Outdoor Research Alpine AscentShell Bivy Nimbus

2025-05-13T11:11:09

More generously cut than the Helium model. Breathability is pretty good.

TIMOTHY D.

2024-09-15T20:00:00

Went hunting and found myself sleeping in my truck bed during the rain. I had a lighter bag, but loved the breathability and weather proofing. Massive improvement from previous generations; I would highly recommend upgrading!

Bro

Originally posted at

2024-08-28T20:00:00

I got this bivy for solo expeditions in the Alpine Lakes Wilderness. It's been a fantastic piece that withstood a tree branch falling on it (no one was inside it, thankfully!) followed by 7 hours of overnight rain. Great pack weight. excellent top facing, breathable mesh. The only thing i could think of is that this bivy should come in camo.

Ill D.

Originally posted at

2024-07-11T20:00:00

I've taken this on one trip and it was roomy and comfortable. Took a little adjustment to get the screen to stay off my face but works way better than my last one. Didn't test it in rain, fortunately. This was a replacement for a bivy I've had since the 90s and it started to fail so OR sent me a new one, amazing lifetime guarantee in action!

Natalia

Originally posted at

2024-06-20T20:00:00

The weight of this bivy is phenomenal when compared to full body tents. At 18 oz (1lb 2 oz), this breathable (albeit ventless) shell is a great alternative to a heavy weather proof tent when you know there will not be inclement weather. With only 3 stake points, one pole and the body (no footprint needed), you will never notice this piece in your pack. The set up is rather quick and easy. Inside, you may feel cramped but once asleep, you won't notice. I was able to store my shell jacket, shell pants, a book, a towel, warm gloves and a puffy and STILL had plenty of headspace. I use the Thermarest NeoAir XLite Max SV. This a rather wide sleeping pad and still fits nicely in the bivy. So if you are concerned with your pad fitting, if it's smaller than this you will be fine because any bigger may not. The ugly: throughout one whole night of rain in the backcountry of Ouray, CO the inside of the bivy was dripping and coated my sleeping bag with a nice layer of moisture. Since my bag is prepared for that (dri-down and DWR coating), I myself was never wet and slept through the night. Immediately when you open the bivy, if it's raining, the rain will enter your sleeping space since there is no vestibule. Overall, I think the construction for the weight, breathability and ease of set up/take down, leads me to recommend this bivy for "dry weather backpacking" to any ultra light adventurer.

Capt P.

Originally posted at

2024-06-08T20:00:00

I used the bivy at Mt. Baker last week and I was totally comfortable. Granted that it was in quite good weather with moderate winds. I'm 5 foot 7 inches and 135 pounds there was ample room for me and 10F sleeping bag and some of my gear. In a pinch I could have brought my pack in as well and kept it above my head. Overall super happy. If there's a complain I have to pick, it would be that the zippers don't feel as durable as the rest of the bag - I haven't broken them and in use it seems to work without issue, but they don't give the sense of durability like the rest of the bivy. A more durable burly zipper might impact packability a concern so may be a trade off was made. Lastly, Outdoor Research stands by their Infinite Guarantee - this is not just marketing. When my old bivy developed issues, without question it was replaced.

Sarath

Originally posted at

2024-03-05T19:00:00

Sold as advertised. Built with quality. Tried this bivy out on a weekend trip and I was really comfortable in the rain. Wasn't a downpour so I would like to try it in those conditions. I fit a sleeping pad and bag inside and I was cosy. Packs small into its own stuff sack and doesn't take up much room in your pack. If your thinking about getting this..just do it already.

D S.

Originally posted at

2024-01-07T19:00:00

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

David

Originally posted at

2024-01-04T19:00:00

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.

QuietBison

Originally posted at

2023-11-28T19:00:00

I would recommend this over the helium. Yes the alpine is a little heavier, but in every way it is a direct upgrade.

Jayden

Originally posted at

2023-10-18T20:00:00

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!

Markus

Originally posted at

2023-08-08T20:00:00

This bivy is amazing. Can't have better than this : small weight but amazingly waterproff. I recently woke up in 1.5 inch of water in a heavy rain and I was entirely dry. Perhaps I would have a few upgrade for the next gen : would be nice to have a little bit more space arpund the head (I'm 6"2 and it's perfect for summer, but limit for winter because of the bag), about 4 inchs longer would be perfect. It would be nice to be a 2 inches higher for the foot too so the winter slleeping bag could be more expand.

Dave

Originally posted at

2023-08-06T20:00:00

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.

Russ

Originally posted at

2023-07-31T20:00:00

This bivy has the protection you need in the size and weight that you want.

Dan

Originally posted at

2022-09-26T20:00:00

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.

Hayden

Originally posted at

2022-09-21T20:00:00

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.

Ben

Originally posted at

2022-07-31T20:00:00

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

Tyler

Originally posted at

2022-06-16T20:00:00

So far I love this bivy! I have been using it on the pacific crest trail and so far it's been amazing. I'm 5 foot 8 and it fits me just fine with lots of room to turn around inside. My only problem with this bivy is that the loop for staking the head area just ripped right out? I've only used the bivy 5-6 times and that's all it to break the stake loop. Now that it's gone the front falls down. I'll either be sending it back to be repaired or super glueing a loop back to make it usable again. Disappointed that it broke but I'll be happy once it's fixed.

Woods

Originally posted at