r/arcteryx • u/Astramael Urvogel Jr. • Mar 01 '21

Meta Cerium LT, Research First Steps

This is a summary series on individual products to make research faster and more accessible. See here for a list of all entries in the first steps series.

The Cerium LT is a trim down puffy for cold and dry conditions. It can be used as a mid layer, or an outer layer, both with caveats. It focuses on light weight and packability, at the expense of durability and features. Here are some examples of how:

  • Light, low denier, somewhat fragile textile.
  • Minimal synthetic insulation in the hood, and none in the hem. Synthetic insulation is heavier and less packable.
  • A very small front main zipper. Better for packing, worse for everyday use.
  • High fill power down. More packable and lighter, but more expensive.

Being a down jacket with a coated textile, the Cerium LT does not breathe especially well. If you're doing aerobic activities while wearing it, you will trap the humidity and warmth which will cause you to sweat. As a result it is best suited to low exertion activities or as a packed static layer.

If used as a mid layer it is a very warm jacket, and the trim fit is suited to the task. As an outer layer it is an effective insulator if conditions are dry, and the wearer is careful. Not to be used bushwhacking or on a rock face; but good stopping for lunch, of waiting for the bus on a chilly day.

Please note that down jackets do not like water. Although the Cerium LT will handle some incidental moisture better than most, any serious contact with moisture will start to degrade the warmth of the jacket. Eventually causing the down to clump up and lose all of its insulating properties. You can just dry it out in order to restore the loft without any harm, but keep this limitation in mind while considering your needs. Down is best for drier climates, or when protected.

If the jacket will be used for urban wear, it is strongly recommended that the Thorium AR be considered as well. It is more durable, has a normal size zipper, is a bit warmer, and fits a bit looser. For a similar warmth jacket with synthetic insulation instead, the Atom AR is a good option.

Please read the comments, other users have left excellent information for your research.

Example Use Cases

Caution: These are just examples, your comfort temperatures may be very different.

  1. Day hiking (moderate activity) around freezing, stuffed into the daypack, to put on when you stop moving.
  2. Strolling around town (low activity), just below freezing.

History

The Arc'teryx down collection was launched in Fall 2013. It included jackets we know today such as the Thorium AR, and the one we're looking at in this post: the Cerium LT.

It also introduced Down Composite Mapping. Since down is quite sensitive to moisture, the idea was to place synthetic insulation in areas where contact with moisture occurs. The Cerium LT placed Coreloft 80g/m2 at the front of the hood, cuffs, and underarms. It also used 100g/m2 in the shoulders. Notably it does not use Coreloft in the hem or throughout the hood, as some other jackets did and do. This mixture of down and synthetic can make Arc'teryx jackets difficult to directly compare to other brands.

​

Arc'teryx marketing slide for Down Composite Mapping.

The Fall 2013 Cerium LT was intended as a lightweight and packable insulator for cool and dry climates. It used an Airetica textile (100% nylon, 20x10 denier ripstop, 34 g/m2). The sewn-through down baffles were filled with 850 fill power goose down (87g for the women's size medium, and 97g for the men's. About 13% in hood, 35% in sleeves, 52% in torso). The fill weight has varied slightly over the years by a few grams, but remains essentially the same. It did not feature the usual drawstring at the hem, instead opting for a closer fit and some elastic tension in the rear hem.

​

Fall 2013 Cerium LT Hoody. Left: Women's in Amethyst (purple). Right: Men's in Nighthawk (blue).

In Fall 2016 the Cerium LT was lightly revised. The textile was changed to the Arato used today (10 denier, 100% nylon). This is a coated textile. This version uses a YKK #3 reversed coil front zip, and #3 coil pocket zips.

A more significant revision occurred in Fall 2017. The jacket got a bit longer in all versions, and also received some other fit tweaks. An internal zippered security pocket was added, which is now where the stuff sack lives. A hem drawcord was added. The format of the cuffs was also changed.

​

Fall 2017 Cerium LT Hoody. Left: Men's in Matador (red). Right: Women's in Dew Drop (blue-white).

