Western Mountaineering NanoLite Quilt Review

Last summer, Western Mountaineering finally introduced two quilts into their vast line of sleeping bags, both made in the USA using some of highest quality materials available. We were one of the first to get our hands on the 11oz. NanoLite quilt for some summer and fall bikepacking. Here’s a first look, thoughts on this impressively lightweight quilt, and a comparison of other lightweight quilts on the market…

Western Mountaineering has always set a high standard when it comes to quality gear. Although there are a few other respected brands out there making great sleeping bags and quilts, I’ve always been excited to see the Western Mountaineering bags in Canadian gear retailers like Mountain Equipment Co-op, bringing a readily available premium option to the average Joe.

I’ve used several different models now, from the 10°F (-12°C) rated VersaLite to their 32°F (0°C) SummerLite, and have always had a positive experience. All of their bags are made in San Jose, California, and are often signed by the person who made them. Plus, due to their unique staffing model, you can be certain the people who made your sleeping bag or quilt are the best at what they do. For example, the person sewing the baffles and footbox on the NanoLite Quilt does only that, and won’t suddenly be in charge of dealing with zippers or yokes. The end result is a high-quality sleeping bag made from some of the best materials out there, and one that’s available from retailers worldwide.

Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review

The NanoLite and AstraLite Quilts were released in response to feedback from customers and dealers over the last few years. As per Western Mountaineering’s usual approach, the bags are made from a proprietary 7-denier shell fabric and 10-denier liner. Pair these extremely lightweight fabrics with their 850+ fill power down, and you’ve got one of the lightest summer quilts available.

Flat elastic loops on the bottom of the quilts attach to any type of sleeping pad, and an additional elastic lace adjusts to the pad’s width to help eliminate drafts. Both use small cord locks to help accommodate different pads (though I left things fairly loose to provide more room to move around inside the quilt). There’s also a single button snap on the back to help keep things tight around the draft yoke. A sewn through foot box and insulated yoke with elastic closure also help to keep the warmth in where it belongs. The AstraLite is rated for 26°F (-3°C) and the NanoLite is rated for 38°F (3°C). Both quilts are offered in a 5’8” model for those 6’ and shorter, and a 6’4” model for those taller than 6’. I tested a 5’8” NanoLite.

  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review

I’m a firm believer in investing in high-quality camping gear for bikepacking where possible. Bikepacking on singletrack-heavy routes is much more enjoyable when the bike you’re riding handles like a mountain bike. Let the rear end skid around corners, catch a bit of air, and get a little playful with things. Considering the weight of a steel hardtail with front suspension, big tires, and a dropper post, I think it’s worth spending a bit of money on lightweight gear, specifically my sleep system.

I was able to snag the ultralight MSR Carbon Reflex 1 tent, which I reviewed here, plus Klymit’s new V Ultralite SL sleeping pad, and after hearing about Western Mountaineering’s grand entrance into the world of quilts, I knew I had to get my hands on one to complete my sleep system. Beside the potential weight savings, what also drew me to a quilt was the increased internal space and the ability to toss and turn without hassle, something that often annoys me with lightweight, tapered sleeping bags.

The NanoLite, being the lighter of the two quilts, offers a down fill weight of 6.5 oz (5’8” model) and 7.25 oz (6’4″ model), with a total weight of 11 oz or 12.5 oz, depending on the size. The internal shoulder width of 68” and hip area of 38” offer just enough room inside without feeling snug anywhere along my body. Plus, the handy adjustable elastic loops on the bottom mean that the overall size of the quilt can be fine tuned to match the outside temperature or desired feel. Compared to the Sea To Summit Spark SP I, an ultralight sleeping bag that I reviewed last summer, the NanoLite offers much more space around my shoulders, even though I possibly should have opted for the longer version to give my feet a little more room. For anyone teetering around 6’, I’d recommend the longer 6’4” version. It won’t just be more comfortable, it’ll also increase the usable temperature range by offering more loft in key parts of the quilt.

Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review

While bikepacking on the Oregon Timber Trail last summer, I didn’t encounter many nights colder than 45°F (7°C), so the NanoLite was more than enough to keep me comfortable. Most nights I would just lie on top until things cooled down a bit, eventually retreating inside the comfort of the quilt. Any time the temperature fell below 23°F (-5°C), like during a night scouting the Vapor Trail in Colorado this fall, I was happy to have some merino long johns, thick socks, a toque, and an insulated jacket to put on. Those kind of conditions are already pushing the absolute lower limit of the bag, but with some foresight, I’m sure I could sleep comfortably in even colder temperatures.

