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Sierra Designs Cloud 800 / 35 Review

A feature-rich and innovative sleeping bag that blurs the line between bag and quilt
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Price:  $350 List | $299.95 at Amazon
Compare prices at 2 resellers
Pros:  Roomy hood fits a camping pillow, sleeping pad slot, zipperless system, comforter design, convenient foot vent
Cons:  Not the best for side sleepers, warmth-to-weight ratio could be better
Manufacturer:   Sierra Designs
By Justin Simoni ⋅ Review Editor  ⋅  May 11, 2020
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66
OVERALL
SCORE


RANKED
#7 of 13
  • Warmth - 30% 5
  • Weight - 25% 6
  • Comfort - 20% 7
  • Versatility - 15% 9
  • Features - 10% 8

Our Verdict

Innovation is obvious in the Sierra Designs Cloud 800 / 35. This is especially appreciated for people who are looking for the most attractive features of a sleeping bag, coupled with the philosophies of a quilt. The Cloud 800 pairs a generous sleeping hood, deep footbox, and the cut of a mummy bag with a quilt-like zipperless design that's easy to get in and out of, as well as adjust and vent. The bag's approach to comfort and versatility works best for back sleepers. If you're a side or active sleeper, perhaps look at other products. All the design features take a lot of material to stitch up, which makes this bag's warmth to weight ratio lower than most other bags in our review. The zipperless comforter design affords a ton of room for those with wide shoulders, which separates this bag from models we've tested with a slimmer design in the chest to reduce weight.

Compare to Similar Products

Our Analysis and Test Results

This bag stays true to its advertised rating of 35F and may be comfortable to sleep in if temps dipped lower, but you'll want a high R-value pad underneath it. A sleeping pad for this bag is absolutely required, as the bag has a 12" x 24" panel where your back will rest on that has no fill in it at all. Much like a quilt, this allows the down that's in the bag to cover the top of you with insulation rather than having this down be compressed underneath you, which wouldn't provide much heat retention.

Performance Comparison


The Sierra Designs Cloud 800 35's zipperless design and oversized comforter can help one find solace after a long day of hiking.
The Sierra Designs Cloud 800 35's zipperless design and oversized comforter can help one find solace after a long day of hiking.

Warmth


On summer backpacking trips along the Colorado section of the Continental Divide Trail, where nighttime temps can vary with the elevation of camp, as well as how entrenched in an inversion layer of a deep valley you are, the Cloud 800 / 35 showed it's flexibility for making a comfortable night. The Cloud 800 has a higher temp rating (35F) than some of the other bags we've tested, with a warmth to weight ratio that tells us that there's more shell material than most bags when compared to the amount of down fill.

This is somewhat to be expected from a bag rated as it is, but the Cloud 800 uses the fill it does pack very strategically with its generously long footbox that extends to your hips, as well as it's integrated comforter - massive for an ultralight bag. This comforter is also fairly roomy across the shoulders, which should appeal to those that want an ultralight sleeping bag but find the cut of some of the other bags we've reviewed too trim for comfort. The generous hood will also certainly keep your head warm, without the need for an additional down-filled cap you may want to utilize when using a quilt that lacks any sort of warmth or protection for your head.

The Sierra Designs Cloud 800 35 features a zipperless footbox vent  and zipperless comforter design making it very easy to lounge around camp while wearing the bag itself as an insulation layer.
The Sierra Designs Cloud 800 35 features a zipperless footbox vent, and zipperless comforter design making it very easy to lounge around camp while wearing the bag itself as an insulation layer.

For warmer, clear nights, The Cloud 800's zipperless foot vent becomes useful if you need to stick out your feet for a little ventilation, or even if you need to walk around camp in the middle of the night without losing the heat you've captured in your bag while sleeping. For colder nights, you'll most likely want to layer up with some additional clothes, and cinch the hood up tightly. The integrated comforter is so wide that you'll want to wrap the left-hand side of it across your left shoulder, and tuck it under your back to keep things snug on the coldest of nights.

