The MontBell UL Super Spiral Down Hugger #3 weighs 21 ounces (595 g) for size Regular and has more stretch than the UL Spiral Down Hugger #3.
Introduced in 2009, MontBell’s Spiral technology is an alternative way to create a stretchy sleeping bag and save some weight to boot. The Spiral technology is best described in their own words: “By integrating a woven fabric ‘cut on the bias’ and orienting the fabric’s warp and weft threads at 45 degrees to major seam lines, the sleeping bag becomes more fluid or elastic in nature. Additionally, ‘spring like’ crimped fibers are used in the weave of the fabric to capitalize on their inherent stretch properties.” Rather than the traditional horizontal or vertical orientation of the down tubes, they are oriented on a 45 degree angle and appear to spiral around the sleeping bag.
For 2010, MontBell has extended their Spiral Stretch technology to their entire line of sleeping bags. Thus the former “UL Super Stretch Down Hugger #3” is now the “UL Super Spiral Down Hugger #3.” That’s a mouthful, but it is descriptive. Whereas the previously reviewed MontBell UL Spiral Down Hugger #3 uses only the Spiral Stretch technology, the MontBell UL Super Spiral Down Hugger #3 (reviewed here) is a combination of the new Spiral Stretch technology plus the original Super Stretch technology (elastic stitching in the seams to create small "gathers" in the quilting), which allows the bag to contract and expand even more. So what are the differences between these two bags, and are these differences meaningful for backpacking?
The Spiral Down Hugger and Super Spiral Down Hugger share MontBell’s new 12 denier Ballistic Airlight sleeping bag fabric. Switching from 15 to 12 denier fabric plus spiral construction reduces the weight of a sleeping bag by about 2 ounces (57 g). In the Super Spiral series, that weight is added back due to the elastic stitching and slightly different bag lengths.
The common features of Spiral Down Hugger #3 and Super Spiral Down Hugger #3 are: 10 ounces (283 g) of 800 fill power down, 30 F (-1 C) temperature rating, spiral construction, 12 denier Ballistic Airlight nylon shell with Polkatex DWR, sculptured hood, and YKK #5 CN auto-locking zipper. The Super Spiral Down Hugger #3 no longer has a footbox drawcord to snug the bag around the feet, or shorten the bag.
The following table summarizes the differences between the two bags for size Regular.
|UL Spiral Down Hugger #3||UL Super Spiral Down Hugger #3|
|Weight||19 oz (539 g)||21 oz (595 g)|
|Zipper Length||59 in (150 cm)||67 in (170 cm)|
|Shoulder Girth Range||57-68 in (145-173 cm)||53-75 in (135-191 cm)|
|Bag Lengths||Regular fits to 5 feet 10 inches (178 cm), Long fits to 6 feet 4 inches (193 cm)||Regular fits to 6 feet (183 cm), Long fits to 6 feet 6 inches (198 cm)|
MontBell UL Super Spiral Down Hugger #3.
The purpose of MontBell’s stretch system is to gently draw the bag around the sleeper, which increases warmth by eliminating excess volume inside the bag. The left photo shows the bag’s shell relaxed, and the right photo shows the same area extended. The stretch system allows the bag to accommodate people of different sizes and shapes and provide freedom of movement.
I have always been impressed with MontBell’s Ballistic Airlight nylon shell fabrics and Polkatex DWR finish, but the new 12 denier shell on the Spiral Down Hugger is truly remarkable. It’s the softest sleeping bag fabric I have seen, and it sheds water like a duck’s back.
The Super Spiral Down Hugger’s hood (left) covers the face very well and draws easily via a simple braided cord and cordlock. On the inside, the bag has a thinly insulated flap that covers the zipper (right), rather than a puffy down-filled draft tube. The zipper has inside and outside pulls, and there is a Velcro tab at the top of the zipper to secure it.
I tested the Super Spiral Down Hugger #3 on seven backpacking trips, with nighttime temperatures ranging from 25 to 52 F (-4 to 11 C) in various shelters, like the Hyperlite Mountain Gear Echo 1 shown.
MontBell has revised bag sizing in the Super Spiral series to conform with most other manufacturers; size Regular now fits to 6 feet (183c m) and size Long fits to 6 feet 6 inches (198 cm). I tested a size Regular and found it perfect for my 6-foot/170-pound (183 cm/77 kg) frame. There is all the room you could ever want inside to wear extra clothing to extend the bag’s warmth.
The Super Spiral Down Hugger (and the Spiral Down Hugger) has a simple and lightweight zipper track (see photo above) that works. I experienced very few instances of zipper snagging in my testing. Rather than a puffy down filled draft tube along the zipper, MontBell uses a thinly insulated flap, much like the storm flap on a jacket. Although I did not feel any drafts or cold spots along the zipper, it quite likely does not insulate as well a down-filled draft tube.
I measured the bag’s average double-layer loft at 4.4 inches (11.2 cm), which gives a single-layer loft of 2.2 inches (5.6 cm). From our table of estimated temperature ratings based on measured loft (read our Backpacking Light Position Statement on Sleeping Bag Temperature Ratings), 2.2 inches (5.6 cm) of single-layer loft translates to about a 20 F (-7 C) rating, so the Spiral Down Hugger #3 appears to be conservatively rated (please take the time to read the referenced article and note that sleeping bag warmth depends on a number of factors).