I liked not having any zippers to fiddle with, and although quilts require a bit of setup before getting into bed, it’s easy enough to slip the elastic straps over your sleeping pad when setting things up for the night. In my opinion, having an insulated yoke and footbox makes a huge difference when it comes to comfort and warmth, and these features also set the Western Mountaineering NanoLite apart from other lightweight quilts currently available. It’s the lightest and most packable sleep system I’ve ever owned, packing down to the size of a small melon, making it ideal for ultralight bikepacking trips or endurance-style events.

  • Western Mountaineering NanoLite Quilt Review
  • Western Mountaineering NanoLite Quilt Review
Western Mountaineering NanoLite Quilt Review

If I had to get really picky, I guess getting in and out of the NanoLite quilt can be slightly awkward. Since there are no zippers or quick releases for the elastic straps like on the Katabatic Gear and Enlightened Equipment quilts, you’re pretty much forced to slide out backwards. Depending on what kind of shelter you’re using, and if there are doors, this could make for difficult exit when nature calls. With this in mind, the Western Mountaineering quilts may be best suited for tents with rear entries, tarp setups, or for cowboy camping.

One other thing I noticed was the lower than average fill weight of the NanoLite, at 6.50oz. It seems that other comparable cottage-brand bags offer a bit more fill weight, closer to 8 – 9.5 oz, for regular length ~40°F rated quilts. The total weight of the quilt and temperature rating should be indicators that the NanoLite is not as versatile as other options out there. For those expecting slightly cooler temperatures, check out the AstraLite.

Ultralight Quilts Compared (35-40°F)

Here’s a quick comparison of seven bikepacking-friendly quilts that all fall within a similar temperature range of 35°F to 40°F (1.6°C – 4.4°C). It should be noted that this is normally considered a ‘fast and light’ range, and quilts rated for 30°F provide more versatility. Thankfully, many of the options listed below are also offered in warmer versions. Plus, a few manufacturers provide many customizable features, including length, width, and the fill power of the down used. For the sake of consistency, I’ve gathered the specs below based on the most standard options available for users up to 6’ tall. Prices will vary depending on which specifications are chosen.

Product Total Weight g/oz Fill Weight g/oz Temp Rating °F/°C Price
Western Mountaineering NanoLite 311/11 184/6.5 38°/3.3° $330
Enlightened Equipment Enigma 370/13 221/7.8 40°/4.4° $265
Enlightened Equipment Revelation 400/14.1 232/8.2 40°/4.4° $255
Katabatic Chisos 414/14.6 201/7.1 40°/4.4° $355
Zpacks Solo Quilt 420/14.8 258/9.1 35°/1.6° $339
Therm-a-rest Vesper 425/15 255/9 32°/0° $319
Nunatak Equipment Arc UL 439/15.5 260/9.9 40°/4.4° $340
Katabatic Gear Flex 479/16.9 260/9.2 40°/4.4° $324
Feathered Friends Flicker 40 578/20.4 238/8.4 40°/4.4° $309
Western Mountaineering NanoLite Quilt Review


  • One of the lightest quilts available at 11 – 12.5 oz.
  • Insulated yoke and footbox keep things comfortable and warm.
  • 38°F temperature rating is fairly versatile, making it ideal for spring, summer, and fall trips.
  • Made in USA, using the highest quality fabrics and responsible down sourcing.


  • No zippers or quick-release straps means there is only one way in and out of the quilt.
  • NanoLite only has 6.5oz of fill, compared to 8 – 9.5oz in similar quilts.
  • You will need another bag or quilt for cold weather trips.
  • Model Tested Western Mountaineering NanoLite Quilt (5’8″)
  • Weight 311 grams (11 oz)
  • Price $330
  • Manufacturer’s Details WesternMountaineering.com


When it comes to overall quality, Western Mountaineering is hard to beat. Unbeknownst to most, they’re a small company that takes the materials used, workmanship, and the weight-to-warmth ratio of their products very seriously. A lot of Western Mountaineering fans will be stoked to finally see an ultralight quilt from the company, and as expected, the NanoLite is possibly one of the lightest quilts currently available. When compared to other ultralight down quilts, the fill weight is on the lower end of the spectrum, which is likely why this off-the-shelf quilt is so damn light. The NanoLite is guaranteed to significantly reduce your sleep system’s total size and weight, and it’ll do so without sacrificing any comfort on milder nights under the stars.

Next time, I would grab the longer 6’4″ bag to free up some space around my feet, and if I hadn’t spent my summer riding in mostly warmer climates, the AstraLite Quilt would offer a little more versatility. Either way, I fully expect to continue using and enjoying the NanoLite Quilt this spring and summer as well.


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