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Outdoor Research
Alpine AscentShell Bivy

3.5 out of 5 stars
12 Reviews
Current price: $224.21 Original price: $298.95
25% off



Why We Like The Alpine AscentShell Bivy

"Less is more" doesn't always ring true, but the Alpine AscentShell Bivy packs as much as possible into a small alpine shelter. On our lightest ascents into the wilderness, this bivy offers serious protection in all four seasons. Outdoor Research's Helium AscentShell membrane keeps us secure in unruly weather, and it boasts breathability that ensures our outdoor comfort during the hotter months as well.


  • Four-season bivy for alpinism and solo backcountry adventures
  • Helium AscentShell floor and fly keep rain, wind, and snow at bay
  • Mesh screen allows more airflow on hot summer nights
  • Large, step-in opening offers easier, more comfortable entry
  • Single pole design makes setup fast
  • Packed only weight barely exceeds one pound
  • High volume toe box and extra headroom for gear storage and roomy comfort
  • Item #ODRZ8NB
Responsible Collection
Bluesign Approved
[membrane/laminate] Helium AscentShell (3-layer), [face fabric] (fly) 30D nylon, PU coating, (floor) 40D nylon, TPU coating
mesh canopy
fully sealed
Floor Dimensions
83 x 28in
Floor Space
79 x 32.5 - 22 x 19in
Packed Size
3.5 x 12.25in
Trail Weight
1lb 0.8oz
Packed Weight
1lb 2.6oz
mountaineering, backpacking, ultralight backpacking
Manufacturer Warranty

Overall Rating

3.5 based on 12 ratings

Review Summary

1 Stars - 1 reviews
2 Stars - 2 reviews
3 Stars - 2 reviews
4 Stars - 4 reviews
5 Stars - 3 reviews

What do you think about this product?


Selecting an option will reload the available reviews on the page
1 out of 5 stars

March 14, 2024

Major Flaws!

I will say, this is a decent bivvy but the issues I have experienced (especially when cost is factored in) bring it down to a 1 star review. I do have some positive things to say as well so lets start there. THE GOOD: The material is durable, easily rolled up to the same size as my Nemo Tensor inflatable pad and lightweight. I like the mesh and zipper system, helps to regulate moisture even when 20 degrees out. I was using this mostly in shelters within the Smokies. I cannot speak to waterproofness but it seems like it would get the job done, especially with a tarp/fly. THE BAD: For context I am 6'1'', 230 pounds. The difference in size between the Helium and Ascentshell is +1" in total length and +2" shoulder width. I don't think any R&D was done or it would have been quickly found out there is not enough room for a winter sleep set up. Which is ironic since it is called "Alpine". My biggest issue is the tacky/poor quality pole that it comes with. After my 4th time using it, I started to notice splintering in the female parts on the pole. I do not trust using this product without it breaking on me. I am now looking into using a 3rd party to build me a better pole before I return it. Another big issue is the toe end of the bivvy. It is SO small, my down quilt was being compressed and my feet would get cold unless I wore my booties and heavy socks. If you are a back sleeper, you can kiss having your toes pointed up goodbye, luckily I am sidesleeper but even ankle over ankle was a little claustrophobic. If it weren't for the price, I would give 2 stars. However, for the price, I can't justify giving more than 1 * since I feel these are MAJOR areas that should have been improved in the first place before calling it "Alpine". Overall, if you are a bit smaller than me and open to getting a better pole then this thing is great to have. If I do find a pole, then I will be bringing this bivvy with me on my AT section hike this May.


Originally reviewed on

5 out of 5 stars

January 8, 2024

Comfortable Bivy

Great protection and solid breathing for a bivy. The longer door gives me better ventilation and bug protection than my other bivys.


Originally reviewed on

4 out of 5 stars

January 5, 2024

Probably the best bivy option out there

Have taken this out a couple times and so far I will say I'm happy with it. The stakedown loops are pretty bogus, I ripped the one off by the foot box in my sleep, thankfully the seams were taped on the inside so I had my Ma sew the seam back together and now it's good to go, minus the loop. The arch in this bivy is what does it for me. Bivvies are usually just claustrophobic in general but this one is manageable. The blue colored shell itself doesn't seem to collect moisture, but the trim parts that are black will collect moisture. I have woken up a couple times to find it coated in light ice on the inside of the bivy. Overall I am very happy with the purchase and look forward to using this year round.


