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The cold world of skimo & alpine climbing

The cold world of skimo & alpine climbing

Thursday, February 3, 2011

Arcteryx Atom LT Hoody....just how good is it?

Jim asked,  "You have mentioned that you use the Atom LT.  I looked at one in the store and really liked it, but two things stopped me.

What is with the stretch side panels? I haven't seen this on any other parka. Seems like this would cost warmth with little upside.

No hood adjustment at all. WTF? Seems like this would be a huge PITA. Doesn't this make the hood next to useless?"

Yes the Atom LT is one of my main stay pieces for cold weather climbing.  And one of my better investments in awhile for my own gear. I have and use two of them constantly. The vents are critical for using this jacket/sweater and do allow you to use a super light weight (as in .oz)  insulated garment  that is a lot warmer for the weight than anything else I can think of,  because it breathes so well. Wild Things and Mtn Hardware have now copied the technology/design for their own versions. Hood is actually very good!  No issue what so ever and easily fits over a helmet. It is extremely user friendly in fact.

The down sides?  The shell material doesn't fair well rolling around on hard mixed.  Rock climbing, chimney and off width, will shred them pretty easily.   Soft shells are the weapon of choice there.
The stretch panels?  They aren't very wind resistant.  A lwt wind shirt under the Atom Lt will up the warmth in a cold wind.  But the Atom is still no belay jacket imo.  It is a climbing garment not a belay garment in cold weather.  Think sweater, not jacket.  The zipper?  I had it pointed out to me that the zipper has no lock on it.  Intentional by design to make it last longer I was told.  I'd been using the Atom Lt for a year before I realised this fact.  Read it actually.  Loaned a buddy one of my spare Atom Lts and he hated the zipper.  I have never, ever noticed it.  So no down side for me at all.  But worth knowing.

And the Atom LT can be used as a mid layer easy enough in the rock climbing situation to beef up the temps a soft shell can be used in with some comfort.  The Atom LT's pattern and trim fit help there.  It isn't the most intuitive way to layer (with a wind short or soft shell) but it works for certain projects.

Weight comparisons?

Lightly insulated jackets (belay sweaters) and shells:

EB Downlight Hoodie Pullover XL 15.4 oz   455g
EB Frontpoint XL 18.5oz   547g
Arcteryx Atom lt Hoody large 14.4oz   429g
Arcteryx Atom Hoody SV 19.0 oz   562g
Mtn Hardware Compressor Hoody 19.8oz   586g
Arcteryx Gamma MX Hoody XL 24oz   710g
Arcteryx Squamish pullover XL 5.6oz   166g

On that list only the Compressor, Atom SV and EB Down Hoody are warmer.  All are a tiny bit heavier and generally too warm to climb in alone as the 2nd layer because.....they don't breath nearly as well as the Atom LT.   I will most typically add any of those three as a third layer when belaying or for climbing (more likely descending) when it is really cold out or the wind comes up.

It is a green Atom Lt in this picture with the black Compressor Hoody jacket used as my belay jacket over it.  Pretty cold belaying in this picture and then again, I peeled the Compressor and just climbed in the Atom LT and a R1 hoody.

The Atom lt can be a mid layer for warmth. But I use it generally as a outer shell garment for cold weather climbing when I am very active. I no longer use a mid layer   Some type of Hoody on the skin,  likely a SAG Khushi, NWAlpine Hoody or R1. Then my 2nd layer, generally a Atom LT or a shell garment like the EB Frontpoint or a soft shell Arcteryx Gamma MX.  The Atom LT (or anything similar in weight like the Nano Puff)  is NOT a belay jacket...more a "belay sweater" and not that warm in the grand scheme of things if you are going to use it like that. Which I do if the temps permit it.

More here on what I think is a better layering system.

In the Ice fields late Nov. Good wind blowing while we discuss the avi conditions.

The Joke Slinger in his Atom LT at -20 something when the extra venting under the arms is crucial.

Another pretty cold day and in the shade.  But that is the point, the Atom LT allows you to climb in relative comfort (and it was "relative comfort" on this day in lwt single boots) on some pretty cold days.

More here on the idea of a climbing sweater.


Anonymous said...

Dane, I've been using a 60g primaloft jacket over an R1 hoody this winter. Works great but I'm wondering how well the insulation will stand up over multiple days of climbing. Do you find that it collapses after a day or 2 w/o drying out indoors?

Dane said...

I've used Primaloft 1 even more than the Arcteryx stuff. And either insulation is what I would first choose for any multiday climb. As long as you aren't shredding it on rock either is likely the most stable and protective insulation we can take to the mtns.

Myself and my partners have soaked our Atom LTs, then had the shell freeze on us and easily dried them with body heat while climbing, many times over. And most importantly had virtually zero change in insulation value.

Your comb is the best set up I have ever used for cold weather climbing because you can so easily stay warm and dry..for short or long duration projects.

