Select recommendations from experts who use this product

Great sleeping bag except...

Holy smokes does this bag shed feathers! I'm really hoping that it's just a new bag thing and eventually it stops. I'm getting tired of my tent looking like a chicken had a hay-day and picking feathers off my clothes every morning. Aside from the shedding, it's a cozy warm bag. I'm a side sleeper so I like the top zip style and double zipper. It's more compact and lighter than my previous bag, saving space and weight in my red bag.

I have been using this bag for a year now and have spent roughly 50 nights in it. It is great for summer and warm weather camping. The pillow barn is fantastic for keeping my pillow in place. It packs down really small. I am 5'6" and it is just the right length. It is great for side sleepers like me who tend to roll from side to side during the night. There are a few not so great aspects. It is rated at 20 degrees, but I get super cold using this if it is below 50. The zipper gets stuck almost every time I zip or unzip it, although I don't know if this is common with down bags. It does shed a lot of down. Every time I use it there are feathers in my tent and pack.

This sleeping bag was incredible. Very warm and comfortable for a side sleeper. If you toss and turn a lot III is a little restrictive. Not more so than any other mummy style bag. The pillow pocket is a little gimmicky but effective. I think if you really know how you like to sleep this is a terrific bag. I wouldn’t recommend it as a first sleeping bag purchase just because of its niche sleeping arrangement.

Super comfortable and warm sleeping bag. Perfect for side sleepers and switching from side to side. The pillow sleeve was a little awkward to keep shifting the pillow, but it did keep the pillow in place instead of sliding out from underneath your head every 30 minutes.

Excellent Solution fro the Side Sleeper

The Sidewinder SL is now my go-to bag for just about any adventure. A lifelong side sleeper, the configuration of almost every mummy bag on the market technically worked for me, but always made for constant shifting, tossing, turning, adjusting, etc. The Side winder just makes my sleep out in the field that much easier. I've also been very impressed by the warmth of this 20 degree bag. I would say it is a rare example of a bag that truly delivers the warmth of it's degree rating. And big agnes inclusion of both a stuff sack and larger half mesh storage bag add some nice value. I couldn't be happier with the Sidewinder.

Not for big people

Ok so I'm a big boy, 5'10 285lbs, 42 jeans. So getting into the damn catagory. This sleeping bag, packs down pretty small, definitely seen smaller. Its pretty light, the bag is very thin feeling, but when a thick boy tries to get into the bag. Yeah i fit, but its a bit snug for the round body. You can roll around still, but not gonna be rolling around in the bag, it's if i had a comparison, I'd say its like sleeping wrapped in weighted blanket. Which is a weird feeling being its a lightweight down bag. Does ok for condensation, didnt feel wet inside while sleeping in my gortex military bivy. So if your like a 38 inch waist, its probably gonna be nice for you. I next time, will be buying that xl bag BA offers, i forget the name.

The material has held up through several camp trips; the zipper is very sturdy. Absolutely love the down and it keeps me cozy when it gets chilly at night.

Lightweight and warm, used car camping on a night that got down in the 30s. I am a side sleeper and this was very comfortable to sleep in. The only 'downside' was that it shed down feathers all over my Exped Megamat and was hard to clean up because they stuck to the material on top (this is my first sleeping bag of this type, so maybe this is normal?). Now I just cover the Megamat with a bedsheet and that has solved the problem.

Very comfortable and warm

I used this on a bikepacking trip and the sleeping bag was comfortable and warm. Not sure if it will work at 20 degrees as stated but I slept in 50 degree weather and it was comfortable.

Awesome bag for side sleeper!

This bag is a game changer for side sleepers! So much more comfortable than traditional bags. The pillow pocket is great for keeping a jacket in place to improve your comfort.

Great sleeping bag

I use this sleeping bag while hammock camping. I have used it several times with my 30F rated underquilt in 20-40F conditions, snow, rain and shine. So far I have not been able to sleep without sweating and unzipping it every time. The sack it comes with has kept it small enough to fit in my pack along with all my other gear, I’d imagine with a synching stuff sack it can get even smaller. Foot box has kept my toes warm every time. My only “complaint” (slight inconvenience) would be that the pillow holding compartment has a fairly narrow entrance. I have to put the inflatable pillow in the compartment while still delfated, then awkwardly inflate it while it’s in the compartment so it fits in there. Then awkwardly deflate it before taking it out so it fits through the narrow entrance. Kinda weird but it’s a crazy warm bag so who cares.

