Field Report - Sierra Designs Osage Sleeping Bag - Andrew Priest
- Dear Group
Please find my Sierra Designs Osage Sleeping Bag Field Report below. The
HTML copy can be found at
My apologies for the lateness.
Sierra Designs Osage Sleeping Bag
July 26, 2005
Table of Contents
* Information about Andrew, the tester and author of this report
* Information about the Sierra Designs Osage Sleeping Bag
* My experience using the Sierra Designs Osage Sleeping Bag in the field
+ Testing location overview
+ Weather conditions
+ Field Experience
+ Concluding comments
Andrew Priest, Tester and Author of this Report
Perth, Western Australia, Australia
I am a 45 years old male, 180 cm (5' 11") in height, I weigh 106 kg (234
lbs). I have been hiking in Western Australia for approximately five
years. For the past four years I have been regularly walking leading on
and off-track pack carries with the Perth Bushwalkers Club. I am also into
geocaching. I consider myself as moving towards being a lightweight
tent-carrying bushwalker with my pack base weight in the 8 to 12 kg (18 to
26 lb) range. In 2003 I completed my End to End of the Bibbulmun Track. I
have also thru-hiked the Cape to Cape Track, the Coastal Plains Walk Track
(numerous times) and the Larapinta Trail (July 2005).
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Information about the Sierra Designs Osage Sleeping Bag
Description, year of manufacturer and MSRP: The Sierra Designs Osage
Sleeping Bag being tested is the men's regular size. It was received in May
2005. A tag attached to the bag indicates it was manufactured in 2004. The
manufacturer's suggested retail price at the time of writing is US$ 179.95.
The bag is part of the Sierra Designs Adventure Series range, having
Powerfill 600-Fill Goose Down insulation. The bag is a mummy design with a
distinct footbox, goose down insulation with a 40D polyester shell and
liner material and is rated at 2 C (35 F). The bag is described as having
the following features:
* Snag-Free zipper track (full length zipper on the left side);
* Chest pocket;
* Glow-in-the-Dark Zipper Pull;
* Pad locks to attach the bag to one's sleeping mat;
* Draft tube;
* Tucked stitching.
The bag was shipped with a stuff sack and a storage bag.
Weights and Measurements:
Measure Manufacturer's Stated Measurement My Measurement
Trail Weight 1.13 kg (2 lb 8 oz) 1.19 kg (2 lb 10 oz)*
Bag + Stuff Sack Not stated 1.25 kg (2 lb 12 oz)
Fill Weight 454 g (16 oz) Not verified
Inside length 2.02 m (79.5 ") Not verified
Stuff size 20 cm x 46 cm (8" x 18") 20 cm x 41 cm (8" x 16")
Shoulder girth 157 cm (62") Not verified
Hip girth 145 cm (57") Not verified
Footbox girth 109 cm (43") Not verified
* I have assumed trail weight to be the bag itself, i.e., without the
My experience using the Sierra Designs Osage Sleeping Bag in the field
Testing Location Overview: The hiking environment of the south-west of
Western Australia allows for hiking and backpacking from coastal plains to
forest. Elevation ranges from 0 to 585 metres (0 to 1,920 feet). Within
this region, I hike in varying conditions from forestry roads, to sandy
tracks to single-purpose walking trails, to rock hopping, to beach walking
to completely off-track walking through open and dense country.
Specifically the sleeping bag has been used during the field testing phase
on two walks in the south-west of Western Australia (four nights) and on
the Larapinta Trail in Central Australia (16 nights).
Weather Conditions: During the summer period, daytime temperatures average
30° C (86° F), whereas from March through to December the daytime average
temperatures range from 15° C to 26° C (59° F to 79° F). During the autumn,
winter, and spring periods the normal weather pattern is fairly wet with
frequent heavy rainstorms evident. It does not normally snow in Western
According to The Times Atlas of the World (Concise Edition - Revised 1997)
our weather is described as being "Mediterranean - rainy climates with mild
winters, coolest month above 0° C (32° F), but below 18° C (64° F); warmest
month above 10° C (50° F)." The atlas depicts the coastal area north of Los
Angeles as having the same climate.
The above describes the weather conditions common for the south-west of
Western Australia. For the Larapinta Trail hike, I took temperature
readings upon wake up in my tent on 12 mornings (lost my thermometer, so
missed the final four nights). Wake up time was generally 1/2 hour to one
hour before sunrise, but long before sun warmth. Nearly every campsite had
a ridge to the east blocking the sun for extra hour to two after sunrise.
My average temperature recording was 2 C (36 F).
Over the next six months I will be undertaking number of scheduled weekend
backpacks (one in May, June, August, September, and October) plus a 17
night walk of the Larapinta Trail in the Northern Territory. In addition,
subject to work commitments I am aiming to fit a few extra overnight camps
during the six month test period. The backpacks are normally of a duration
of one to two nights out. Camping is normally tent camping or in three
The Larapinta Trail walk will allow me to use the bag over seventeen
continuos nights in a tent in a area where the average mean minimum
temperature is 4 C (39 F). This will be complimented with testing within
the south-west of Western Australia where the average mean minimum
temperature during the test period ranges from 4.5 C (40 F) to 7 C (45 F).