Take a look at what Colin Haley used to solo the Cassin and for Dracula. He and I have never talked in detail on clothes but looks to be the same set up.
So good guess the combo works for 70 or hrs anyway :)

Anonymous said...

Dane, Thanks for the quick reply and link as well. 70hrs straight is well beyond what I'm likely to do. Great blog on the CCW packs also. My favorite as well!

Jim Thomas said...

Dane, great stuff! I was about to post again on SummitPost, but you addressed most of it here. Glad I looked. Right now, I have the following: R1 Hoody, Nanopuff pullover and Houdini (plus a Pata Stretch Ascent for rain). I was about to get a down hoody, but have decided to go synthetic. So I am looking at either an Atom LT or a Nanopuff Hoody. One of the blogs (Haley?)showed people using a Houdini over the R1 and then a Nanopuff sweater over that. Does this make sense? The Houdini would block wind if you took off the NP pullover, but I am wondering about breathability. So to summarize for Baker/Adams/Rainier: R1 Hoody - Houdini(?) - NP pullover - Atom LT or NP Hoody (?) + ? on top for summit/stops/camp. Thanks for all your input.


Dane said...

>I was about to get a down hoody, but have decided to go synthetic.

Hey Jim, good choice and thanks for the topic idea!

> One of the blogs (Haley?) showed people using a Houdini over the R1 and then a Nanopuff sweater over that. Does that make sense?

Yes I do the same with a Arcteryx Squamish hoody simply because the Arcteryx stuff fits me better.

>The Houdini would block wind if you took off the NP pullover, but I am wondering about breathability.

That is the key and I suspect the Houdini breathes well enough but haven't used one to comment. Remember Colin's photos are on Denali...good bit colder than Rainier :)

> So to summarize for Baker/Adams/Rainier: R1 Hoody - Houdini - NP pullover - Atom LT or NP Hoody on top for summit stops or camp.

You might be over thinking it. R1, Houdini, then a synthetic sweater layer of your choice (Atom LT or Nano Puff hoodies) and then a 100g belay jacket. The final layer I would prefer is a Patagonia Micro Puff or a Atom SV but I have used a MTH Compressor hoody as this layer until just recently.

Depending on the forcast and my intended route and time frame I might not take that last layer on a Rainier summer climb. Or I might just add a lwt hooded down sweater.

Brian said...

Jim and Dane: I was going to use about the same system, Patag R1 -> Arcteryx Windshirt -> Nano Puff hoody. However, when I got the Nano, I found that the hood was WAY too small to go over a helmet. Now I'm a skinny tall (6', medium Nano) person so it may not be an issue for shorter people who are going to wear a larger size, but the hood wasn't even CLOSE to fitting me. As such I've decided to get the pullover version and ditch the hood. I think this is what Haley appears to be using too if you look closely at the photos. So I would make sure the Nano hood works for you before you buy. Just a thought.

Dane said...

Thanks Brian. Good thought! I made a trip to the local Patagonia store and tried on both the Nano hoody and the Nano pull over shirt. Different patterns for those two from my experience. Pull over fit like a sweater. The hooded zip front like a smock..a big smock.

Pays to remember Colin gets his Patagonia gear for FREE. So I'd assume he uses the best they offer for his use. Which may not be the best available for that same use.

akalpinist said...

Interesting this timing for this topic to pop up. I've been using the Nano line for awhile now and have been very impressed. My DAS used to be the redheaded step child I always frowned at but loved, always up to the task.

Last weekend I was out in Juneau Icefield on wall with no sun and opted to go with a Nano Hoody, M10, R1 and Merino T. It was awesome. I kept the Nano on the same biner as my belay mitts on my harness it was hardly noticable.

I am headed to the Ruth in April and Peru in June/July and was thinking of trying to go with the Nano Hoody on route. I was looking at the Atom line as well. I'm glad to see others are having similar experiences with these lighter systems.

They do however leave you screwed! if you get hurt and/or have an unplanned bivy.

Dane said...

"They do however leave you screwed! if you get hurt and/or have an unplanned bivy."

Pretty much. I keep saying "sweater" not belay jacket let alone something I want to spend a cold nght out in Alaska in May. April...NFW. I'd want a Duelly, DAS or something similar until mid June.

Anonymous said...

I agree with the above - 60g primaloft, R1 hoody and R2 vest was NOT enough for an unexpected summer bivy in the CDN Rockies!
Since them I've been carrying a bothy bag and slightly warmer (100g) jacket.
Seems to me that these new 60g products are really a fleece replacement. They do not replace the need to warmer/safety gear if your getting on something big/challenging.

Cosmin Andron said...

Hi Dane!

how about this combo: Rho AR + Atom LT Jacket (not hoody) + Gamma MX hoody (and a Dually in the backpack).

The Gamma stands up abuse extremely well while being breathable and windproof - my fav outer garment. The Dually is lightweight and handy - I always ski or winter-climb with a stripped BD Speed backpack (to keep the Dually and a snack doubled as back protection).