Great Bag

The bag is roomy and warm. The zippers work well for me so far. I have mostly used it hunting from a base camp in September and October, but overnight lows were in the 20s.

Fantastic Side Sleeping Bag

Pros: - Extremely lightweight - Packs down very well - Well built/great materials - Works better than the 4 other bags I’ve tried as a side sleeper. - Comfortable with copious amounts of room(long bag) almost to the point of no “mummy” constriction - Epically fast shipping(through ExpertVoice at least) Cons: - For a 20 degree rated bag, I needed lots of layers to stay warm at 35 degree ambient. I may update once I’ve retested it with the wool liner(another $100 expense and extra pound pack weight that shouldn’t be the expectation of a 20 degree bag in 35 degree weather). - The “long” size is nearly too long for me @ 6’ tall - Zipper gets snagged too easily (to be fair this is an extremely common sleeping bag issue) - The pillow pocket is useless with any blowup style pillow. I have to sleep with it outside of the bag. Works ok with bunched up clothing though. If I were to reorder this knowing what I now know, I would have rather the “normal” length bag(again I am 6’ which is the max recommendation for the “normal” length. All-in-all, I am fairly satisfied with this bag!

Finally a great night's sleep!

I'm 5'9", 200lbs with broad shoulders. I got the long because many said these were short bags. I like the length but at 69" I could have gone with the short. I've used this for 8 nights so far ranging from 30⁰ to 44⁰ and along with a BA Rapide SL I was warm and incredibly comfortable side sleeping through the night. 8 night isn't long enough to test longevity but I don't see that being a problem.

Side Sleepers Wish Come True

This bag was warm and roomy. It only got down to about 30°-40° F and I stayed nice and warm. I am right at 6ft tall and fit fine and had room for a small inflatable pillow in the hood of the bag. If you are a side sleeper this is the bag for you.

A warm and comfortable sleeping bag!

As a routine side sleeper, I found this sleeping bag to be very comfortable when in the side position. There was no problem at all from a warmth perspective , but typically use it at temps just above freezing (so take that into consideration). The only thing that could be improved (in my opinion), is the zipper. While it zips easy when outside the bag, trying to zip up fully when inside the bag takes some effort. All in all though, a very good product.

Excellent bag

Love how lightweight, roomy, and warm this bag is. I have only used it in temps going down to the low 40's; however, this tent kept me very warm- and I am a cold sleeper. Also, being 6'2"/190 lbs with broad shoulders, it has MORE than enough length (I bought the longer bag), and plenty of room in the shoulders to accommodate my side-to-side sleeping. Doubled with the thicker Hinman pad, it was almost like I was sleeping in my bed. This bag packs small and is light enough for backpacking. The zipper rarely bound up unlike my other bags, and military issued sleeping systems. And is very comfy. I've used this for chilly rainy weather and took it with me for the annual RAGBRAI in 2023- 500 miles/7 days cycle ride across Iowa. Although, with temps in the 90s, I probably did not even need a bag. Nonetheless, being so light and compact, brought it just in case. The only downside is that it sheds occasional down feathers- but that is to be expected with smaller down, I would not take that away from a 10/10 recommendation.

Love it

BA hit a home run on this bag! Warm and allows you to sleep on your side, switching sides in comfort! Would definitely recommend for side sleepers!

Perfect for any side sleeper. Makes it much better for being on your side and having the head opening turned towards the side also. Would not recommend for anyone who rolls around a lot or who does not primarily sleep on their side as the opening is ONLY on the side and it doesn’t move with you as you roll. Very warm and well insulated!

I bought this for a very remote Yukon white water rafting trip as my other backpacking sleeping bag needing replacing. We camped along the rivers, Below snow capped maintains , and next to glaciers and I was more than warm and comfy.

Great for true side sleepers

The execution with this bag is great. Not flawless, like anything in life, but it's a great bag, and does what it's made to do. It is a fairly narrow bag, and the fill is mixed with no option for all down-filled. That being said, it packs down well with any third-party compression sack, and isn't too heavy. Not the smallest and not the warmest, but if you can get this on sale it is well worth the money. It's so good that I'm probably going to need a second one for my wife.