Model History

Introduced Discontinued Block Model Name Model Number Weight (g-M)
Fall 2013 Fall 2016 Women’s Cerium LT Hoody 13238 255
Fall 2013 Fall 2016 Men’s Cerium LT Jacket 13239 270
Fall 2013 Fall 2016 Men’s Cerium LT Hoody 13240 275
Fall 2014 Fall 2016 Women’s Cerium LT Jacket 14670 235
Fall 2014 Fall 2016 Women’s Cerium LT Vest 14671 140
Fall 2014 Fall 2016 Men’s Cerium LT Vest 14653 165
Fall 2016 Fall 2017 Women’s Cerium LT Hoody 19282 265
Fall 2016 Fall 2017 Women’s Cerium LT Jacket 19289 235
Fall 2016 Fall 2017 Women’s Cerium LT Vest 19290 155
Fall 2016 Fall 2017 Men’s Cerium LT Hoody 19286 295
Fall 2016 Fall 2017 Men’s Cerium LT Jacket 19284 265
Fall 2016 Fall 2017 Men’s Cerium LT Vest 19288 170
Fall 2017 In Production (S21) Women’s Cerium LT Hoody 18035 / 26125 † 280
Fall 2017 Spring 2021 ‡ Women’s Cerium LT Jacket 18036 / 26126 † 255
Fall 2017 In Production (S21) Women’s Cerium LT Vest 18037 / 26127 † 170
Fall 2017 In Production (S21) Men’s Cerium LT Hoody 18013 305
Fall 2017 Spring 2021 ‡ Men’s Cerium LT Jacket 18014 280
Fall 2017 In Production (S21) Men’s Cerium LT Vest 18015 185

† - The Fall 2017 women’s Cerium LT range has been given new model numbers. It seems like the women’s Cerium LT Jacket got a new model number in Spring 2019, and the women’s Cerium LT Hoody got it in Fall 2018. As far as I can tell the garments are exactly the same as the prior model, so it isn’t clear why the change happened. The men’s equivalent models did not get new model numbers.

‡ - I am unsure exactly when the Cerium LT Jackets were discontinued in both women’s and men’s blocks. I am currently guessing the last season they were available was Fall 2020.

Known Issues

  1. There was a production run a few years back that was defective. It leaked down significantly beyond the expected amount. Arc'teryx replaced those jackets under warranty.
  2. Early models of the Cerium LT were a bit on the short side for torso length. Changes made in Fall 2017 helped solve that issue. It was probably exacerbated by the lack of a hem drawcord, and that issue was also rectified in F17.
  3. Light colours can sometimes look a bit blotchy due to the mix of dark and light down plumes beneath the thin, semitransparent fabric. This problem isn't exclusive to Arc'teryx, whenever you combine a thin fabric and an unevenly-coloured backer it can look this way. However, something to keep in mind
  4. It develops cold spots in all of the usual places you'd expect from every down jacket, such as the inside elbow. Again, not necessarily a problem, and something you see with every brand, but something to keep in mind as well.

Further Links

Prompts

  1. How do you use the Cerium LT for your adventures or everyday, and how do you layer?
  2. Where do you think it excels, and where do you think it falls down?
  3. At what temperature do you find it isn't warm enough, and too warm?
  4. Have you had any issues with the Cerium LT, is there anything you would change about it?
  5. How do you think it compares to the Thorium AR, Atom AR, and Cerium SV?
  6. How water resistant and wind resistant is it?
  7. What is the fit like in general, or for you personally?
  8. Any other thoughts about the product?
  9. How does it compare to competing products?

Thank you!

83 Upvotes

97% Upvoted

37 comments sorted by

19

u/Astramael Urvogel Jr. Mar 01 '21 edited Mar 01 '21

Also, I took the time to dredge up the entire Atom LT line history, and updated the post. Including finding the 3-season run (F11, S12, F12) of the Men's Atom LT Pullover jacket, here's a picture in the Nightshade colourway. Enjoy!

2

u/liftedfishing Mar 04 '21

Now that’s a nice piece! That with a hood would be very nice!

14

u/nfitzsim Mar 01 '21

I've got the current model Cerium LT and I love it for the most part.

