Mammut Alyeska Bib

Versatility

These are lightweight bibs, which is definitely my preferred cut.

In mid-winter, I typically run Mons Royale merino boxers, long johns and bibs with two or three merino layers on my torso. All seams and zippers (see “pockets”) are extremely well sealed, so there was no wind penetration. I never felt cold in these pants, and found that on colder days (-15 F) I was comfortable.

When touring, I found that the bibs were very versatile without a jacket, since they fit like a ½ vest on top, keeping warmth in when starting or transitioning. While skinning, they can be comfortably folded down over the waist, or the chest can be zipped open for additional ventilation, which definitely aided in their versatility.

I did have an experience in Alaska on a river crossing where I was envious of my compadre’s full zip pants, since he was able to shed the layer prior to our mid-thigh barefoot river crossing, where mine only had a hip to knee side vent. This made me realize that although this bib is very technical and performance oriented, it is not as versatile as a traditional full zip mountaineering pant. Mammut does sell such pants, if you’re after full zips.

Cuffs (and Durability)

The cuffs of these pants are awesome. The multiple button system on the outside and inside is the best I’ve seen to adjust the size of the cuff when in crampons, walking the streets, or in your sneakers pre or post riding.

There is no extra material and very little added weight given the number of options that allow you to adjust the size of the cuff. And the buttons work; everything stays in place. (In contrast, the Burton [ak] cuff solution I tested this year wouldn’t stay in place, making it absolutely useless.)

I nominate Mammut for an A+ for actually extending the life of the most abused and underrated aspect of ski/snow pants, the cuff. They feature ‘tearproof Dyneema® edge protection’ and are are heavily re-inforced, yet they’re still lightweight and waterproof. With 25 days in these pants, I have no signs of cuff wear and tear, which is rare for me.

Weight

The Alyeska Bibs come in around 860 grams, a great weight given their durability and performance. When wearing them, I hardly notice the weight. When packing up for a trip, these can fit in a carry-on if required, and take little space in any bag. I believe they are some of the lightest pants I’ve worn.

Pockets

Mammut has really nailed the pockets in these pants. There are only three—two chest pockets and one on the thigh. This means you’ve got less room to pack a bunch of stuff that you don’t really need. All of the Alyeska’s pockets serve a purpose, and allow for beacon/device separation if you follow that protocol.

When worn with the Mammut Aleyaska jacket, there is a two way zip that allows for internal access from the right chest pocket of the jacket. This is handy to keep the weight of the beacon/camera/radio closer to your body while also keeping its batteries warm.

The thigh pocket is deep and large enough for beefier items such as a thick wallet, beacon, or snacks.

Zippers

The chest pockets have wide-tooth zippers, and the left pocket has a double zipper. The 18-inch chest zip goes both ways and offers a wind flap with buttons to ensure wind blocking. The one thigh pocket features a splashproof wide tooth zip with a rubber backing.

The thigh ventilation features thinner zips that are fully rubber and waterproof.

I had no durability issues with any of the zippers, and due to the simple construction of the pant, I see very few places for potential weakness.

Bottom Line

Pay attention to sizing. If you’re looking for a freeride fit, go up before you go down.

If I had done that, I could happily wear the Alyeska Bib for the next three seasons, and get a solid return on a $600 investment. These are top-of-the-line bibs, and if you are spending 50+ days in bibs each winter, you want something that is going to (a) last a few years, (b) be as comfortable, warm, and dry as possible, and (c) look pretty dope, too.

These bibs pull all of that off, and if you are into getting a bit more technical—touring/climbing/ etc—they are going to support you in your efforts.