Fantastic so far

Have used this on a few overnight hikes, my 5 yo typically carries it since its much smaller and lighter than his synthetic. It's been great so far, I will admit its nearly impossible to fight off a 45lb shorthair pointer for it. I have used it down to 35 degrees and was a little on the warm side but it wasn't a problem due to the bottom "vent" zipper. I'll find out more about it in the coming months but would definitely recommend to others, especially those that sleep on their side, or sleep like me rolling around all night.

Awesome sleep

My sidewinder sleeping bag came in just in time for my 7 night rafting trip. I am a side sleeper and the bag was super comfortable and moved with me when I roll but didn’t bunch up like others. The best sleeping bag I’ve ever used.

Great bag, a tad large

Great bag, keeps me warm in colder climates, but it feels large and roomy with even the regular bag. Largest complaint is that no matter what I do the zipper pull tab was always falling onto my face when trying to sleep, so I have to unzip the bag several inches so it doesn't interfere. Fix the zipper issue and I'd give it 10/10!

Warm and Comfortable!

Used in the Colorado mountains during a multi-day backpacking trip. This bag was light and extremely warm. The design proved to be great for side sleeping and was roomy enough to fit an extra backpacking pillow between my knees to prevent hip pain. The foot box was warm and roomy. The bag packed well, also. Highly recommended for side sleepers. It’s worth noting though that the bag was equally comfortable when laying on my back so no worries there!

Comfortable, light, and warm

This bag is awesome and I find it very comfortable for tent camping/truck camping (I have not taken it into the backcountry yet). Its super comfortable when sleeping sideways as well as on my back (I sleep about 50/50 on my back or on my side). The only reason I have to take a star off is that it seems to shed its feathers more easily than my partners Big Agnes bag. Her bag also appears much fuller and fluffier than mine and it is rated to the same temperature specs and is also a down bag. My sidewinder looks rather limp next to her torchlight. Maybe this is how the sidewinder is and it has always kept me warm so far, but it concerns me for the future. I hope my concerns prove to be wrong as I would still highly recommend this bag.

I've sued this sleeping bag at a temperature near its rating and was cozy without being sweaty. The only drawback is the zippers are a little sticky. They may get better over time.

Great Sleep!

I used this sleeping bag for light bikepacking/car camping. The bag is well made and a great design, although perhaps a bit overkill for car camping. Because I have only had it for a short amount of time I worry about it's durability. That being said it is extremely light and packs down to a very small size. The sidewinder collection is a great addition to accommodate my sleeping preference, and it has lived up to every claim from BA so far. Only time will tell how durable the Sidewinder, but will continue to be the bag I reach for every time I head out for an outdoor weekend!

This bag ripped when I first had it out on my living room floor testing it near the head. Maybe I was a bit too rough when refolding it, unsure. But after this I've also had issues with a fair amount of down shedding. Not an unknown issue for down bags, but other Big Agnes bags have not shed nearly as much. I'm not very convinced about the overall quality of the fabric or stitching on this bag, however it is warm, and it is comfortable for side sleeping as advertised. Pillow loft and zipper are nicely designed. Four stars for quality control issues.

Based on five nights of camping while riding the GAP trail, this sleeping bag is very good. I am uncertain if I like Pillow Barn feature. Bag seems to be well constructed and durable and I did utilize the Big Agnes cotton liner to reduce the need to wash. While the zipper jammed a few times, I was able to unjam without damaging the fabric.

Love this sleeping bag. The lightweight bag is perfect for back packing and it offers plenty of room in the chest area. I can turn onto my side with ease. The zipper down the center of the bag is a game changer. I would recommend it for anyone who is a side sleeper.

As a sidesleeper, I always struggle in sleeping bags. This one just fits. The foot box makes the mummy bag seem roomier than others.

Used it once and it was good! I got the longer one for more comfort, so I am probably sacrificing a little warmth since there less mass inside but I don't really camp below upper 30s at night. Great for tossing and turning.

Love this bag

Used this sleeping bag while hiking the Colorado Trail. Kept me plenty warm every night and was so comfy. If it ever got very cold, I would just slip on some socks and temp would be great. Lost a little bit of down every night, bit I figure that's the case for an actual down bag. Down makes it pack down super small and super light. Would def take this on my next backpacking trip and recommend it to all.

Peerless Comfort

Took this into the colorado rockies with some friends for glamping, ended up having 8 very cold friends. I shared a tent with someone with a much larger sleeping pad, and despite being pushed into the edge of the tent, I slept through the night. That has never happened. In fact, I took this into my BED (unzipped) to toss over myself. My only complaint is the zipper on the inside can be finnicky with the insulated flap that covers it. I got it caught a couple times, but unjams easily.