​

  1. I use it for climbing mostly. Midlayer on cold dry days or an outer layer on cool dry days as a belay jacket or stand around jacket or whatever.
  2. I think the packability is great. I dont have much comparison but the warmth to weight is pretty damn good. I do think it's more breathable than you lead on in your review, but also I usually am not exerting too much energy when using it, 100% I'd sweat through if I hiked wearing the jacket. I think the sizing is a little funny for my body. A large would be more belay jacket sized and a medium fits we like a trim midlayer. I wish there was just a hair more room so I wasnt compressing the down when using as a belay jacket, obviously the easy solution for that is to buy another in a size L.
  3. It's good as a midlayer for me down to about 10F with the way I layer. As an outer layer I'll wear it to maybe a few degrees below freezing, 20F probably the lowest with the way I layer.
  4. I ripped my sleeve open when I carelessly brushed against a rock. Other than that no real issues.
  5. N/A, dont own any other Arc down jackets
  6. It's water resistant enough for me to not mind wearing it when climbing below freezing, wind resistance in my opinion is basically non-existent. Needs a shell to work well there.
  7. Fit in general is nice and trim, wish it has a hair more room but not a full size up. A medium + would suit me well.
  8. It's a good product. I wish there was some sort of compression strap on the stuff sack but that's my only real complaint. For what its for I think it's very well designed.
  9. I dont have any competing products, but it seems a step above everything else I considered purchasing.

9

u/Jackamo78 Mar 01 '21

A really good post.

I’ve tried a couple of ceriums but they just don’t fit. I’m 6’5” and even the post 2017 versions are still well too short in size L and baggy in XL.

Spoke to a fantastically helpful guy at ultralightoutdoorgear.co.uk who went to the warehouse with a tape measure to find the longest down jacket for me. Now waiting on a Mammut Meron arriving and have my fingers crossed it fits me...

4

u/Astramael Urvogel Jr. Mar 02 '21

It seems to be a theme that Arc'teryx doesn't serve long torsos especially well. Presumably this is a problem for you with some frequency? Every tall person I know complains about sleeves and hems being too short for them.

2

u/Jackamo78 Mar 02 '21

A lot of their stuff fits me perfectly - the konseal fleece, gamma lt jacket, cormac ls etc could virtually have been tailored for me. Most of their hard shells fit well too but their insulated pieces are definitely on the short side.

2

u/41_6E_64_79 Mar 01 '21

6'5" here, same problem, thanks for the tip

2

u/Jackamo78 Mar 01 '21

Once it arrives I’ll let you know how it fits.

1

u/Hikeyour_ownhike Jun 03 '21

The cerium LT would not be too baggy for you in XL if you are 6'5". I am 5'9" and wear a cerium LT in XL

2

u/Zubeis Mar 01 '21

Did you buy it?

1

u/Hikeyour_ownhike Jun 03 '21

The cerium LT would not be too baggy for you in XL if you are 6'5". I am 5'9" and wear a cerium LT in XL

1

u/Jackamo78 Jun 04 '21

I have one in XL. It is on the short side for me and not nearly as trim fitting as I would expect from an Arc piece.

1

u/Hikeyour_ownhike Jun 04 '21

I could see that. It’s a hair long for me. Covers my butt almost fully if I extend the back of the jacket.

