Made in the U.S.A. exclusively for Bozeman Mountain Works for distribution at Backpacking Light by Nunatak Gear

Description

Click here to download the Quantum Arc X User Notes (Adobe PDF)

We've spent years scratching our heads, testing down sleeping bags for ultralight backpacking. We've tested suites of "almosts-but-not-quites" from Western Mountaineering, Marmot, Ph.D., and other "top-tier" manufacturers of down bags, with no success.

Finally, two years ago, we launched into an extensive period of testing of a product that we thought might be the ideal bag design for the lightweight mountain backpacker. You can read one of our reviews here.

Bozeman Mountain Works has contracted Nunatak USA in a collaborative effort to bring you the warmest 16 ounce sleeping bag on the market. Based on the Arc Alpinist design, our "X" version has turned out to be one of the most innovative and ideal products for ultralight backpacking we've ever found. We have worked with Tom Halpin to modify their standard design to bring you a bag that truly does weigh one pound, has generous loft, and is appropriate for three season use in the high mountains of the Continental United States.

The Arc Alpinist X variable girth down sleeping bag is produced exclusively for us. We are manufacturing small production lots that are selling out very fast. If you would like to pre-purchase one of these bags, we require payment in full up front and we will guarantee that you receive a bag from the next production lot (check this page for availability updates and production schedules).

Specifications

Weight

Are you tired of manufacturers that refuse to accurately report their fill weights? Yeah, us too. We promise to provide you with accurate information about exactly where the weight is spent in our sleeping bags. Here's a breakdown of the weight distribution in a Quantum Arc X, size Regular:

• Weight: 16.75 oz +/- 0.14 oz (mean and standard deviation calculated on a sample size of n=11 bags) (size Regular) and 19.07 oz +/- 0.22 oz (n=9) (size Long) - note that the bags are shipped with a LOT of extra strap webbing (grosgrain), and 0.5 to 0.7 ounces can be easily trimmed for most users.
• Shell Weight: 6.90 oz (average, total range is < +/- 0.05 oz)
• Fill Weight: 8.82 oz (average, range is < +/- 0.35 oz)
• Notions Weight: 1.04 oz (average, range is < +/- 0.05 oz); notions include two flat buckles used in the "under" straps, several feet of grosgrain webbing, a mating snap at the collar, and an elastic drawcord and toggle at the collar.

Other Specifications

• Fabric: 0.85-0.90 oz/sq.yd. Pertex Quantum (downproof ripstop nylon with DWR), used for both lining and shell (color varies with production lot; early '05 bags are being made with a light blue outer shell)
• Baffle Fabric: Top-grade noseeum mesh netting
• Baffle Height: 2"
• Baffle Spacing: 5.0"
• Down Fill Grade: 800+
• Lengths: Regular (sized for persons up to 5'10" in height) and Long (for up to 6'6")
• Packed Size: 4" x 12"
• Interior Girth Dimensions: 55" Shoulders / 45" Hips / 38" Footbox (NOTE: shoulder and girth dimensions are variable depending on the extent to which you secure the bag around you on the ground surface)

Special Offer for Premium Membership Subscribers

BackpackingLIGHT.com Premium Members receive special pricing and inventory rights on this product - please inquire with our Contact Form if you are a member and want to purchase this item.

Prototype Specifications

Our final prototype is complete (pictured above). This prototype weighs 15.5 oz (size regular) and we do intend to add another 1/2 oz of down for the shipping verision. Even so, the bag is 4+ inches thick (double layer) at the shoulders and tapers to 7" of loft in the footbox. The continuous baffles allow you to distribute down to the top to give you an effective single layer loft of 2.5 inches. This bag's loft exceeds that of the Rab Quantum Elite Top Bag, Western Mountaineering Highlite, and the Feathered Friends Vireo.