I have been SO happy with this bag! It's cozy, super warm, really comfy. I haven't needed to bundle the hood down completely, but have been able to flip side to side without feeling tangled. I'm a 5'11" female, so I got the men's regular.

Temperature drop didn't affect me

I used this bag for 5 days packrafting on the Owyhee River, and it dropped down to 20 degrees. I had 2 sleeping pads with a combined R value of 6.5. The bag kept me so warm that I had to strip off layers to sleep. The ability to side sleep was really helpful, and it also allows for rolling back and forth. The only thing I would complain about is that it is hard to zip from inside the bag. The bag is pretty light, and using a compression sack made it smaller to fit in my pack.

Compact Cold Weather Comfort

This is perhaps the most amazing sleeping bag I have ever owned. Lightweight, very packable, but doesn't compromise on warmth and comfort. And if you're like me and switch sleeping positions several times per night, the Sidewinder moves with you with waking you to readjust the bag after you have changed position. An outstanding sleeping bag!

Side sleeper

Sleeping bag was extremely comfortable and warm. Have only used for three nights with temps in the 30s. Bag compacts into good size for backpacking with a stuff sack provided. I seen reviews that complained about the zipper. I had no issue with the zipper. It seemed no different than zippers on bags I have used in the past. I would recommend this bag to others. I would recommend this bag to a beginner or expert.

Fantastic Sleep

Grabbed this bag prior to a multi-day Yosemite hike where temperatures were expected to drop to around 30 degrees, which happened to be the lowest temperature of my older bag. Even though the bag is rated for 20 degrees, I found myself opening up the lower zipper to cool off a bit when temps were just below 30 degrees. Pros: - Pillow slot is incredibly nice, very easy to adjust from one side to the other when barely awake (Nemo Filo fits very well) - No cold spots when rolling around at night - Large foot box (Size 13M, no issues with wiggle room) - VERY comfortable near recommended lowest temp Cons: - Relatively bulky, even when packed down. - Relatively "heavy" at 1200g (or ~2lbs 10oz)

Warm, compressible

As a side sleeper, I was keen to try this bag. Overall, I slept well in it. It was warm and comfy. I'm not sure I'll use the pillow pocket long-term, but I gave it a try. I've only used it on one 3 night trip so far. I am a little concerned about the zipper, as it seems a bit delicate. I guess time will tell.

Solid option for the price

It’s not the lightest, nor most compact bag out there. However it performs very well at the price point. Being able to sleep on my side is a real game changer. I will gladly take the weight/bulk penalty because I sleep so much better. When I shift in my sleep, the bag doesn’t get tangled or clumpy, it just rolls right with me. Over a couple of backpacking and bikepacking trip, I’ve had really good success. Definitely worth it if you sleep on your side. Temperature rating seems about right.

Side sleepers heaven

Warm ,cozy and tossy-turny. I can sit indian style in this bag. plenty of wiggle room. lofty baffles. tested at 33F wearing Tshirt and shorts. good to go.

Love the design and intent of this sleeping bag. As a side sleeper this has been a game changer and I really love this bag. Reason for the lower score is that it is shedding a ton of down. Two weeks of backpacking with normal use and I probably lost over a handful of down. This is my first Big Agnes bag and not sure if I'll get another one at the rate its losing down. Other than that great bag love the design!

Leave it to Big Agnes to sell a bag that meets my needs.

I have recommended it to others and several have purchased the bag and feel the same as I do. It is not the lightest 20 degree bag on the market, but it is a great warm bag that has slightly more shoulder room for side sleepers who need to sleep with one arm “up” by their head. Bit too warm for summer months, but it is a fall/spring bag for sure. No issues with drafts and there is even a way to secure your pillow to the bag itself. This was the right bag for me. Glad I watched the videos about this bag and will recommend it in the future.

OMG!

Where was this when I spent decades in the field! As a side sleeper I was always breathing into the mummy bag through the night, and waking to a wet spot where my breath had accumulated through the night, but not anymore! Great bag for anybody who sleeps on their side.

Very good light weight bag.

Extremely comfortable for a side sleeper that flips over a lot in the night. Was a touch chilly at about 30° but also wasn't zipped fully. I camp around 50 times a year and am excited to see how it holds up!