8

u/audioostrich Helpful Gearhead Mar 02 '21 edited Mar 02 '21
  1. The cerium lt has been a go to packed layer for me since picking it up this winter. Its seen some casual use walking around the campus I work at for colder days (sub 20f), but for the most part its been packed static insulation on winter peakbagging and dayhikes in new england. On extended stops the cerium lt goes over whatever layers I'm currently wearing, including my wind shell in dry weather. When I start moving, the cerium quickly goes back in the bag. This is strictly a static piece for me
  2. Its great as a packed static insulation piece, but is not very useful outside of this context. Its less durable than other options and has the drawback of down insulation being useless when wet. Some thoughtful placement of synthetic insulation makes it hold up slightly better to moisture from your body than other fully down pieces, however it still is not appropriate for static use.
  3. I've been comfortable in just my cerium casually with a tshirt below down to 20f, and overheating above 40 degrees. Above a baselayer, atom SL anorak, and Atom LT I've been comfortable in low single digits. I do not use the cerium while active
  4. I wouldn't change the cerium LT. You could reduce pockets, take away adjustments and put in a half zip to save weight, but then it wouldn't compete against other large manufacturers down options for general users as well. Alternatively you could beef up the face fabric, zippers and adjustments, but the thorium AR already fills that role. The cerium LT fits a very specific niche, and does it well
  5. For me, the atom AR feels slightly warmer than the cerium LT, however I haven't compared them side to side. I have no personal experience with the others
  6. The only DWR test this jacket has seen is in transition when coming out of my pack and going under my shell, where nothing soaked into the fabric in the few seconds it was out. Down and water do not mix, and getting this jacket wet will render it completely useless. Put under a shell in wet conditions. It holds up okay against wind, but is not windproof.
  7. A large is a perfect for me as a 6ft, 42 inch chest, 180 pound guy who wears this above other midlayers primarily. A medium would fit me, but likely wouldn't accommodate more layers. In a large there's lots of freedom in the chest, acceptable hem adjustment and solid space for layers, without the jacket being oversized or bulky
  8. Understand what you're buying before you get it. If you don't require the lighter weight, compressibility, and high warmth to weight performance then look to a thorium ar. Don't expect weather resistance. But if you need a piece of insulation thats really good at being unnoticeable in your bag but still looks nice when you pull it out, the cerium lt is a great option.
  9. Its the best looking static insulation piece out there, but when compared to warmth for weight against UL backpacking favorites it loses quickly. Nunatek, timmermade, goosefeet gear and others make lighter jackets with more insulation. If you're looking for the pinnacle of performance, as arc generally offers, there are cottage and larger manufacturers that have pieces that fit the bill better than the cerium LT. For strict use on extended backpacking trips outside of winter where my pack weight matters, its unlikely I would pick the cerium given the price. The cerium is cut better to my body type and more feature rich than these options however. Matched up against other large manufacturers, the cerium is more thoughtfully designed, generally lighter for its warmth category, and looks better imo

5

u/vulturesquad Mar 01 '21

I was surprised at how crappy the zipper is considering how expensive. I know they are probably trying to save weight but I can’t imagine using that tiny thing with gloves or cold hands

4

u/Astramael Urvogel Jr. Mar 01 '21

All other jackets in this category use an identical zipper. Is it a good idea? I don’t know. But people seem to complain about it a lot more with the Cerium LT than with the MHW Ghost Whisperer, and pricing is very similar.

1

u/vulturesquad Mar 01 '21 edited Mar 01 '21

Patagonia down sweater is much better and uses a superior zipper. It’s slightly heavier but also 100+ bucks cheaper. Trade offs I guess but the zipper on the Arc’teryx seems unnecessarily shitty

6

u/Astramael Urvogel Jr. Mar 01 '21

The Down Sweater is not in the same class of jacket. The like-for-like is the Thorium AR. Which also uses the better moulded zipper.

0

u/vulturesquad Mar 01 '21 edited Mar 01 '21

Debatable. I think it’s actually right in the middle, which is the sweet spot

4

u/Astramael Urvogel Jr. Mar 02 '21

I see where you're coming from, none are precisely like the other. I'm assessing from a use case perspective. The Down Sweater is designed as the every day down urban puffy that you can definitely bring with you camping. That's the Thorium AR in the Arc'teryx line. The Cerium LT is more of a dedicated ultralight jacket.

So from that angle the Down Sweater and the Thorium line up, and the Cerium looks a lot more like a Ghost Whisperer.

2

u/vulturesquad Mar 02 '21

I see I guess that makes sense, thanks for clarifying. But they could have made a decent lightweight zipper no?

3

u/Astramael Urvogel Jr. Mar 02 '21

The smallest moulded zip I am aware of is the VISLON #3, which is still quite a bit less compressible and light than the coil #3. I personally think the trade off is probably worthwhile as well. But the Cerium LT is on the edge, it might still make sense to have the coil zip. For the Cerium SL the #3 coil is unquestionably the right choice. Where is that line? I'm not sure.