Originally reviewed on

4 out of 5 stars

October 19, 2023

Nice but tight

Good concept, but more space on the lower end would make sense - both practical for using a 25" mat or to store some additional equipment. Humidity is not a major problem, but please could you give a Moisture Vapor Transmission Rate for the bivvy? Thank you!


Originally reviewed on

3 out of 5 stars

August 6, 2023

Some good features, some needs improvement

Used it as a minimalist sleeping system in 50F in semi arid Utah. The asymmetrical headroom and zip system seem to work well, bug screen worked great too. Only complaint is the foot room is tight when used together with my 20" wide x2" thick inflatable sleeping pad and sleeping bag. I'm 5'11" and 200 lbs and there's barely any leg room. Description recommends a sleeping pad no wider than 22" but I think it'll work best with a tapered sleeping bag. Hopefully next version would have a little more legroom then it'll be golden.

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Originally reviewed on

5 out of 5 stars

August 1, 2023

Great material

[This review was collected as part of a promotion.] This bivy has the protection you need in the size and weight that you want.


Originally reviewed on

2 out of 5 stars

September 29, 2022

Probably not keeping it

This is not a full review, but an initial reaction to what I consider a really poor design. I got this as a replacement for the previous generation of the Helium bivy that I'd had out on several bikepacking adventures in CA from 8k' at freezing to warm summer redwood forest trips. That model had 5 stake out points and I'd used kam snaps to keep the zip-able head portion of the top rolled up for better air circulation. I didn't get bad condensation if I had the proper temp quilt for the climate. I could fit a rectangular Neo Air All Season pad with a 20º down quilt no problem. So I decided to "upgrade" to the Alpine AscentShell bivy, mostly for the new zip style, but calling this an "alpine" bivy is a bit much. I'm 6' 180lb. and my feet would be wrecked in freezing conditions. I'm a side sleeper and even then, crawling into it with that same Neo Air pad and a 40º down bag, there was a lot compression happening. If I were to sleep on my back, my feet would fully compress the down. It also needs more tie down points, like the current Helium. Not sure if the roll top lop can be used to guy up the mid section of the bivy, but if I keep it, I'll consider adding other points with Tenacious Tape and shock cord. Overall, the headspace feels less claustrophobic than the Helium, but there's not pocket like the Helium had. And I must say, it's way easier to get into and out of than the Helium. If you're going with an UL tapered air pad or a foam pad, you'll be alright, but this is definitely a 2-3 season item for anyone north of 5'10". (I've also had the GoreTex Alpine bivy, so I've got some experience with OR's bivy options) Again, this bivy hasn't seen the outside of my house, so no real world experience, but it will probably stay that way.


Originally reviewed on

3 out of 5 stars

September 26, 2022

Emergency shelter

I have this in my 24 hour pack for search and rescue as an emergency shelter. I have slept a couple of nights in it, in alpine conditions in the summer where it drops to about 7 degrees Celsius at night and both times I woke up with lots of condensation inside. You need to fry your sleeping bag and everything inside and this was with the vent opened completely about 1.5 feet, so tons of ventilation. Not much room for extra gear just your cellphone/radio/water etc. I am not sure if I would buy it again and I don't have anyone I would recommend it too but i am glad I have it as back up as it still beats sleeping under a tarp.


Originally reviewed on

4 out of 5 stars

September 22, 2022

Great Bivy with issues

I'm a Bivy Sack fan. The Alpine bivy has been my favorite, other then the entry so I picked up this one, everything about it is great but I got it for extreme conditions/cold weather and it is very tight with a insulated pads depth, I use a full xtherm mat.I'm 5-10, with a full pad your feet get restricted. Make the sac with about 3 more inches of vertical volume please. Also, when you are Biving at 13000 feet on a ridge edge, the 2 attachment loops are questionable when you are not in the sack, it can catch wind underneath and your Entire shelter system cold pull of the mountain when you step out to take a pee In the middle of the night. A lot of potential or good for a petit person in 3 season conditions.


Originally reviewed on

5 out of 5 stars

August 1, 2022

Insanely Light

My new bivy is even lighter than my original auora bivy. Cant believe OR made an even lighter weight waterproof bivy. Customer service is always a 10 with you guys. I will be recommending to friends. Thanks OR


Originally reviewed on