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Reviews > Sleep Gear > Sleeping Bags > Slumberjack Vertex 20F Sleeping Bag > Test Report by Larry Kirschner

Slumberjack Vertex 20 F Sleeping Bag

Slumberjack vertex

INITIAL REPORT - December 16, 2007
FIELD REPORT - March 5, 2008
LONG TERM REPORT - April 24, 2008


NAME: Larry Kirschner
EMAIL: asklarry98 at hotmail dot com
AGE: 43
LOCATION: Columbus, OH
HEIGHT: 5' 9" (1.75 m)
WEIGHT: 200 lb (90.70 kg)

I've been an intermittent camper/paddler since my teens, but now that my kids are avid Boy Scouts, I've caught the backpacking bug. I typically do a few weekend hikes per year, and have recently spent time over the past 2 years backpacking at the Philmont Scout Ranch in Cimarron, New Mexico and canoeing the Atikaki wilderness in Manitoba. I like to travel "in comfort", so I often pack a little heavier than needed, but I'm trying to cut down. With all of my investment into these ventures, I expect my wife and I will continue to trek long after the kids are gone…


Manufacturer: Slumberjack
Year of Manufacture: 2007
Manufacturer's Website:
Model: Vertex 20 F (-7 C)
Size: Regular Right
MSRP: Not listed. Approximately USD $109.00
Listed Weight: 3 lb, 4 oz (1.47 kg)
Measured Weight, including stuff bag: 3 lb, 3 oz (1.45 kg)
Dimensions as provided (stuffed): 9 x 12 in (23 x 30 cm)
Dimensions as measured (stuffed): 9 x 13 in (23 x 32.5 cm)


The Slumberjack Vertex came packed in its stuff bag, which is made out of the same nylon as the bag itself. The sack, which is really a compression sack, was not cinched down, and the bag was actually neatly rolled inside. It was a tight fit, so it took a few minutes of tugging to free the Vertex for examination. The photo shows the bag in its sack before cinching. As hard as I tried, I could not quite get the stuff sack to compress to 9 x 12 in (23 x 30 cm), but there was still some give to the bag, so I don't think it would be trouble to squash it another inch in a backpack.
vertex in bag

After unrolling the bag, I laid it out to get some first impressions. The bag has a right zip, which I suppose means it is located on the right side if one lays on the back. The colors are listed as Dark Navy, Rage, Stone, and Charcoal, which in lay-terms translates as blue, silver and orange (see the photo at the top of the review). The back of the bag is solid dark blue except for the hood, which is orange. The bag is filled with Climashield XP, a synthetic continuous filament insulation, which is advertised as being warmer, lighter, more compressible, and more resilient. These fibers are also supposed to be more moisture resistant and to dry quicker than other synthetics. The lining of the bag is a polyester taffeta, which didn't seem unusual in any way to my touch. The outside of the bag is nylon diamond ripstop and polyester pongee, whatever that is. The bag can be washed in a front-load washing machine, and I think it rather handy that this information is printed on a label that stays attached at the foot of the bag.

The bag comes with a printed insert explaining its features, so I took the opportunity to examine them, starting at the top and working my way down.

The bag has a mummy hood, which can be flipped inside-out (right of figure) for warm weather camping. When the hood is flipped over, it doesn't have enough bulk to be a good pillow, but I don't think that is really the point of this feature. At the right shoulder (same side as the zipper), there is a Velcro panel which can be closed to keep the bag zipped all the way up. At the left shoulder are the drawstrings for the hood (see the arrow in the figure). The two strings are different colors and different shapes (one is flat and the other round), so that they can be differentiated in low light or by touch. One string controls the front opening of the hood, and the other controls the top opening of the bag itself, so that the head opening could theoretically be adjusted to different shapes, if one were so inclined. There is a barrel clasp for the strings, which seems to function fine.

vertex hood

Regarding the zipper, it is three-quarters length, with the capability to open from either the top or the bottom. The main zipper has separate pull tabs on the inside and outside of the bag, and the outer pull-tab has a cord to make it easier to use. All zippers were tested and seem to function well. Inside the zipper, there is a draft tube aimed at blocking cold air which is joined to the outer wall by a fabric bridge just below the end of the zipper. The sleeping bag also has a small pocket with a Velcro fastener located in the chest area on the inside of the bag. The pocket is approximately 4 x 4 in (10 x 10 cm), and is described as a 'media pocket for keeping small items close at hand'. It is a little hard to see in the photo, so I have marked the approximate position with the red lines.

