Sleeping in a bivy has always seemed a little too claustrophobic to me; a little like those pod hotels they have in Japan. So it was with a little trepidation that I ordered my first bivy a few months ago, having made the transition to using tarps and single-wall shelters. How would I cope with what I felt was a constricting form of protection?
Katabatic Bristlecone (image from Katabatic Gear)
Bivy bags come in different forms - for stand-alone use, for use under a tarp, or for protection while sleeping precariously halfway up the side of a mountain face. I have no interest in the latter; my bivy bag needs to protect me from condensation on the inner wall of my DuoMid, or from blown rain or spindrift finding its way under my SpinnTwinn.
Stand-alone bivy bags are more like mini tents; they offer full protection from the weather, be it wind, rain or snow, while offering breathability to allow perspiration to escape without forming condensation inside the bivy. This requires a lot of work from the material, the current favourite being eVent.
falls clearly in the category of bivy's designed to be used under a tarp. The upper material is Pertex Quantum, a lightweight, water resistant material with exceptional breathability. According to the manufacturer it is "ideal for situations where high water resistance isn't as important as breathability or weight savings."
Somewhere in there is a Brislecone...
For this reason, the Bristlecone is best used under a tarp or in a single-wall shelter unless you can be absolutely certain that it won't rain. The design Katabatic have employed for the bivy reiterates this. Rather than making the hood section completely from Pertex Quantum, it features a generous no-see-um mesh which offers an almost 180 degree window around your face once safely zipped up inside. This window, for me, goes a long way to alleviate feelings of claustrophobia. I find it very enjoyable to be able to see what is going on around me during the frequent interruptions to my sleep that I usually experience out in the wilds.
There is an art to making bug netting windows, however, and Katabatic exceeded my expectations in this design. Usually, manufactures offer either very tiny mesh windows, or full mesh hoods, neither of which appeal to me.
My previous bivy, the TiGoat Ptarmigan, has a neat convertible hood, but the tie-out loop on the mesh was attached directly to the netting - one of the weakest points in the bivy. Bug mesh is fragile and easily snagged or torn at the best of times. On the first night I used the Ptarmigan, the tie out loop ripped a big hole in the bug netting, and I became very, very upset.
The Bristlecone addresses this issue with an elasticated tie-out loop attached above the zipper in the hood. It is sewn into the far stronger zipper material, and is thus able to handle much more stress from the inevitable rolling around, zipping, unzipping and general tugging undergone while adjusting it during the night.
Bristlecone hood (image from Katabatic Gear)
Tying up the hood lifts the bug netting off your face, and simultaneously raises the Pertex Qualtum area of the hood to create a barrier against blown rain. The water resistant area faces the weather at a steep angle, so water rolls easily off. The netting side angles down towards the rest of the bag, increasing ventilation by allowing warmer air to rise up the inside of the bag and escape. Perfect.
Lying on my POE Ether Elite and Kooka Bay air pillow, I found that the bug netting just touched my nose while on my back. However, I do have a large nose(!) The feel of the netting was not unpleasant, however.
Another design consideration I appreciated was the zipper, which extends across and half way down the side of the bag, making it much easier to climb inside. I did have one problem with the zip. Somehow, when I unzipped it, I managed to tear the small piece of fabric acting as a stopper. This then came completely unstitched, and the zip fell off.
This wasn't such a big problem but I was surprised as in all other aspects this is an almost perfect piece of gear. I don't recall unzipping particularly hard, so in all likelihood it was probably already weakened. I was able to re-attach the zip quite easily. At Katabatic's request I've sent the bivy back for repair or replacement. It was the only problem I had, but I can see it happening quite easily. Katabatic might want to use a stronger piece of material as a zipper stop in the future.
-- UPDATE --
Aaron at Katabatic emailed me today to say that they will be adding a reinforcement to the zipper stop on all bivys made from this point on. It's so great when a manufacturer responds to feedback and makes amendments to the design.
-- END UPDATE --
The base of the bag is waterproof silnylon, and all I can say is that it did its job very well. I found that my Ether Elite slid around like crazy on the silnylon. I ordered a long version of the bivy (198cm) and I hoped that the Ether Elite, also 198cm, would just fit nicely inside it. However the Bristlecone was still longer than the sleeping pad by some 20-30cm, which isn't a bad thing: it provides room to stuff extra clothes if needed. I like to stuff my down jacket above my head for example, so I can grab it if the temperatures drop too far at night.
So, with this extra length, the pad still had room to move around. I tried attaching dabs of SilNet to the underside of the pad, hoping that they would stop it slipping, but they didn't adhere to the pad's material very well, and have now all peeled off. Another solution was quickly improvised. Katabatic have added attachment points inside the Bristlecone for their quilts. I use a GoLite Ultralite quilt, which also comes with attachment points and some webbing. I took the webbing, slipped it through the clips on the Bristlecone, and secured the Ether Elite that way. This worked pretty well. The mat no longer slid around.
Another problem I faced with the Ptarmigan bivy was that there wasn't much girth to allow for my thrashing around at night. I'd get it all twisted up around me. The Bristlecone, although advertised as having the same girth, was in fact much more roomy.
The Bristlecone also has stake-out loops on each corner. They are not attached particularly securely - there is no reinforcement - so they won't cope with a lot of stress or tension, but I tried them with great success. I staked out the two corners in the hood to stop the bivy from sliding around on the polycryo ground sheet and it worked a treat. I could side-sleep and turn without that annoying feeling that you are going to wake up somewhere else.
The most important question still needs answering: did it keep my quilt free from condensation? The simplest answer: yes. Each morning the interior was dry. On one particularly cold and dewy morning I felt what might have been a very slight patina of moisture on the inside. This was probably because I snuggled up in my quilt, pulling it over my mouth, which would have increased the moisture at the top of the bivy. My quilt felt dry, so it was probably my imagination.
As for the exterior, it easily shed any condensation picked up from the shelter walls. Water beaded up and rolled off instantly. I'm confident that even with sustained contact it will keep everything dry inside. The stake-out loops can also be used to hang and dry the bivy if necessary, but I found it dried in the shelter while I ate breakfast.
The 198cm (6'6") Bristlecone costs $149 from Katabatic Gear, and weighs in at 200g. One nice thing is that the price is the same for the regular and long version - I wish more manufacturers would spread their costs this way.
To summarise, the Bristlecone is a high-quality piece of kit, and I look forward to using it again.
-- Updated to include info on zipper stop design modification by Katabatic --