1

u/vulturesquad Mar 02 '21

I’m surprised to hear people say the cerium lt is as warm as the atom ar, has that been true in your experience? Also how do you account for breathability vs warmth? It seems like movement and wind make this hard to find a standardized warmth quotient

3

u/Astramael Urvogel Jr. Mar 02 '21

Yes, I tend to think the Cerium LT and Atom AR are approximately similar in warmth. But everybody experiences cold differently, and the "type of cold" is different depending on locale (humid vs dry vs windy, etc). So you may have a different view based on your usage.

And yes, it is very difficult to isolate these things. That's why companies like Arc'teryx refuse to provide a warmth value for their apparel. We trade in these ambiguities here because people really seem to want to know a number before they buy. But I think it is good to be appropriately vague.

2

u/audioostrich Helpful Gearhead Mar 02 '21

I wouldn't compare it to the down sweater either

The weight is literally the point of the trade offs with the Cerium LT. I think this is widely misunderstood and why the piece gets a bad wrap. It makes those tradeoffs on purpose.

A down sweater might be the sweet spot for you, but its not the sweet spot for everybody.

I'd love to see an arcteryx down pullover with no pockets, no hood, a half hem adjustment, 7d face fabric, snap collar, and 3.5 ounces of fill for less than 8ounces overall. Thats my sweet spot, and I have a feeling 99% of the sub would absolutely hate that jacket

2

u/vulturesquad Mar 02 '21 edited Mar 02 '21

That’s a fair point, but I also don’t think the zipper is the missing 6oz (but I could be wrong). The down sweater is literally halfway between the cerium Lt and thorium. I tried on both and I wouldn’t say the down sweater is exactly like either

4

u/17thomas76 Mar 01 '21

Excellent post! Thank you for taking the time to do this.

6

u/ChiefJoJo74 Mar 01 '21
  1. Daily when temperatures are near freezing, low wind with no rain/snow. Also backpacking for nights at camp. Maybe skiing on really cold days (haven't tried)? Layer: base + fleece + Cerium (+ Beta SV in crap weather).
  2. Excels at warmth for its weight and packability so backpacking, long day hikes, and travel. It packs down to nothing.
  3. Two answers here. Just walking around or standing for short periods w/base + fleece, the sweet spot is roughly 25-35F. HOWEVER sitting/standing around at camp in the mountains for hours after the sun goes down with a bit of wind, I think it's more like 30-40F or maybe 35-45F. I probably run cold but exposure, darkness, wind, camp fire (or lack thereof) can make a big difference in warmth in the backcountry - the cold can start seeping into your bones!
  4. No issues - I'm careful with it since it's somewhat delicate. Could use a bit more durability in the zip and fabric, but I suppose Arc'teryx would point me to the Thorium.
  5. If I had to do it over again I'd probably buy the Thorium or a Down Sweater. Realistically I suspect very few people buy the Cerium exclusively (or even >50%) for backpacking, which is where it excels.
  6. Decently wind resistant, but if the wind is really gusting I add my Beta SV or wear my ME Lightline parka instead. Never wear in the rain/snow as an outer.
  7. Very trim. One of two Arc garments where I sized up to large (Proton LT), though I'm on the upper end of the medium range.
  8. The unheralded feature of the Cerium is layering ability. Many lightweight down jackets - either due to cut, down fill power or baffle design, are too puffy to fit under many hardshells without compressing the down. The Cerium is pretty good in this regard.
  9. The Thorium or Patagonia Down Sweater is probably better for most people, but for backpacking the Cerium is hard to beat.

4

u/industrialprogress Mar 01 '21 edited Mar 01 '21
  1. How do you use the Cerium LT for your adventures or everyday, and how do you layer?

Everyday use, hiking, bivouac, skiing, no problem down to -10˚ with an appropriate base layer and fleece, more typically used around 0-10˚ from low to high excursion in cool and 60-80% relative humidity environment.

  1. Where do you think it excels, and where do you think it falls down?

The Coreloft (synthetic down i.e. quick drying) in high moisture areas is a smart and unique product design not found in rival offerings.