The Spiral Down Hugger #3, is not the loftiest bag around with a 30-32 F (-1 to 0 C) temperature rating (see comparison table below). I found its warmth to be “average.” In my field testing, my methodology was to wear my basic sleepwear (dry wool socks plus microfleece top, bottom, and cap) inside the bag initially, then add insulated clothing later in the night if I got cold, noting the time and temperature when I got chilly. On nights when the temperature dropped down to freezing just before sunrise, I started getting chilly around 4:00 a.m. when the temperature was around 35 F (2 C). After donning my insulated clothing (or better yet putting it on the evening before), I was able to stay warm in the Spiral Down Hugger down to 25 F (-4 C).
I tested the bag’s water repellency by placing a puddle of water on the bag and checking for leakage after an hour. Not a drop soaked through, and after removing the water, there was no evidence of a puddle being there. This was verified in my field tests, where the bag did not absorb any water when I brushed against wet tent walls, and contacted a wet tent floor in another case.
The stuff sack provided is tapered and has two drawcords to stuff the bag down to bread loaf size. It’s simply too tight. In my opinion, the two drawcord design is overkill, extra weight, and overstuffing may damage the down over time. I prefer a stuff sack that does not overstuff a down bag, although it takes up a little more room in my pack.
The following table compares the MontBell UL Super Spiral Down Hugger #3 with some popular 30-32 F (-1 to 0 C) rated ultralight mummy style down sleeping bags. All of the bags have baffled construction, and the data are manufacturer specifications for a size Regular bag.
|Manufacturer||Model||Temperature Rating F ( C)||Single Layer Loft in (cm)||Weight of Down oz (g)||Fill Power||Total Weight oz (g)||Cost US$|
|MontBell||UL Super Spiral Down Hugger #3||30 (-1)||2.2 (5.6)||10 (283)||800||21 (595)||279|
|MontBell||UL Spiral Down Hugger #3||30 (-1)||1.9 (4.8)||10 (283)||800||19 (539)||249|
|Mountain Hardwear||Phantom 32||32 (0)||2.0 (5.1)||10 (283)||800||22 (624)||290|
|Western Mountaineering||SummerLite||32 (0)||2.0 (5.1)||10 (283)||850+||19 (539)||315|
|Marmot||Hydrogen||30 (-1)||2.5 (6.4)||10 (283)||850+||25 (709)||319|
|The North Face||Beeline||30 (-1)||2.4 (6.1)||10 (283)||850+||22 (624)||279|
|Sierra Designs||Nitro 30||30 (-1)||3.0 (7.6)||12 (340)||800||26 (737)||289|
By the numbers, the MontBell UL Super Spiral Down Hugger compares favorably with other bags in terms of down quality, fill weight, loft, weight, and cost.
I really like the Super Spiral Down Hugger’s soft lightweight shell fabric, fit/roominess, non-snagging zipper, hood, and low weight. It’s an excellent choice for an ultralight 30 F (-1 C) rated sleeping bag. It is not quite as warm as the Marmot Hydrogen and Sierra Designs Nitro 30, but it is not as heavy either. I have not personally tested the Western Mountaineering SummerLite, so I can’t comment on how well it compares in warmth.
The MontBell UL Super Spiral Down Hugger #3 stands out for its variable girth feature, superb shell fabric, nearly snagless zipper, easy to operate hood closure, and exceptionally light weight. This bag “hugs” your body as claimed, yet it easily expands as needed to accommodate different size people, varying amounts of clothing worn inside the bag, and different sleeping positions. Although the bag’s warmth is only average among its peers, that is not a particular problem for me since I typically wear my camp clothes (wool socks, insulated jacket and pants, fleece cap) in my sleeping bag anyway. The colder it gets, the more clothing I put on, so I typically have no problem staying warm down in a 30 F (-1 C) rated sleeping bag down into the mid 20s F (-7 to -1 C).
How does the Super Spiral compare with the Spiral Down Hugger? It provides a wider range of shoulder and hip stretch and has a longer zipper. The sizing for sizes Regular and Long are slightly different. Since I am a slender person, I would personally opt for the Spiral Down Hugger and save US$30 and 2 ounces (57 g). However, the Super Spiral Down Hugger would be a better choice for a larger person.
Specifications and Features
|Year/Model||2010 UL Super Spiral Down Hugger #3|
|Style||Hooded mummy bag with full-length zipper|
|What’s Included||Sleeping bag, stuff sack, cotton storage bag|
|Fill||800 fill-power down|
10 oz (283 g) size Regular
11 oz (312 g) size Long
|Construction||Multi-Tube Construction with Flow Gate technology, 5.5 in (14 cm) baffles|
|Measured Loft||4.4 in (11.2 cm) average double-layer loft|
Manufacturer Specification: “about 4 inches (10 cm)”
|Manufacturer Claimed Temperature Rating||30 F (-1 C)|
|Stuffed Size||5.5 x 11 in (14 x 28 cm)|
|Weight||Size Regular tested|
Measured Weight: 1 lb 5.1 oz (598 g)
Manufacturer Specification: 1 lb 5 oz (595 g)
|Sizes||Regular fits to 6 ft (183 cm)|
Long fits to 6 ft 6 in (198 cm)
|Fabrics||Shell and lining are 12d Ballistic Airlight nylon 0.86 oz/yd2 (29 g/m2) with Polkatex DWR. Fibers are solid core.|
|Features||Spiral stretch system, three-quarter-length two-way auto-locking zipper with inside and outside pulls, draft flap on inside of zipper, Velcro tab at top of zipper, sculptured hood, braided drawcord and cordlock closure on hood, tapered stuff sack with two drawcords, heat transfer logos|
Disclosure: The manufacturer provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the manufacturer under the terms of this agreement.