Customer Reviews Arc'teryx Nuclei Pants

I don't know how I survived 5 years of vanlife and winter climbing without puffy pants! These are an absolute game changer when it comes to weathering cold days out climbing or adventuring. From pulling on in the frosty morning while making coffee to wearing between burns on a project, these pants will keep you toasty warm. The reinforced knees and backside improve durability as well. For sizing reference, I wear a 2 or 4 in most Arc pants and ordered a size Small in the Nuclei puffies. This is big enough for me to pull on over a base layer and harness.

Great pant. Have used down in to the teens Fahrenheit. The front "half" of the waist if you think side zipper to side zipper, again in the front, is adjustable. This is a great design and perhaps the only solution to adjustability with full side zips. If you plan to have more than close fitting clothing I think sizing up would be ok . Say over bulkier hiking pants, for example. Weight is pretty amazing for product being synthetic and warmth. Knees and seat material are nice and more robust where needed.

It's about time I started packing extra insulating layers for my legs! We're great at bringing spare upper body layers, but the pants have been something I have neglected. Now that I have these Proton Pants, I am more prepared, and more comfortable. The full length zippers make it next to effortless to put on or take off, even with crampons or ski boots.

Saving myself always when it gets nasty on the mountain.

These are awesome, very warm insulated pants. I've never been cold enough that I needed them doing an activity but I've taken them on expeditions to the Himalaya, Waddington, and Canadian Rockies where they've been critical in camp and at night. Full zip makes them easy on/off and sizing seems normal.

These pants are very warm for the weight. There is reinforcement in high wear areas to give extra durability while still being packable. The fact they can pack into their own pocket (with a carabiner loop) is a huge space saver in your pack. The zipper works great when you are putting them on while wearing crampons. Much easier than other brands I have tried. The only con is the fact they only zip up from the bottom but it is a sacrifice I am willing to make. Maybe the next generation will include this and they will be perfect. These pants literally saved my behind when I was climbing in -25F (-30C) and starting my decent. My legs were getting cold and started losing sensation in my hips. As soon as I put these on, my legs were toasty warm. IMHO these are the best value for fit, warmth, weight, packability, and durability out there. I wear a large and large fit perfectly over my other layers.

As a paraplegic I use these pants daily for commuting to and from work on my Bowhead bike year round. They are compact enough to keep on under shell pants for the entire work day keeping you toasty for the ride home.

I am happy with this very light and warm pant, especially for protection purposes, cold and windy conditions

Got these pants for winter steelheading, snowshoeing and skiing. Awesome pant so far, been keeping me super warm on cold days. My only recommendation for V2 would be to have a snap or clip around the waist, I find when layering they can bit a bit tight around my legs putting them on.

Bought as a winter belay pant for rock and ice, ski traverse camping. I made sure to purchase a size larger to fit over a harness, warm pants to belay with so far.

Used these on a winter backpack, very warm and comfortable Side zippers work great. I kind of wonder if something similar but with active (breathable) insulation would be even better, but these are so easy to add or remove while moving that this is not a problem.

I am continually amazed by how warm and light Arcteryx products are. Did not think they would be but they are very warm. Almost hot. Stretchy in the right spots, great zipper locations, extra durable for how light they are. They fit large for sure.

I was initially sceptical about this pant when I compared it to the Atom LT, because I thought it was going to be much heavier. I was wrong! It is much warmer, just as packable, and more durable than its predecessor at hardly any extra weight. A long inseam keeps your feet and ankles warm, while still being able to wear it high over your harness. Full length and easy to use zips make for easy donning at belays. Full length zips are KEY!! Make sure you buy a larger waist size if you plan on wearing it over a harness.

When you are about to bail because it gets cold and windy this pant changes the game. Cant imagine big alpine climbs without them.

Bought these pants a while back. Very light and warm. I'm typically a 32in waist with a 34in inseam. Went with the medium size. Length is very good, almost goes down past the ankles. Waist is a little big but the draw seam helps out some. Nice shiny material on the outside with reinforced butt and knees. Full side zips and one large pocket is a nice feature. Should be great for XC ski or to wear under some shell pants!

