Bibler Winter Bivy Long-Term Report
- Here it goes. Edit away.
Happy New Year - Stu B
Bibler Winter Bivy
Year 2002 Model
Stuart Bilby, male, stu@..., Age 36, 5'9" (176 cm), 176 lb (80
Since my Field Report I have used the Bibler Winter Bivy twice in New
Zealand in the snow; once with and once without a tarp. I have also
used it for twenty-seven nights in Nepal, mostly under a tarp, but
also with no additional shelter, under overhanging rocks and in cold
Minimum overnight temperatures varied from 1°F to 68°F (-17°C to 20°
C). In Nepal the Bivy was useful for:
Keeping the sleeping bag dry in rain, snow, spindrift, dew and frost,
Backup for times when separated from the person carrying the tarp,
Keeping the sleeping bag clean, no need for a ground sheet
In contrast to my earlier testing (see Field Report), on both recent
nights in New Zealand, condensation or ice formed on the inside of
the Bivy. This also occurred in Nepal on about seven of the nights.
Condensation occurs when air touches a surface colder than its
dewpoint for a given humidity. Often the surface of the Bivy either
inside or outside was cold enough for condensation to occur. This is
not a criticism of the Bivy because some condensation is inevitable
in such conditions.
Overall however the condensation seemed to be less than that
occurring in my companion's old Gore-Tex bivy and I had the
impression that the Winter Bivy is highly breathable.
Size and Shape
On several nights in Nepal I was cold, despite wearing all my clothes
except my gaiters. On investigating, I discovered that when I zipped
the Bivy up, it crushed the down at the foot of my sleeping bag. I
was using a Macpac Neve sleeping bag, which only has down on the top,
and a full-length Thermarest UltraLite inflatable mattress. This
squashing of the down surprised me because in my earlier tests I had
not observed a problem.
It was less noticeable when using a synthetic sleeping bag,
presumably because the synthetic fill resists crushing. Zipping the
opening created tension along the top of the Bivy pulling it tight at
the feet and preventing the down at the feet from lofting fully. This
was exacerbated on any slope because slipping downhill pulled the
Bivy tighter. Leaving the zip undone and my head out mostly solved
Any person taller than me, 5'9" (176 cm) should check that the Bivy
is large enough for them.
When using a Bivy sack on cold or rainy nights I like to leave a
small opening over my mouth to breathe out of so as to reduce
condensation. Once I had tied small strings on the zip tags this was
easy to achieve. The zips have tags at both sides allowing the mouth
opening to be adjusted from side to side depending on whether I am
lying on my side or back.
The opening to the Bivy naturally sits at a level between my neck and
chest. I would much rather have it at the height of my mouth but
pulling it up squashes the sleeping bag's down around my toes.
I have paid little attention to protecting the fabric from damage. I
have slept on rocks and gravel on about ten nights with the Bivy
against the rocks and a Thermarest on the inside. The fabric has
lasted well with no damage and only a little scuffing of the satin
finish on the underside.
The seams are undamaged despite a few desperate struggles in the
night to get out quickly.
The fabric and the seams have not shown any signs of leaking in my
use although I have only once used the Bivy with heavy rainfall
directly on the whole bag.
In dry conditions the fabric develops a static charge that attracts
grass, chaff and dust. This became mildly irritating when packing the
Bivy on the high pastures in Nepal.
The Bibler Winter Bivy is amazingly light, tough enough, highly
breathable, and keeps rain out. I would prefer it to be a little
larger with the opening nearer the top. Overall it is one of my
favourite pieces of equipment and goes in my pack for nearly every
I live in Auckland, New Zealand and have been heading into the
mountains for 16 years. I am an experienced backpacker, tramper and
climber and most of my trips are multi-day off-trail trips. I have
done three trips trekking in the Himalayas. I love long trips up the
remote gorges, forests and glaciers of the South Island's west coast.
Over the last two years I have converted to a lightweight style.
Thank-you to Bibler and BackpackGearTest for the chance to test the
Bibler Winter Bivy.
6 January 2003
- Looks good, Stu. Thanks.
P.S. I feel like I'm in an English class or something, reading Mr.
Bilby's report on the Bibler Bivy. :) And my spell checker says Stu is
John F. Meyer, Jr. jfm@... www.johnmeyer.net
NASO, PSOA, GCFOA USARA, CFAR, NORBA, USAT, FTA
(and BGT Bibler Winter Bivy monitor)
#Bibler Winter Bivy
#Year 2002 Model
#Stuart Bilby, male, stu@..., Age 36, 5'9" (176 cm), 176 lb (80
- Nice series of reviews, Stu--I'm sold! I was sold when they first
came up for testing, but now I'm even more sold, hehehee. I need one.