Choosing a Down or Synthetic Belay Jacket

I’m not sure exactly when it happened but after climbing X number of years I have changed from a gear review consumer to a gear review producer.  The only reason I mention this is because I recently found myself dispensing quite a bit of advice to a few people gearing up and I sort of amazed myself at the sheer number of pointers I could give to them.

That said, I thought I would share my thoughts on choosing an insulated belay jacket using my Mountain Hardwear Sub Zero down belay jacket and my REI brand Mountain Hardwear Compressor knockoff as references.

Before you get ahead of yourself and start thinking down vs synthetic or jacket vs parka, think about exactly what you’ll be using this jacket for.  What kind of temperatures do you think you’ll be using it in?  Then think about what you’ll be doing in those temps.  I’ve been comfortable in -5F weather in a fleece and a shell because I was hauling ass up a hill.  I’ve also been miserable cold at 40F in a windy shaded nook belaying my partner.  The reason I mention this is that no piece of gear will do everything and you should figure out what you want the gear to do before you buy the latest and greatest mountain toy.

I have both a down and a synthetic belay jacket.  My down jacket is considerably warmer than my synthetic but that was by design.  (More on that later)   The virtues of down are that it is highly compressible, its warmth to weight ratio is high and it is a durable material if you treat it properly.  The virtues of synthetic insulation are that it is cheap, provides warmth without loft and dries more quickly than down.

Now I want to say that if anybody tells you that synthetic insulation will keep you warm when wet then they are full of shit, period, end of story.  If your down or synthetic belay jacket gets wet you WILL be cold, there is no way around this.  But the nice thing about synthetic insulation is that it will dry more quickly than down and won’t lose loft like down will and therefore will work better when wet.

I bought the Sub Zero belay jacket for one reason.  That reason was I had 30 minutes to replace a stolen pack of gear and an AAI guide told me I wouldn’t regret it.  True to his word, I don’t.  The main reason I like the jacket is it works, plain and simple.  It keeps me warm, doesn’t let in drafts and is durable.  But that doesn’t help you much in picking out a belay jacket so here are some things to look for.

Hoods –  In short, get one.  Preferably one that zips off but having an insulated hood is a must in cold weather.  Bring your helmet with you when fitting the jacket to make sure the hood fits over your helmet.

Pockets – Fleece lined pockets are nice when your gloves are wet but the real “make or break” pocket is on the inside of the jacket.  Make sure there is some kind of pocket to hold a water bottle/platypus next to your body to prevent it from freezing.

Zipper – Make sure the zipper goes both ways meaning that you can have the bottom bit of the jacket unzipped while the rest is zipped up.  The is clutch when you’re belaying or roped up for glacier travel.

Weight – It may not be the lightest jacket out there but at 2lbs 4oz I’m ok with the weight.  Weight is always a factor in mountaineering but your down jacket is not the place to scrimp.  You’re obviously bringing the jacket because the weather is less than ideal and as a result it is as much a safety piece as it is a comfort piece.

Misc – The MH Sub Zero has a stretch cord on the small of the back that adjusts to make the jacket more or less fitted depending on what you need.  I think that this helps with drafts immensely.  I also like having velcro around the cuffs but that is not a dealbreaker in my book.

I also have a REI brand Mountain Hardwear Compressor.  It is a lightweight synthetic jacket that works surprisingly well.  I bought it because it can be compressed smaller than a Nalgene and can turn into an insulated vest.  Unfortunately it doesn’t have a hood but for $85 on clearance I’m not going to complain.

I took this synthetic jacket as my main insulation layer on a trip to Rainier (gear list) (trip report) and it worked wonderfully.   The synthetic insulation is surprisingly warm yet is not lofty/bulky which makes it a great layer underneath a shell which is exactly what I did to deal with the 100+mph gusts on Rainier’s summit.

I’m hopefully headed to Denali in 2010 and I can tell you with certainty that both of these jackets will be going.  It will be damn cold on Denali but the combination of a lighter synthetic sweater/jacket and a down belay jacket will cover all temp ranges from just a bit nippy to spit freezing before it hits the ground cold depending on how I layer.

Specific Recommendations:

There is a lot of quality stuff on the market so keep your eye out for good deals.  It doesn’t have to be the fanciest or the warmest it just has to work as part of your clothing system.  To help here are my recommendations based on what are perennial favorites.

Down Puffy: Mountain Hardwear Sub Zero, Feathered Friends Stuff

Synthetic Puffy: Patagonia DAS Parka,

Light Synthetic/Sweater:  Mountain Hardwear Compressor, Patagonia Down Sweater

If you have other suggestion please, please, please leave a comment.  I’m interested in your thoughts.

Dream in Vertical has a nice review of the Patagonia DAS Parka here (link)

One thought on “Choosing a Down or Synthetic Belay Jacket

  1. Bill

    You said synthetic insulation provides warmth without loft. Not true loft is the reason any insulation works.

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