Love these! Been looking for a synthetic insulated pant for a long time. Coupled with GTX seat and knees these pants are bomb for late season!

I bought them to wear on cold days and so far they perform as planned, warm and comfy. I however would have like them to have either a "silicon non slip"-strip on the inside of the hem or suspenders, since the pants tend to slip down, especially if you are wearing fleece or other shell pants underneath.

Great Arcteryx quality! Extremely warm and lightweight- perfect for ice climbing. I'm normally a small but needed a medium to fit over winter kit, harness etc. Would give 5 stars if fly was fully separating to five full access to tie in area and, if side zips were perhaps two way. ( really deserves 5 stars though and these are just thoughtful suggestions)

More of a first impression review. I am 5'7, 150 lbs. Usually order smalls, 29 - 30" waist and short inseams. I ordered a S and XS to try on. These seem kinda long, which is expected as they are not short inseam. With the S, cuffs drag on the ground. XS does not, but then the seat was too tight and started was gooch restrictive. Went with S. Tightening the drawcords at the cuff helps shorten them up, and of course you wouldn't be wearing these without boots anyways. But still, it would be nice to have a short inseam. Short people problems. Other things: Stuff sack pocket could be larger. You really have to stuff them in. Haven't actually stuffed them in AND closed the zipper yet. Im sure the Coreloft can handle it, but it feels like you're pulverizing the poor insulation. Zipper tab will be at bottom when it is done up, not top. Fly does not come through waistband as it is continuous. The latter two points are neither pros or cons - they just are. They fit underneath my shell pants (albeit snugly), should I feel the need to go against the intended use and turn this outer layer into a mid-layer. Excited to finally have fancy shmancy lightweight puffy pants. Bring on the cold. I hope my crampons don't acquire a taste for Arato 15 face fabric.

I love the Nuclei FL hoody (other the the hood), so I bought the Nuclei pants as well. It is also light as air and the fabric feels exactly the same. It feels very warm for its weight. Love the look of it. Unfortunately- I think the biggest flaw is the sizing runs about an inch smaller than advertised. It's supposed to be 32 inches but you have to really stretch it. I compared it to my small Gamma LT - it's noticeably smaller. As a belay pants, you would expect it to be a bit bigger (so you can wear it over your pants). But it's the opposite - it's like the waist size of the RHO pants - which are tights! anyways, I will likely return this. But I like the pants too much - maybe I'll have to lose some weight.

5/5 as a product: durable, warm, love the full zippers for use with crampons. Minus 2 stars b/c only available in men's. Tight hips, baggy crotch worn by a woman. What if the Alpha jacket was only made in women's? Ha, would never happen. Arcteryx, you usually do better, let's keep that standard going.

I wanted an insulated, full zip pant for layering in backcountry and for belaying. First - there are no Womens options so had to order mens (sizing and hip differences matter). When on the XS fit well in length, a little odd to be so high waisted and tight at my small waist - but literally could NOT pull them on unzipped past my knees therefore had to unzip to put on. It was strange and frustrating and confusing..makes no sense for a pant that should be functional. Secondly - the zipper is only one way. So you have to unzip all the way UP to undo. To close you start at top and zip down. So you're not getting in to your lower layers or gear unless you bend over and unzip from bottom up! WHAT!? Did the designer ever wear layers or gear or ever have to pee in the woods? This makes no functional sense and compared to every other brand (MH Compressor, BD Belay Pant, and RAB Photon) who ALL have two-way zippers - Arcteryx failed miserably! Why not have the zippers be two way zip from the top to put on and access inside/adjust/pull down if you choose? Material and compressibility is about the only positive of these pants. I won't even bother ordering a SM to see if it fits a little better - without the two way zipper these pants are a disappointing fail. I expect better from Arc'teryx. I almost exclusively wear Arc'teryx - however the future in their styles/designs and true functionality is being compromised, hence losing brand trust and reliability.