There's perhaps a bit of a learning curve on how to utilize all these features perfectly to get the most out of the bag, which differentiates this bag from the more "keep-it-simple" sleeping bags and quilts we've tested.

The Sierra Designs Cloud 800 included stuff sack packs down the bag to  7" x 13".
The Sierra Designs Cloud 800 included stuff sack packs down the bag to 7" x 13".

Weight


All those clever features of the Cloud 800 that bestow upon it so much flexibility and comfort do come at a cost, and that cost is the overall weight. Many of the features including the generous integrated comforter, zipperless foot vent, large hood, and pad sleeve just take some extra yardage of shell fabric to sew. A simpler, ultralight bag can be purchased that's lighter, with more fill, and rated warmer than the Cloud 800. So if warmth to weight is the metric you're concerned with over anything else, pay attention to those other bag options.

The unique designs of the Sierra Designs Cloud 800 do take a fair bit more material and stitching when compared to other bags we've tested.
The unique designs of the Sierra Designs Cloud 800 do take a fair bit more material and stitching when compared to other bags we've tested.

The weight of the down fill in the Cloud 800 is 10.4 oz, which is a tad less than the overall weight of the entire bag which weighs in at 23 oz. This is one of the few bags we've reviewed that has less down fill weight than compared to all other materials. The shell material itself is a 15D nylon ripstop, which is on par or actually slightly surpasses other ultralight bags/quilts that we've reviewed, making the bag feel in the same class as these other offerings.

The Sierra Designs Cloud 800 35's generous comforter and zipperless design allows for a roomy fit around the shoulders.
The Sierra Designs Cloud 800 35's generous comforter and zipperless design allows for a roomy fit around the shoulders.

Comfort


The Cloud 800's biggest strength may be in its comfort. After all, its most unique feature that makes it stand out from all the other products we've tested is its oversized comforter. While many of the bags reviewed cut weight by keeping the fit trim, the Cloud 800 has a more than generous fit in the shoulders due to the fact that the zipperless design allows you to open up the bag as much as you would reasonably like. This could be especially appreciated to those who feel claustrophobic in other ultralight mummy sleeping bags.

Shoulder girth is advertised by the manufacturer at 62", which is far roomier than most any other sleeping bag we've tested. The hip girth tells a similar story, claimed at 60", ranking this bag one of the most generous bags in this measurement. The footbox girth measures at 42; extremely spacious for an ultralight bag. All of this makes for a bag that's atypically cozy for an ultralight sleeping bag, while also making things easier to get into and out of.

The Sierra Designs Cloud 800 35 unique zipperless design makes it easy to get into and out of the sleeping bag
The Sierra Designs Cloud 800 35 unique zipperless design makes it easy to get into and out of the sleeping bag

The zipperless design of the Cloud 800 also means that there's no wrestling with stuck zippers in the middle of the night. Instinctually, you may find yourself clutching the bag's comforter tighter on colder nights, and looser on warmer. Sticking your feet out of the footbox's vent is intuitive enough as well. The zipperless design paired with the oversized comforter may not appeal to dedicated side sleepers or super active sleepers, as the comforter may wander away from your body if you fidget through the night and this could let in drafts. But for back sleepers and less energetic sleepers, the comfort of this bag is hard to beat at this temperature rating.

The Sierra Designs Cloud 800 35's comforter could come off from under your shoulder if you roll around in the bag - something side and active sleepers should note.
The Sierra Designs Cloud 800 35's comforter could come off from under your shoulder if you roll around in the bag - something side and active sleepers should note.

One thing we may have to note is the sewn-through design of the Cloud 800. Most bags and quilts we've tested use some sort of continuous baffle design. Continuous baffles theoretically keep more of the down fill between you and the outside, while a sewn-through design adds more opportunities for your body to be pressed next to the thin shell fabric at the sewn seams. The shell material doesn't add much insulation from nighttime temperatures. Most bags and quilts we've tested opt for the continuous baffle design as a way to tweak the warmth of the bag, as the continuous baffles allow you to shake the down through different parts of the bag.

