettest environments in the world.
These fabrics are extremely hard-wearing and durable, however they combine a range of unique technical features which allow for high levels of moisture movement and breathability. With these benefits, you can wear eVent waterproof products for fast moving activities without overheating.