Black Diamond  Coefficient LT One Piece Base Layer - Men's

The zip to get in is a bit short. So getting in isn’t so hard. But getting out is harder than it should be. Wear any paper thin wool baselayer under it and the extra friction really slows down taking it off. Prob just a matter of time before I’m pulling the sleeve to slide it off my paltry old man shoulders and will tear the sleeve off. And the flap… oh god. I sometimes wear this snow biking. Always in the dark, chilly Colorado nights. The entirety of the winter world likes to sweep in under the tail of nearly all my jackets/coats and sweep across the thin layers left exposed by this too short flap. I pull this thing on w/ high hopes. And each time wish it was better.

It’s warm and breathes quite well. I particularly like the hoody which fits quite well under my ski helmet and it’s out of the way when not in use. The reason for the 3 star rating is the length of the material on the back. In my opinion, it should be a bit longer such that it overlaps the bottoms. As is, when I bend or kneel to assist (ski patrol), the top pulls up leaving my lower back exposed. If I was to do it over, I would buy separate top and bottoms.

Enjoyed the head to ankle warmth that it provided while i was out on the mountain. Low profile with solid maneuverability, i even forgot i was wearing a adult onesie the whole time. The one downfall i do have is my lower back felt exposed to the cold due to the butt flap or back of the shirt not being long enough to be tucked. Small complaint but definitely worth every penny i spent.

I want to like this suit, but there are a couple of issues that I am struggling to get past. I'll start with the positives. This suit is just right in the warmth category. I use it regularly for ski patrol days in SW Montana, and it is comfortable and warm. The thickness is perfect on my legs and I add a thin long sleeve upper layer to keep me feeling just right. Huge success by BD. On the downside, the sizing is wonky for me. I'm 6'3" tall, athletic build 200 +/- lbs. I ordered the XL because being tight in the crotch was a no-go for me. In doing so, the elastic waste band is way too big and the tail of the shirt is way too short. Unfortunately this combination negates the benefits of the one piece suit. You can see what I reference in the stock photos of the model online. I didn't notice it when I was shopping for this piece of clothing, but it catches my attention now. I would like to try a large, but my height and the size chart suggest otherwise.

I was hoping for a hooded onsy to eliminate a baklava. Didn't provide very could neck and face shield. Had to wear an under shirt to reduce cold air rushing into the back flap. Had I been wearing pants instead of a bib, it would have been perfect access for snow down the back side. It's comfy but not what I was hoping it would be.

The material is comfortable, and it keeps me warm during outdoor activities. The fit is great, and it stretches well with movement, making it ideal for layering. For my use, I would have preferred a design without the opening in the back. Otherwise, it’s a solid, high-quality baselayer that performs well in the cold.

Fantastic overall - one of the first baselayers that I’ve found to actually do its job well. IMO, drying fast is the #1 priority for a piece like this, and it does a great job. On a multi-day splitboard trip it keeps me warm, and by the time I set up camp, it was always dry. Pros: 1. Truly feels like a second skin 2. Good amount of warmth 3. Dried very quickly 4. Zippers are very smooth Cons: 1. Back flap - like others have said I wish this was just a few inches longer! It was never an issue, but it was mildly annoying. High waisted pants or bibs solve the issue entirely, but not a perfect design on the length. 2. Chaffing - I’m used to wearing merino baselayers and this feels very soft as well HOWEVER the grid-type fleece definitely gave some nipple chafing with no shirt under. Not a crisis, but not ideal. 3. Getting it off - it’s easy to get on, but I feel like I’m trying to get out of a wetsuit when I’m taking it off! Overall 4/5 - does its job fantastically, but with a few small annoyances.

Eliminate the butt flap opening and make an actual one piece base layer. The material is awesome and the hood and everything fit great but it just leaves this big awkward hole behind your back. I really want to wear this thing but I can't.

Great layer, very warm, and the Buttflap functions great. Perfect layer for skiing or under a drysuit

I'll start with the bad and then follow up with the good. The point of a one piece for me is to eliminate fabric bunching around my waist in my layering system and to enable better breathing and to prevent shifting/riding from my pack's waist belt. I rarely drop a deuce in the field and stay pretty regular, so wearing bibs isn't really a problem for me. I ski in them on all resort days and don't have a drop seat. By including the rear drop seat it pretty much negates the point of the one piece and the overlap isn't enough so even with the sticky band fabric riding rode up on my waist belt exposing skin on my tour. I'd rather just remove the top part to make a brown and exclude the drop seat. I also don't like the hood or pocket. The hood bunches around my neck and makes dumping heat and breathing more difficult on the skin track. If I want a hood I will use my shell or use a hat or buff. If I am touring in my base layer I won't be needing a hat. The legs are way too long. I always wear high socks in the winter and wear 3/4 length base layers to prevent fabric building up, which inhibits breathability and can be uncomfortable on my calf. So I will have this piece hemmed. For what this is designed for it should be 3/4 length, like the Solution Bottoms, which sold out last year. Now for the good. The fabric is outstanding. I usually wear Powerstrech fleece as a baselayer on resort days and Solution Merino on touring days and warmer resort days. This is my first experience with Powergrid, I love it, and see it replacing powerstrech as a base layer. It breaths and wicks way better than power stretch and is almost as warm. The chest pocket is nice and big, so if you are into chest pockets they did a good job there, however as stated above I never use them and disagree with their inclusion on base layers. The zippers are high quality with have nice zipper pulls. The chin is protected with fabric to prevent chaffing. The overall build quality is great. This is a step in the right direction, as I think going to a one piece base layer is where I want to be. Hopefully BD sells enough of these to do another production run and when they do I hope they ask me for design input.