MontBell UL Spiral Down Hugger Sleeping Bag Review

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Like MontBell's existing Super Stretch System, their new Super Spiral Stretch System is unique. Basically MontBell found an alternative way to create a stretchy sleeping bag, and save some weight to boot. The technology is best described in their own words: "New for 2009, MontBell has incorporated a classic tailor's technique to address sleeping bag comfort issues. 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.

The new Spiral Down Hugger line also introduces 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. Apparently MontBell is very satisfied with the new technologies because they intend to extend the Super Spiral Stretch System across their entire sleeping bag line (available March 2010), replacing the current Super Stretch technology.

ARTICLE OUTLINE

Introduction
Description
Performance
Comparisons
Assessment
Specifications

# WORDS: 1760
# PHOTOS: 5

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Viewing 8 posts - 26 through 33 (of 33 total)

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Posts
Jul 12, 2010 at 10:59 am #1628228

Marc Clarke
BPL Member

@marcclarke
Locale: Front Range of the Rocky Mountains

For what it is worth, I think the Montbell-supplied stuff sack is WAY TOO SMALL (as does the original reviewer). I carry my #3 Long in a 20 liter dry bag loosely fit into the bottom of my pack rather than in the tiny factory-supplied stuff sack.

Similarly, the Montbell factory-supplied cotton storage bag that came with my U.L. Spiral #3 Long is also WAY TOO SMALL, as I literally have to stuff the sleeping bag into the cotton storage bag. I'm out shopping for a MUCH larger non-Montbell cotton storage bag.

Jul 12, 2010 at 10:39 pm #1628471

John RB
BPL Member

@biggyshorty

marc,
great breakdown. thanks again. for what its worth to you, rei has great large "natural cotton" non-stuff storage sacks for sleeping bags. i've gotten 2 in past sales for $1 each…

Jul 12, 2010 at 11:19 pm #1628484

Marc Clarke
BPL Member

@marcclarke
Locale: Front Range of the Rocky Mountains

I picked up an aftermarket "natural cotton" non-stuff storage bag today. Thanks for your tip. :-)

Jul 15, 2010 at 4:09 pm #1629397

M Stein
Member

@a-k-a
Locale: Northern California

Hello, all,

I myself recently asked MontBell customer service to provide EN ratings, and in my case, they wouldn't give it out.

But by poking around the sites linked to on Western Mountaineering's "international dealers" page, I was able to turn up the super-secret EN Rating for the WM Summerlite.

The Summerlite is +6 C/+2 C/-14 C, or for us retrogrades who use the Neandertal scale…

WM Summerlite
COMFORT: 43 F
LOWER LIMIT: 36 F
EXTREME: 7 F

Treating James' experience as a baseline (where the WM bag proved warmer than the MB), we might consider the MontBell bag to be a 40 F bag, rather than a 30 F.

For what it's worth….

Nov 30, 2010 at 1:17 pm #1669411

Ultralite Hiker
Spectator

@ultralite

"The Summerlite is +6 C/+2 C/-14 C, or for us retrogrades who use the Neandertal scale…

WM Summerlite
COMFORT: 43 F
LOWER LIMIT: 36 F
EXTREME: 7 F
"

Thanks for this info. However, based on everything I have read here on the Summerlite (which is quite a few threads) most people say the summerlite has a pretty conservative rating. Why would WM put out a 32 degree bag that has a lower limit of 36? Or are you saying these tests were done independently of WM?

Either way, most here agree the Summerlite is true to rating, or maybe even conservative. I agree that the UL Super Spiral wouldnt be quite as warm, but 40 seems too high for the bag.

Nov 30, 2010 at 1:23 pm #1669412

David Ure
Member

@familyguy

"Why would WM put out a 32 degree bag that has a lower limit of 36? Or are you saying these tests were done independently of WM?"

Yes – EN testing is done by an Independent body. For all intents and purposes, this WM is a 36 degree bag.

Nov 30, 2010 at 2:31 pm #1669431

Ultralite Hiker
Spectator

@ultralite

I stand corrected then. So 40 degrees for the UL Super Spiral, I was about to puchase but that makes me hesitate.

I find the Summerlite too confining.

Jun 1, 2011 at 5:08 pm #1743726

Jerry Getz
BPL Member

@jerzyshore
Locale: Southeastern, PA

I am a very fidgety side sleeper, and the room afforded by this bag is truly second to none. In my opinion the best thing is the way the bag sort of sucks itself down close regardless of position, minimizing open airspace between the bag and your body. For me, that is what makes all the difference.

JSG
Author

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