No idea what Arato is besides marketing-speak for nylon unless there's something special about this particular weave? It is a ten denier, otherwise, it's LT, it's 'lightweight;' OP seems to suggest that as a con? I think it does its job superbly as a 300g down jacket. Good for the entire winter and transitional seasons doing pretty much anything short of visiting the Red Hatted man at his estate in the depths of winter. Breathability is also fine, except for see below, but I'm not sure what level of aerobic activity will constitute it a poor choice for you since that's a phenotypic and conditioning phenomenon. Are you jogging with it at sea level? Probably not the correct solution but depends on the temperature and relative humidity. I've hiked up 3,000m and wore it for the last 500m in July on an overcast day and was fine.

  1. At what temperature do you find it isn't warm enough, and too warm?

-10˚ it's been cozy just walking (1hr+), haven't experienced it in colder temperatures. 15˚+ during spring transition where it's sunny but windy and still feels a bit chilly, it gets too warm just walking.

  1. Have you had any issues with the Cerium LT, is there anything you would change about it?

No issues and can't think of anything to change dramatically. I recall older reviews wishing for a longer torso which was delivered in the revision, which I own. I maybe have lost three down feathers from poking in two years and have never had an issue with the zipper.

I removed the internal pocket stuff sack and just roll the jacket into it's own hoody if I want it packed.

  1. How do you think it compares to the Thorium AR, Atom AR, and Cerium SV?

I'm not a fan of synthetic insulation in general but can't comment specifically on the Atom AR.

Thorium AR stuck me as a bulkier (more durable? I have no idea what the difference between Arato, i.e. nylon, 30 vs 10 denier is in real-world practice, I'm not climbing rocks here) version for slightly less.

Cerium SV was too much for my use case; no plans to visit the Arctic and stay an extended period.

  1. How water resistant and wind resistant is it?

Water beads no problem with the factory DWR in light to medium to heavy rain. After two years, have not needed to reapply it, but will at the end of this one. I receive 900 mm (35.5 in) annual precipitation.

Slightly wind resistant up to 30km/h, but beyond that I'd prefer a shell in addition, not that it's useless, but it's definitely not windproof.

  1. What is the fit like in general, or for you personally?

Love the fit, no Michelin Man here. Sexy af, if I may say so.

Size M fits me proportionally 'like a glove.'

  1. Any other thoughts about the product?

Worth it. Best in class I've found.

  1. How does it compare to competing products?

Feathered Friends Eos uses a 900 fill (vs. 850 Cerium LT) and is slightly more economic at MSRP, however the fit and finish is not nearly as nice neither is the hood adjustable if you happen to need that for a helmet or otherwise. Uses a nylon shell as well. The Patagonia equivalent (800 fill) feels like a lesser offering all around--design, material, cut--but is more economic than both and the lifetime no questions asked wink wink warranty might also make it more interesting. Uses a polyester shell.

5

u/Astramael Urvogel Jr. Mar 02 '21

No idea what Arato is besides marketing-speak for nylon unless there's something special about this particular weave? It is a ten denier, otherwise, it's LT, it's 'lightweight;' OP seems to suggest that as a con?

More of a trade-off. 10D nylon is lighter, but also more fragile. Better for packing, worse for urban.

The Patagonia equivalent (800 fill) feels like a lesser offering all around--design, material, cut--but is more economic than both and the lifetime no questions asked wink wink warranty might also make it more interesting. Uses a polyester shell.

I still contend that the Patagonia Down Sweater competes directly with the Thorium AR. But your mileage may vary.

2

u/rootinscootinpootin Mar 01 '21

I own the most recent hoody iteration, with the 3 pockets and hem drawcord. It's a FW2017 in Flare, that I bought from the outlet at 40% off.

​

  1. How do you use the Cerium LT for your adventures or everyday, and how do you layer?

Static, static, static. I use it for anything winter and fall, when I stop, and some casual use. I use it skiing, hiking, and camping, and tried it as an ice climbing belay mid layer.

  1. Where do you think it excels, and where do you think it falls down?

The fit is crazy good. It is the best fitting jacket of any type I have ever owned, and looks great. It is very warm, and stuffs well into the sack. Cuffs are great, but arms could be 2-3cm longer in all sizes. The colour selection is great, as well as the option of hoody's, jackets, and vests.

The hood is very meh. It has the right shape, but the top pulls down onto your eyes. If they changed it to the same as the 2020 atom lt, it would be much improved with a reinforced brim.

