Bivy:Side or Chest zip?

Chest zip is more of a PITA to get into vs. side zip in my opinion. Similar to crawling into a zipperless sleeping bag.

Yep, side zip makes it easier to get in and out of. Other than that, I can't think of any advantages. Speaking of Borah Gear, I see that John is now offering Argon in place of the M50 as a top fabric option.

Another vote for side zip for reasons already mentioned… makes getting in and out easier. Also, I really like the side zip on my Borah, however, if I get another one, I may request it to be about 6 inches longer down the side… just to make it a little easier for me…

"I see that John is now offering Argon in place of the M50 as a top fabric option."

Interesting. I wrote off M50 for bivy use due to some condensation complaints and was planning on buying one with M90. Not familiar with Argon to know if this is an improvement or not.

side zip it is then.

Hi Jason,

Like the others said, the main advantage of the side zip is easier access. I personally don't find it too much work to slide into the chest zip, but I admit, after a few years of my personal one being a chest zip, I went to side zip this last year.

As for those wondering about Argon, I am a huge fan of it so far. Although I don't have the professional equipment to test the actual breathability numbers, the Argon is every bit as breathable (maybe more?) then the already great breathing M90. Water resistance is close, with the M90 being slightly better, but Argon can still hold its own. For the splashes that these types of bivys are meant to protect from, the Argon does just fine.

The main thing I am impressed with is the downproofness. I use it in the down pants we offer, and it feels amazing and doesn't leak a bit of down. Being that it is the lightest dwr coated nylon fabric I am aware of besides the expensive sevenD, this is pretty impressive.
-John