vertex features

Finally, the bag is described as having a trapezoidal footbox, which means that there is a small amount of extra fabric at the bottom which allows the feet to rest heel down with enough room for the toes not to feel cramped.

vertex footbox

In addition to examining the features of the bag, I did a close examination of the construction of the bag. In general, I observed no flaws, although there were some areas of loose threads at a few places along the zipper. I will keep an eye on these areas as I go through the testing process and see if there are any real concerns there.

fraying 1 fraying 2


I haven't tried the bag out on the trail for this IR, but I did climb inside to get some first impressions. Overall, I would say that the Vertex has a nice roomy feel on the inside. As may be appreciated from the photos above, the bag has a fairly wide chest area, and is much narrower in the hips and leg area. Given my body shape, (broad shoulders, and probably a little too broad at the waist at the moment--see my specs above), I found that there was plenty of room for me to lie comfortably. There was also plenty of room from head to toe, so I think that choosing the Regular size bag was a good choice for me (at 5'9" /1.75 m) rather than the Long size. I wasn't sure if I would notice the trapezoidal footbox, but I could definitely tell that my feet and toes had more room in the Vertex than in other mummy bags I have tried.

I ran the zippers up and down a few times without much trouble, although I did find it a little challenging to zip/unzip the bag from the inside. The cords controlling the hood and storm collar functioned fine.


The Vertex sleeping bag appears just as it does on the website, so I would have to say it is currently matching my expectations. The only thing I found surprising and somewhat disappointing is that it did not come with a storage bag like my other sleeping bags. It has loops on the footbox for hanging, which would be the preferred method of storage. However, as closet space remains at somewhat of a premium, a storage bag would have been appreciated.


With the end of the year looming, I am done backpacking for calendar 2007 year, but I expect to start again early in 2008. From now until the conclusion of this test, I plan on using the Slumberjack Vertex as my primary sleeping bag for any and all upcoming trips. I have weekends out already scheduled in mid-January, February, and March, and expect to continue through the spring. The trips are planned for central Ohio, and may involve temperatures anywhere from 10 F (-12 C) to 50 F (10 C) at night, with the most likely scenario near the middle of that range. If I am lucky, I may see some snow on one or two of the trips, but it's impossible to predict. After I use the Vertex, I definitely plan to throw it in my washing machine and see how it holds up.

This concludes my Initial Report on the Slumberjack Vertex 20 F Sleeping Bag. Please check back in 2 months for my Field Report on this item.

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March 5, 2008


To date, I have only used the Vertex on one weekend trip, which was a winter survival expedition in Findlay, OH. On the first night, I stayed in an unheated cabin, and the temperature inside was about 25 F (-4 C). On the second night, I stayed outside under a shelter, and the temperature reached 0 F (-18 C). It was cold


The first night I spent in the Vertex was 25 F (-4 C), very close to the bag's rating of 20 F (-6.6 C). I wore my usual sleeping gear (thermal shirt, cotton scrub pants, wool liner socks) with a pair of heavy wool socks on top. With that combination, I was pretty cold most of the night, particularly on my feet, even with the two layers of socks. Although I would have liked to have been warmer, I didn't think the performance was unreasonable for a bag of this rating, and if I had really wanted to be warmer, I could have worn more layers on the inside.

Aside from the question of insulation, there are some other aspects of the bag that deserve comment. First, using this bag in the field definitely confirmed my initial impression that it is very roomy on the inside. When I was settling in the bag, there was a substantial amount of room on the inside for me to roll over and such. There was also a lot of room for my feet, which I expect would be better in the warm weather, but didn't allow me to really wrap my feet up in the bag's footbox. This extra air within the bag may contribute to some extent to the bag feeling cool, particularly in temperatures this cold. I used the pull tabs for the collar and hood to pull the hood opening shut. When this was done, I did not notice a lot of air leakage in from the side, indicating that the draft tube worked fine. Even though this is the regular size bag, I also had plenty of room to scoot down so that my head was really below the level of the neck collar. When I sleep crunched down like this, I did not notice any condensation on the outside of the bag, which suggests that the bag transfers moisture very efficiently.