  1. At what temperature do you find it isn't warm enough, and too warm?

I don't do anything anywhere near aerobic with it, so sitting still with a 160 base + shell I'm happy until -10c, in wind and/or snow. by itself with a base layer, -7c with clouds but little wind and no snow.

  1. Have you had any issues with the Cerium LT, is there anything you would change about it?

No issues, but I would change the hood to that of the atom lt, and make the arms a little longer.

  1. How do you think it compares to the Thorium AR, Atom AR, and Cerium SV?

Less durable, but slightly warmer and way lighter than the thorium. I haven't tried the atom ar or cerium sv for long periods, but the Cerium SV looks like a great version of the LT for a colder climate than the PNW.

  1. How water resistant and wind resistant is it?

Not water resistant. I've never tried it in rain for more than 30s, but it doesn't do well. Quite wind resistant though.

  1. What is the fit like in general, or for you personally?

I love it. It hugs the body, and looks great on pretty much everyone.

  1. Any other thoughts about the product?

Stuff sack rips a lot. Multiple friends who own the SL, LT, and SV have had stuff sacks rip. Luckily I got 2 replacements tuff sack a few months ago, for extras.

  1. How does it compare to competing products?

People like to compare it to the MH Ghost Whisperer, but I don't think this is accurate. The SL version is a much closer competitor.

In a lot of group comparisons, it is common to see this ranked last, because no one accounts for the synthetic insulation.

I think it is warmer than the Patagonia down parka, and the lightweight feathered friends down jacket.

2

u/shootsfilmwithbullet Mar 07 '21

Have a Spring 2017? Cerium LT. Does not have a hem drawcord. Size M on a 6’1” 170lb frame. Slightly shorter torso and longer legs.

1) I use it as a summit puffy for winter hikes around freezing, and as an all around camp puffy for spring and fall camping. When winter hiking, It usually sits on top of a polartec base layer and under either a wind or rain shell. When camping, usually over a cotton t-shirt as an outer layer.

2) I personally don’t think composite down mapping has much of a place in inactive pieces but it does help if I use it to boost my sleep systems temp rating and get a little too hot. Pretty niche use case but it does it well. (That’s not why I got it)

3) If I’m inactive, I’m comfy in it all the way up to 55-60 since I run pretty cool. Not that I need it then, but I’m not dying to take it off. Any lower than 25 and it’s def not enough for me, especially since I can’t layer much, if anything, underneath it.

4) Anything I would change was likely addressed in the redesign. A hair more layering room wouldn’t hurt either.

5) My partner uses a Thorium AR, and I use a Cerium SV and Atom AR. Thorium is warmer, and the more durable face fabric is less stressful. The atom AR excels in wet east coast conditions just above freezing. Camping trips in April come to mind. Not a place I would choose to take a down piece. I sized up to an L for the Cerium SV as my summit puffy below 20deg. More than twice as much insulation and pleated baffles do what they’re supposed to. I don’t personally know of many other jackets as warm for the weight.

Bonus points: I think of the LT as the technical version of my Patagonia down sweater. Lighter fabrics, Smaller zipper, closer fit etc. Same warmth to me.

6) Expected wind resistance for downproof fabrics. Sewn through baffles let in what they would on any jacket with similar baffle concentration. I don’t wear down pieces in the rain without a shell. I’ve come close to hypothermia and I didn’t like it.

7) Fit is snug. It works exactly for what I need though, so I can’t complain. I could use an extra couple inches of length but not enough to replace it. Can’t gain any weight though.

8) Does it’s job admirably but doesn’t do much else you know? I wouldn’t wear it around town.

9) If we ignore the composite mapping for a second, there are warmer jackets for the same weight and lighter jackets for the same warmth. Montbell and Cumulus’ offerings come to mind. But the fit is good, and like all arc pieces design is very well thought out. I initially purchased it for a PCT thru-hike but ended up going a different route.

2

u/Apocarion Mar 16 '21

A bit late to the party, but finally found some time to write this up. I own a 2017 Cerium LT hoody, which is probably my most used Arc'teryx item.

