by Ryan Jordan | 2006-05-08 03:00:00-06
The Feathered Friends Vireo is a hoodless, zipperless, mummy-style sleeping bag with a fully insulated girth, Pertex Quantum shell and lining, and 800+ fill down insulation.
At 17 ounces, it certainly qualifies as ultralight, and with a manufacturer temperature rating of 45 °F, it's worth a look as a two-season backcountry bag.
In addition to its spartan feature set (no hood or zipper), its most unique feature is how the insulation is distributed.
With an even distribution of down through continuous baffles through the circumference of the bag, the Vireo features no cold spots when rolling.
However, with less loft (and more girth) in the chest area than in the trunk and legs, the Vireo is ideally paired with an insulating jacket for best insulating efficiency. The Vireo is the first mummy-style bag that is specifically designed to integrate with existing insulating clothing in a meaningful way that saves weight and improves overall system performance. A wider chest area girth means that neither the clothing nor the bag's insulation will become compressed when layered.
I used the Vireo through Montana in the Fall of 2005 and even into the winter season. On its own and in a bivy sack, I found it to be comfortable at the manufacturer's temperature rating. With a hooded down parka (Rab Neutrino, 21 oz), I was comfortable down to 32 degrees, although my legs did start to get a little chilly. Used as an inner bag, with a 16 oz down quilt as a top bag over the Vireo, I had a winter system that was comfortably warm down to 5 degrees with the down parka.
My favorite use of the Vireo was as a climber's "half bag". I used the Vireo in combination with a synthetic parka (Patagonia DAS) and an Integral designs eVENT South Col bivy sack during a fall ridge traverse. Because the belay jacket was too large to prevent loft compression in the Vireo, I wore the jacket outside the bag, with the bag cinched up just below my armpits. Unlike a typical mountaineer's elephant's foot half-bag, the Vireo provides a far better bag-to-jacket seal and was surprisingly warm in this configuration during a 35-degree, windy bivy on Montana's Spanish Peak crest in October.
The primary limitation of the Vireo is its fixed girth: it may be too tight (especially in the footbox) for bigger folks, and in the chest area, too big for smaller folks. But if it fits you "just right", it's one of the best performance:weight buys in down sleeping bags today.
Other Features: Non-stretch one-handed drawcord opening; continuous baffles.
"Feathered Friends Vireo Sleeping Bag SPOTLITE REVIEW," by Ryan Jordan. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/feathered_friends_vireo_sleeping_bag_spotlite_review.html, 2006-05-08 03:00:00-06.