On the 0 F (-18 C) night, I did not think it safe to use this bag exclusively, so I actually took my other 20 F (-6.6 C) bag and used it as a liner within the Vertex. Again, the interior roominess allowed me to do this easily, and I didn't feel any more constricted than I do when I have slept in that other bag by itself. Using the two bags together at 0 F (-18 C) actually kept me warmer than the Vertex itself at 25 F (-4 C), but I think this is not really a fair comparison. (Note the difference in thickness between the Vertex with another bag inside it (on the left) compared to my friend's 0 F (-18 C) bag with a liner (on the right))

vertex setup for night in shelter


So far, I have not noticed any significant wearing of the bag, although the use has not been extensive (yet). Of the areas with the pulled seams noted in my initial report, I am happy to say that those areas have not progressed, and they basically look the same now as when I first received the Vertex.


To date, the Slumberjack Vertex has functioned quite well. The most striking feature of this bag is its roominess, which has its plusses and minuses. The draft tube and hood do their jobs well, and the overall feel of the bag on the inside is quite comfortable for sleeping.

Overall, I have been happy with the Vertex sleeping bag so far, but I am hoping that spring and slightly better camping weather arrive soon so that I can spend much more time inside it. My plan is to continue to use the Vertex exclusively over the remainder of the test period so that I can get a better sense for its sturdiness, as well as its ability to function in more reasonable hiking/camping conditions.

This concludes my Field Report on the Slumberjack Vertex sleeping bag. Please check in back in about 2 months for my final report on this item.

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April 24, 2008


I have used the Vertex 5 additional nights over the long-term testing phase of the report. One of these was a 3-day trip to southern Michigan, where I did some cabin camping. The overnight low temperature on that outing was about 65 F (18 C). For my other trip, I spent a weekend hiking in Cuyahoga Valley National Park in the Akron (Ohio) area. Although there were tornados in the area, I (fortunately) had generally quiet nights where the overnight lows were around 45 F (7 C). Thus, during this test, I have had the opportunity to test out the bag at a full range of temperatures.

In general, I am not a person who likes to be especially warm at night, and I tend to sleep better in cooler temperatures. As I noted in the Field Report, I was quite cold in the Vertex at 25 F (-4 C). Although it wasn't nearly as bad at 45 F (7 C), I still felt a little cold at this temperature, especially my legs and feet. I did not feel that the bag was drafty at the site of the zipper, but I just wasn't as warm as I would have liked (despite using my usual self-inflating pad and sleep gear for the weather). In contrast, the bag was extremely comfortable at 65 F (18 C). It kept me warm without being too hot, and I slept really well under those conditions. I think part of the problem for me with the colder weather is that the bag is so roomy on the inside, there is too much dead space which didn't warm up, even after being in the bag for a while (i.e., when I woke up during the night to roll over, I felt cold).

On the positive side, when I woke up in the dark, it was very easy to find and manipulate the drawstrings for the hood to reduce my head exposure. I also noticed that there was no noticeable condensation on the outside of the bag, even when I slept with my head fully inside. I attribute this to good wicking behavior of the fabric as well as low moisture retention. I have not had issues with the zippers, which have worked well, even when I didn't open my eyes to adjust them.

Regarding the bag's durability, none of the loose threads I noted in my initial report have pulled to any extent, and inspection of the bag does not reveal any new areas with loose threads. Based on my experiences to date, I would say that the durability of the Vertex is fine. If I hadn't specifically been looking for defects when I received the bag, I probably wouldn't have noticed anything, and there is nothing I can see now after having used it for a couple of months that makes me concerned about this.


Overall, I found the Vertex to be a reasonable bag, and would recommend it to anyone who likes to have extra room to move around inside a sleeping bag (or who needs extra room to accommodate his/her girth). Based on my experiences, I will likely continue to use this sleeping bag on a late spring/summer/early fall trips where the weather will be warm; however, I would be quite concerned about taking it to the backcountry if the temperatures forecast included anything in the 30-40 F range (-1 to 4 C), or even the mid 40's F (5-8 C). Given the fact that I didn't think the Vertex kept me especially warm, I think the bag is a little bulky. If the forecast were for very cold weather, this item would make a great outer bag to be used with another sleeping bag inside (as I did during my Field Test period).

Things I liked about the Slumberjack Vertex Sleeping Bag:
  • Very roomy
  • Easy to stuff
  • Hood apparatus and cords work well
Things I disliked about the Vertex:
  • Really did not seem as warm as its rating
  • I would have liked it to come with a storage bag

This concludes my report on the Slumberjack Vertex 20 F Sleeping Bag. My thanks once again to Slumberjack for providing this equipment for testing, and to for allowing me to participate in the evaluation process.

-larry kirschner

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