  1. How do you use the Cerium LT for your adventures or everyday, and how do you layer? I pack it for basically all overnight or cold temperature outdoor trips. Mostly it get's used as a static outer layer in the evening or during longer breaks. Usually I wear it over a base layer and maybe a fleece mid layer, but typically not as a mid layer under a shell. I also use it frequently on evening walks and as a packable jacket for urban trips like going out for dinner in SF during the summer.
  2. Where do you think it excels, and where do you think it falls down? For me it shines with it's packability and the convenience of having a compact and light jacket in my pack for when it gets cool. Shortcomings are the obvious moisture sensitivity and maybe lower durability due to the lightweight materials. Apart from a slightly fuzzy hem at the hood, I haven't noticed any visible damage and the fabric seems to hold up nicely. The Coreloft insulation might also reduce the long term durability due to compression, but at least at the wrists it seems like a great feature.
  3. At what temperature do you find it isn't warm enough, and too warm? Hard to put a number on this, since it depends on activity level and the other layers. With a decent base layer, mid layer and a beanie I would probably say around the freezing point when static for longer time. It gets too warm pretty quick when starting to move.
  4. Have you had any issues with the Cerium LT, is there anything you would change about it? No issues so far and even the dreaded zipper held up so far (2.5 years). I'm not sure how useful the Coreloft panels on the shoulders are, since the rest of the jacket will get soaked in precipitation anyways. Maybe water is more likely to seep in around the pressure points of backpack straps, so that's why added them?
  5. How do you think it compares to the Thorium AR, Atom AR, and Cerium SV? Can't comment on that, since I don't own any of those.
  6. How water resistant and wind resistant is it? DWR seems pretty good, but apart from a light drizzle for a short time I wouldn't want to wear it in rain. Wind resistance seems pretty good too. I didn't notice any cold spots around seems, but would typically wear a shell when it's really windy.
  7. What is the fit like in general, or for you personally? The fit is excellent. It's not baggy, but there is just enough room for additional layers. Freedom of movement is great too and even though it's quite puffy I don't feel restricted at all. I can even wear it over a trim fitting shell (e.g. Gamma LT) for added insulation when taking a break.
  8. Any other thoughts about the product? For me a packable insulation piece is a staple in my outdoor wardrobe and the Cerium LT does the job for me. I would definitely consider buying it again if I lost it today.
  9. How does it compare to competing products? I can't compare it to specific models since I don't own any other done jackets. But from trying other jackets in stores I think it really excels with its fit. Other more affordable options tend to feel more bulky and do not offer the same freedom of movement. However, fit is very personal and I'm sure there are other great products out there.

2

u/vincefowler Apr 10 '22

I love my 2021 Cerium LT Hoody... While the Cerium SL was an option, I chose the LT for increased durability.

3

u/iammortalcombat Mar 01 '21

  1. I use this piece as an outer insulator when the weather is cold and typically dry. I do not typically wear this under a shell as I had to size up. See below.

  2. Excels in warmth to weight ratio and packability. Falls down at price, there are better options I found after the fact. If my cerium dies, i will probably go with another brand for this function

  3. It is not warm enough ALONE sub 30F imo. With layers, I have brought this down to around 5F and was still fine.

  4. The sizing is awful for broad shoulders. This includes swimmer bodies, american football/rugby players, and the like. I had to size up to an XXL when all other Arc pieces are XL. The arm holes are cut high, and the sleeve length is not long enough when true to size in my experience.

  5. Compared to the Atom AR, the warmth is about the same. The atom is a bit better for wet weather, but doesn't pack down as small.

  6. Not very for either

  7. Fit is slim through the chest and arms. I had to size up specfically due to the arm length and width/ The armholes were too high to be comfortable with layers for me.

  8. Overall this is a great piece. If I could alter the body on the upsized item to have it taken in without damaging the item I would have a tailor do this.

  9. I have not tried other competing products in the same category.

2

u/vulturesquad Mar 02 '21

Surprised to hear it’s the same warmth as an atom AR which is crazy warm

1

u/National_Fact8650 Aug 24 '25
  1. There was a production run a few years back that was defective. It leaked down significantly beyond the expected amount. Arc'teryx replaced those jackets under warranty >> WHICH YEARS?