The Borah Gear Cuben Bivy is a lightweight bivy sack that’s available in several lengths/width combinations. Mine is a long-wide with Cuben Fiber (bottom) and M90 (top) with a full mesh face panel and side zipper. This is custom material combo, as Argon is what Borah Gear normally uses for the top of their Cuben Bivy’s. I’ve owned this bivy since 2013 and have been very happy with it. Here’s the scoop…
All specs as claimed unless noted otherwise…
- 78″ girth x 88″ long (allowing for a couple inches of bathtub at each end)
- #3 YKK zipper extending partially down one side
- Packed size of ~ 3 x 9 inches
- Total weight 5.3 ounces in .74oz Cuben and Momentum 90 (Long-Wide size and includes Cuben stuff sack)
- MSRP: $180
The Borah Gear Cuben bivy is one of several similar bivy sacks that they offer. The Cuben is basically one material combination (Cuben/Argon) whereas the other bivvies have several material choices, however John West was able to easily accommodate my request for an M90 top. This one is a side zipper, so the zipper extends across the chest and then down about 24 inches of the side.
I’ve been on everything from snow to sand with my Borah bivy and it’s been great. This isn’t a “storm bivy”… you wouldn’t lay out in a the rain or snow up against a rock hoping to stay dry, but it does offer a nice measure of protection from the elements when either used alone, or with a shelter. The Cuben bottom offers good protection against wet ground and should be used in combination with at least a light groundsheet to minimize the chance of punctures and abrasion. The M90 top provides some water resistance and offers protection against rain splatter, dew, and windblown snow. It’s also a very breathable material and I’ve had very few issues with condensation. When the conditions dictate that condensation will be inevitable I’ve found the amount which does form inside the bivy has been manageable (I never breath down into my bivy)… of course this can vary, but all things being equal I’ve been happy with the M90 and believe it to be a great choice in most conditions and when supplementing the bivy with a light shelter in bad weather.
The long sizing is necessary for me since I’m just over 6′-3. I believe John made my bivy just slightly longer usual since I mentioned to him that I planned to use it in the winter and would have a lot of insulation inside which I didn’t want compressed. For that reason I also elected for the wide sizing option. This gives me just enough room to fit a down air mattress, a 20º sleeping bag, and a 30-40º quilt over the top of that, for a setup that can extend to 0ºF and beyond. I’ve actually gotten to the point that I really like using the bivy even in fair weather when I’m taking a quilt. It’s like getting a warm hug from a friend! The quilt stays in place, drafts are eliminated, it adds a tiny bit of warmth, gives extra protection against the elements, and keeps the bugs out when I have it zipped up… because of the long-wide sizing, I don’t don’t get the claustrophobic vibe.
- Construction is nicely executed
- Momentum 90 is a great light and breathable top material while still offering some water resistance
- Ease of ordering and lack of up-charges for every little option
Not So Much…
- I wouldn’t really call it a dislike, but if the zipper extended just a little further down the side that would be nice.
Famous Last Words
The Borah Cuben Side Zipper is well designed and built, very light, and reasonably priced. Borah Gear has built their growing business on the platform of their bivy sales which might tell you something about the merits of these bivies. Hike It. Like It.