Montbell Breeze Dry-Tec UL Bivy, User Observations and Questions

[Casey Bowden]

I have yet to see any reviews of the Montbell Breeze Dry-Tec UL bivy so I thought I would throw out my 2 cents. Please note that this is the first bivy I have ever used.

Sizing
– I originally bought the standard size but found its girth to be too small. I am a side sleeper and found that the bivy really compressed my down quilt when on my side. Room was adequate when I was on my back. After upgrading to the wide and long size I had plenty of room, even with a 2.5” thick full-length air mattress inside.

Drawstring Closure
– I found the opening large enough to make getting into and out of the bivy easy. I did not find myself wishing for a side zipper. I was also pleased with the ability of adjust the closure such that only my face was exposed to the elements.

Fabric Breathability
– So far I have slept in the bivy 3 nights. Note that in all tests I slept such that none of my breath entered the bivy. The first night was on my bed with cotton clothes on. I woke up to find everything bone dry. The second night was spent on my covered balcony in temperatures that were a few degrees above freezing. Once again, everything inside and out was dry in the morning.

My third test was in Point Reyes where I stealth camped on a peak/cliff 480 feet above the Pacific Ocean. It was very, very, windy and I estimate that the temperatures where in the 40’s. In the morning I found the top of the bivy to be bone dry but the underside and my quilt was very wet. So much so that significant loft had been lost. This surprised me and made me sad as I hoped that the dry-tec fabric would be as breathable as a BMW vapor bivy and as waterproof as EVENT.

Would any bivy have failed under those very windy conditions?

Thanks in advance,

Casey
Berkeley, CA

[Scott Peterson]

I will be interested to see what some of the fabric guru’s have to say regarding this issue. I am concerned about condensation with my bag/bivy combo. and should probably try it out in a situation where failure does not mean misery.

I am concerned that a 40 degree down bag combined with the titanium goat bivy (silnylon top) will get condensation during summer trips in the high sierra…and by day 2 or 3 leave me shivering if temp.s drop.

I did not think wind would be a factor…but I wonder if in your situation Casey the humidity in the air coming off the ocean was the real factor. Intuition would lead me to think that water vapor on either side of the fabric (whether from the ocean or your body) were preventing proper transference. Obviously I have no idea what I am talking about….but my money is on the ambient humidity being the issue.

[Casey Bowden]

Scott,

You may be right about the ambient or relative humidity. One of the reasons I went to Point Reyes was to test the breathability of the bivy fabric when the top was wet. I was counting on getting alot of dew on the bivy due to the proximity to the ocean but the wind foiled my attempt. I too look forward to what the fabric guru’s have to say and hopefully a review of the bivy on BPL sometime soon.

Casey
Berkeley, CA

[Casey Bowden]

Message Deleted

[Casey Ryska]

Casey,

Other than the problem mentioned, how do you like the Montbell Breeze Dry-TEC UL Cover? I’ve been looking at it for a while and have been considering adding it to my sleeping system. However, I have been unable to find a lot of reviews on it.

[Casey Bowden]

Casey Ryska,

I purchased the bivy so I could sleep under the stars when I didn’t expect rain. I guess for this type of application I would be better off with a more breathable and less waterproof fabric. I hoped the dry-tec was a miracle fabric but it wasn’t. Oh well, live and learn.

Casey
Berkeley, CA

[EndoftheTrail]

Casey:

I have the MontBell Peak jacket which features the Breeze Dry Tec laminate. While I like my jacket very much, the dynamics between jackets and bivys are widely different.

Curious, can you give us more detail about your experience with your MB bivy? Thanks.

[Casey Bowden]

Hi Benjamin,

I have only had 3 experiences in the bivy as I outlined in the original post. After the first two trials I was very optimistic but the third trial caused me to return the bivy since my intended use was sleeping under the stars (no tarp) on rainless nights.

I didn’t expect it to breath as well as a BMW Vapor bivy but thought the air permeable fabric would work better than it did. Note that in all of my trials I slept with my face outside so none of my breath entered the bivy.

I hope that helps.

Casey
Berkeley, CA

[EndoftheTrail]

Sorry, I missed your post above (my fault). Thanks for sharing.

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