With the Cloud 800, this wouldn't be a step you'll be required to do, as the comforter provides a full range of tightness/looseness you can sleep within, which in turn helps regular temperature. Along with the comforter design, there is no insulation at the upper half of the bottom bag (shoulders to lower back), so no insulation will ever need to be sloshed back into place. A sewn-through design is marginally lighter and in practice should work just fine for a bag at this temperature rating.

Versatility


Similar to any full zip mummy bag, the Cloud 800 can be very versatile, with just a little imagination. The zipperless design and footbox vent make it really easy to regulate temps - especially when things get warmer than you had planned. For unanticipated colder nights, you may opt to bundle up with an additional base layer, as the roomy comforter may make it a little harder to really keep things really sealed tight.

Burrowing deep inside the bag wouldn't be a problem, as the generous girth of all three major measurements of the bag (shoulder, hips, and footbox) give the bag a roomy feel. Just make sure to wrap the comforter around yourself as you would at home in your bed. Cinch the large hood tight to really keep things toasty. Ultimately though, the Cloud 800 stays true to its 35-degree rating, so don't expect to magically be warmer than your backpacker buddies who may have brought along 30 or even 20-degree bags.

The Sierra Designs Cloud 800 35 features a zipperless footbox vent  and zipperless comforter design making it very easy to lounge around camp while wearing the bag itself as an insulation layer.
The Sierra Designs Cloud 800 35 features a zipperless footbox vent, and zipperless comforter design making it very easy to lounge around camp while wearing the bag itself as an insulation layer.

For lounging around in the early morning while wearing your sleeping bag as the ultimate cold layer, the Cloud 800 may be impossible to beat. The zipperless design naturally unfurls just below your chest for optimal mobility when grabbing that fireside cup of joe or adding dried fruit to the morning's oatmeal. The footbox vent allows your feet to stick out and can be hiked up slightly to walk short distances to grab that one item you forgot inside your tent.

Features


The Cloud 800, more than any other sleeping bag we've tested, has truly attempted to depart from standard ultralight sleeping bag design ideas. Some of our favorite features are the roomy fit from head to toe, footbox vent, pad sleeve, as well as the comforter coupled with the zipperless design. This bag is going to have both its fans and its detractors, as the design ideas it introduces have a great deal of polarizing potential.

The Sierra Designs Cloud 800 35 features a generous pad sleeve to insert a sleeping pad in. To save weight  no down fill is located at the bottom of the bag where the pad sleeve fits.
The Sierra Designs Cloud 800 35 features a generous pad sleeve to insert a sleeping pad in. To save weight, no down fill is located at the bottom of the bag where the pad sleeve fits.

Taken as a whole, all the features work well together, and we're pretty certain that if you find yourself comfortable in the bag the first time you try it out in-store, you'll love it while on the trail. If you're first and foremost a strict adherent of "Keep it Simple", then the Cloud 800's list of well thought out details may just be a detraction.

Value


For how many features it packs into such a lightweight bag, the Cloud 800 / 35 is priced very competitively when compared to other sleeping bags and quilts we've tested in this category. The temperature rating is a higher than some of the other products we've tested, at 35F. Generally, the cheaper the price, the less down fill you may find in the bag and that holds true for the Cloud 800, which has one of the lowest warmth to weight ratio of all the products we've tested. Still, the Cloud 800 is more comfortable and versatile than most any other sleeping bag we've tested. It's hard to really think of the Cloud 800 as merely a sleeping bag. All the materials are of high quality. When taken care of correctly, this bag should hold up to many years of use.

Our product testers seem quite in happy in their ultralight sleeping bags  including then Sierra Designs Cloud.
Our product testers seem quite in happy in their ultralight sleeping bags, including then Sierra Designs Cloud.

Conclusion


The Sierra Designs Cloud 800 / 35 is a solid sleeping bag choice for warmer summer nights. It excels in comfort, versatility, and features - so long as those features are compatible with your sleeping style. If you feel limited on what your traditionally designed mummy sleeping bag has to offer, but don't want to jump ship to a full-on quilt system, the Cloud 800 may just be the best of both worlds.

Justin Simoni