I prefer, for outer clothing Arcteryx for its athletic cut (I am rather tall and slim - 5'11" - 144lb). Also Arcteryx makes the only clothing I tried that stays put in the harness ever after wiggling silly in a chimney...

Dane said...

Cosmin! How can we trust a suggestion from anyone who solos the Cassin? :-)

I like your combo and agree on the MX. It will take an incredible amount of abuse.

Unknown said...

HI dane, thanks for all the info. Whats the skinny on the new Wild Things line?? I drop in there almost once a week on my way to climbs in NH and they don't have much info. I know theyve pushed the launch dates way back, as far as fall 2011. You have any insider info??

thanks again,

Dane said...

I don't know much. I was told at OR that many of the older WT designed packs were available now via the NH store or mail order. All of the newest products they were showing at the OR show would typically be first available Fall of 2011.

But never hurts to call and ask. Should make them feel loved. I suspect they are ramping up to become a "climbing specific" dealer again and aren't there yet.
Hopefully they will be again soon.

arcteryx jackets said...

Nice pictures. Thank you for sharing this great article. Hope to read more from you. Keep it up!

Anonymous said...

Hi Dane,

It may be a little late to ask for your input from an older post; however, I'm in the market for a new jacket and I like your comments on the Arcteryx Atom LT Hoody. I also looked at the Atom SV Hoody (I only looked at both jackets on the internet). Do you know the difference between the two jackets? Is there any advantage of using the Atom SV in cold, damp conditions over the Atom LT?

The reason I ask these questions, I will be climbing in Vermont (Lake Willoughby) and New Hampshire for five weeks this winter, between January and February and I want a jacket that will perform in cold, and sometimes windy, and damp northeast conditions.

Thanks in advance for any help or advice you can give me.


Dane said...

Larry, the Atom Lt is truly just a sweater. The Atom SV an excellent mid weight belay jacket made to layer over the Atom Lt. Sounds like you want the here on both just use the search function.

Alex said...


I read on Patagonia's site that 60 grams of Primaloft are as warm as an R2 fleece, so theoretically, would the R2 under a windshirt be as warm but more breathable than the non hooded Atom with only a slight weight penalty ? Or fleece is dead for good and I should get over it ? I am currently looking at Wild Things Insulight(Atom clone) but breathability is a major concern, I'm an overheater.

Anonymous said...

Have you tried on the WT Insulight? I notice in the pics you don't actually climb with the hood on too. Seems like the WT is more wind resistant in the stretch panels and tougher fabric too, not sure on weight difference. Would love to see a review as I'm looking at getting one or the other. Not sure whether I really need a hood. Was tending towards the Atom Pullover or the WT.

Dane said...

I use the hood all the time on the Atom of the reason the LT is so useful.

Anonymous said...

used the LT hoody ice climbing at the apron yesterday in the snow with the ice melting all around me. I am now a true believer, this sweater kept me pretty dry and absolutely warm. Had a 100 weight fleece and the patagonia sun hoody underneath and could not have been more comfortable.


Father hooded sweatshirts said...

Nice stuff.
Thanks for sharing this.

Anonymous said...


Thanks for all your efforts that benefit the climbing community.

A quick question on the Atom LT/synthetic insulation generally: how do you keep yours from losing its loft and (presumably) its effectiveness? I have an LT and it is as flat and thin as a pancake after ~1 year.

I wash it with down wash, etc. Thoughts?

Dane said...

Atom Lt? But this is also what I do with all my clothing so I don't loose loft or the DWR any quicker than required. I wash mine sparingly. May be once a year..seldom more. Less if possible. I go by the smell test. I also dry them in the drier hoping to rejuvenate their loft. But to be honest so far I have gotten rid of my Atom Lts after 3 seasons of use and gotten new ones. So I am not the guy who can tell you how durable they might be long term. I like them enough that recycling them seems reasonable to keep the perfoirmance. Not something I would/could have done earlier because of the costs.

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Anonymous said...

I've been using the LT for a year now, based on your blog. It's pretty much the only piece I wear besides a shell.
Use it for ski touring as a jacket, and on the downhill throw a shell over it. The only problem I have is the sleeves are too heavily insulated when you're using it under a shell. Arms get sweaty.
I've steam ironed the sleeves to make the loft thinner there for my purposes. For climbing this may not be an improvement but for skitouring it is.

Blerger said...

Glad to see you like it, I love my Atom. You're right it is not a belay jacket, or intended to be, but a warmer layer for active use. I use mine all year round and find it very versatile.

AC said...

I've owned at least a dozen 60g synthetic jackets in recent years and the Atom LT is my favorite by far. The primary reason is fit. European brands like Rab and Mammut are cut way too small and feel restrictive. Black Diamond has these tiny collars that strangle me. Patagonia sizing and fit just don't work well on my body. Arc'teryx is the one brand that has sizing dialed in and near perfect for my height and weight; 5'11/200lbs. Though I must admit, the Cotopaxi Pacaya is near equal to the Atom LT, and the fit is svelte.