My testing will include a combination of tent camping (warmer conditions)
and three sided shelter conditions (colder conditions).
My testing will primarily on testing the ability of the bag to retain and
provide adequate warmth within its rated range in a range of conditions and
weather. I will be using a silk liner and also a with the bag and will
test the use of the bag with and without the liners. In addition I will
also examine the:
My use of the sleeping bag was been with a silk liner (four nights) and on
the Larapinta Trail I used a Sea to Summit Thermolite Reactor liner every
Overall I have had a good experience with the bag during the field testing
phase. I have found it a tight fit around my shoulders, but not so tight as
to be uncomfortable. I have found the bag when used with the Thermolite
Reactor reasonably warm. Even on the Larapinta Trail I found I could
comfortably sleep for most of the night without wearing boxer shorts, a
thermal top, socks, and a beanie. Mind you because I tended to find the bag
a bit constrictive around my shoulders I frequently woke up at nights
finding myself partly out of the bag and getting cold. Snuggling back into
soon brought the warmth back. I did on a few nights where thermal pants
(long-johns) but really didn't find that they made much difference to my
Whilst I do feel that I reached the bags limits in terms of temperature
range when used in conjunction with the Thermolite Reactor liner which
claims to add up to 8 C (14 F) of warmth I am happy with the bag's
performance so far.
In my Initial Report I referred to a number of factors that I would test or
comment on over the test period. Those factors and my comments after two
months testing are as follows:
Functioning of the "Snag-Free Zipper Track," i.e., is it really snag free?
Long and short answer is in my opinion probably not. I find the zipper
snagging at times, but I did find that when in the bag and for example
un-zipping for a "zipper run" during the night it seemed to function just
fine, but when say zipping the bag up or unzipping for airing it would
snag. Nothing serious mind you. I really don't believe that the zipper
functions any better than other bags I have used.
Functioning of the Pad Locks. As a restless sleeper I am sure I can put
these to the test! I lasted about five minutes with the pad locks. I twist
and turn when sleeping and with this bag being a snug fit, the bag comes
with me. With the pad in the locks the pad was twisted and in the wrong
place within minutes. After untangling myself the pad was removed from the
locks and they have not been used since. Once this test is finished they
will be removed. They just did not work for me.
Functionality of the Glow-in-the-Dark Zipper Pulls - do they really glow in
the dark, does this make them easier to find in the night, does it make
exiting and entering the bag at night easier? I am starting to feel
negative about this bag, but this was (it broke on the second nights sleep
- pulled it a bit hard and it came apart) another gimmick in my view. I
really couldn't see it easily at night and have used another one that I
took of another sleeping bag. I find that I feel for the zipper so
"glow-in-the-dark" is really not adding value.
Functionality of the Chest Pocket. Is it really useful for me as a restless
sleeper; will I be able to keep things in it; find those things during the
night. My last "gimmick comment." I tried using the pocket one night, but
found that as I twist and turn during the night, find the pocket was just
not worth the effort. So this is another one of those "features" which for
me add no value to the bag.
General durability of the stitching, locking zippers, outer fabric and the
down. I have used the bag for 20 nights and it is showing no signs of
problems with the stitching, zippers, fabric or down. I have noticed some
minor feather lost through some seams, but nothing of significance. Overall
very happy with the durability of the bag so far.
Effectiveness of the draft tube in keeping warmth in and drafts out. It
works from my experience. I never became aware of any drafts via the zip
area during my testing so far. Very happy with the effectiveness of the tube.
Durability and effectiveness of the baffle construction. Do the baffles
break loose? Do they keep in the down in place? No sign of problems with
the baffles or movement of down so far. As previously indicated I am very
happy with the bag's durability.
Compressibility and lofting of the bag, particularly over 16 days of
continuos use. When I get to my camping spot for the night, I immediately
set about setting up camp. This includes putting my tent up and where
possible airing out my sleeping bag. I never had any issues with the bag
not lofting quickly and lofting back to normal state. The bag has in my
opinion had no problems with being used continuously over 16 days.
Effectiveness of the shell material to repel condensation and moisture. On
the Larapinta Trail I used my Missing Link tent which is vulnerable to
condensation and the Larapinta Trail was working over time on the
condensation production, so the bag was exposed to condensation on most
nights. I tended to sleep in the middle of the tent which kept me away from
the walls, however some nights I was less than successful and the bag was
brushed up against the tent walls. It did get noticeably wet on the
outside, but the moisture did not get to the inside of bag. I am pretty
happy with the effectiveness of the shell material.
Veracity of the claims of the shell material being quick
drying. Related to the previous comment, when the outside of the bag
got it wet, it was easy to dry. Just leaving it outside had it dry in no
time. All up I am happy the quick drying of the shell material.
Effectiveness of the liner material to wick moisture away from my body and
to prevent static-build-up. I did not experience any static and did not
notice any moisture inside the bag, so I assume this aspect was working
Thanks to Sierra Designs and BackpackGearTest.org for the opportunity to
participate in this test.