Zpacks sleeping bags

"How does the bag due when you want to sleep on your side?"

You'll still try to keep the zipper underneath you. The zipper is so tiny I don't feel it on my hips if that's why you're asking. I have a short/regular and it's pretty snug but worth the weight loss from my traditional over 2 lb. mummy bag (rei sub kilo) at about 15 oz for a 20o bag. My buddy has one too and I just want to mention that if you see an older bag and a new bag you can tell how much better the stitching has gotten. I just got mine and it looks like something a large company would sell.

One thing someone mentioned is a good idea, asking for no zipper. I wish I'd thought of that, it probably only needs to be half as long as they make it and I think it would keep the bag warmer.

Rusty, instead of wondering about the loft claims take a look at how much down is being used in the bag/quilt. The amount (and quality) of down is the first thing I look at when I'm evalutating warmth, and then I also consider how spread out the down is (ie. a quilt needs a bit less down than a bag to be just as warm because there's no down under you). For quilts, I consider about 7oz to be 40F, 9.5oz to be 30F and 12oz to be 20F (assuming 800-900fp). For a bag you'd need a couple more ounces to get similar warmths.

Thanks, Dan. I would agree to that…if the bags were very close in size and design. The WM Ultralite and Zpack bags are completely different though. The Ultralite has a collar, full zipper, draft tube, hood and appears to be sized differently. I could guess as to what all that might weigh….but it would be just that, a guess.

Definitely +1 with Dan–what matters is the quality of down, and the weight of down per square inch of exposed, heat-radiating bag/quilt surface. I'd love to see a study of how warmth for a given down density/square inch of bag surface varies with allowed loft, but my guess, based on experience and remarks in other forums, is that maximizing loft for a given amount of down is a mixed bag (sorry)–near the densities of a typical sleeping bag, allowing greater loft for a given amount of down may not gain that much, and, if too much loft is allowed, may be counterproductive.

A very lofty bag looks great in a store, but if the baffle heights of a given bag were reduced from 2.5" to 2.25", (saving weight because of the reduced baffle material and the smaller outer layer surface area), and the total amount of down was the same, I doubt if the bag's warmth would change. More important is having a consistent density of down, IMHO–no feathery bits to create effective voids, or understuffed tubes, and with down quality and bag construction such that down is easily able to move around to achieve even density distribution, etc.

Having owned a WM Ultralite, it's a completely different bag–larger, hence more radiating surface, and with greater internal volume. (And, it takes up more room in the pack). For some, this will translate into more comfort, less compression; it is a very, very well made traditional bag. One could even argue that the level of craft in the Ultralite is higher–straighter seams, etc. But IMHO the down in Joe's bag is of a usefully higher quality, and personally, prefer the snugger fit.

Single side loft of Joe's 20 degree bag, between baffles, seems to be around 3".

Unzipping a side-zip bag when the temperature rises is less effective, (because the opening still remains sort of closed), than spreading the whole bag out, as the bottom zipper allows one to more easily do, without the hassle of dealing with a sideways hood, etc. So Joe's bag will have a large useful temperature range.

Has anyone been able to take pictures of their bag? Specifically with it zipped up around them

Im on the fence about the zipper and i'd love to see some user pictures to help me decide.

Thanks
Tyler

Thanks, James.

Since you had an Ultralite, I'd love to hear your thoughts on how the Zpacks bag compares after you get some time in it. Of course, I probably would not get the 2 oz overfill as you did. Would still like to hear your opinions though….or those of anyone else who has direct experience between the 20 deg Zpack and Western Mountaineering Ultralite.

And I agree with the other posters wanting to see some photos of someone in their Zpack bag. Lets see'um!! :)

I third the notion to see some photos from customers who recently purchased these.

Just got my bag today! Arrived much sooner than anticipated. Joe is awesome. Quality appears excellent. The actual measured total bag height between baffles appears to be about 6 to 6.5 inches, perhaps even a bit higher. I got some pics I will upload them soon.

Also, I got the version that has a side zip and draft tube. The side zip and draft tube were worth the 1 oz to me because I tend to roll around and sleep on my side, so a bottom zip would not suit me well! It is a snug fit, I would consider the foot box as small compared to all of my other bags. I do have a small amount of room at the shoulders, and there is no room to really "sprawl out" your arms, however I do not feel constricted at all, even on my side (I have pretty broad shoulders for my height and am using his regular width bag). It feels very comfortable to me, and is definitely very functional and efficiently designed. Since it is a 20 degree bag, I will be using it as a quilt most of the time anyways. Is very comfortable when opened completely and fits perfectly in "quilt mode" even with the side zip.

Jacob

Thanks to everyone for all the info.
I got mine in the mail about a week ago. I went w/ the 20 degree one and had Joe add 2 extra oz. of down. I'm just waiting to finish finals and
I'll take it to see how it does in the field. Pics. to be posted.

I am 6 feet, 190 pounds, 43"chest, restless side sleeper, some back! After reading all the above, went w/20 degree bag, straps( no zipper) large, wide w/2 ounces of overfill! Looks like about 21.5-22 ounces. Plan to use for 75 mile section hike on JMT next Sept.Just ordered from Joe!

you read or hear x" loft, but that doesnt tell the whole story.

A quilt very well may be consistent loft throughout. So may some bags.But not all bags.

I know my WM megalite has significantly more in the upper body and foot regions, and less in the middle. You can even see that looking at stock photos. the Summerlite looks similar.

If I bend it in half, double, where the foot region lays on top of the the head region, the combined loft in head/foot is about 14", so those areas have ~7" loft each, not the measly 4" you read about.

The middle of the bag has the least

And this is a 30 degree bag, not 20.

Hi Guys,

I have just put up a quick review here:

http://hiking26.blogspot.com.au/

In summary, a sweet sleeping bag, though takes a tiny bit to get used to.

Cheers,

Jeremy.

Jeremy
Nice initial review..wonder how you will fare in colder temps.

I'm still on the fence on a bag like this – I dont want a quilt and am contemplating this vs a custom hooded bag….

Having said that I think a few mods that i discussed with Joe could help you out:
1) neck draft collar – Joe said should be about 0.8oz for a nice 3" diameter baffle(and maybe less in 0.33 cuben
2) add velcro behind the neck so you can close the neck and cinch without closing the zip – i think this will totally solve your issue and can prob be done easily as a retrofit
3) I would add 4 pairs of loops for shockcord : one pair behind the neck near the velcro and 3 spaced evenly – this way you can have your cake and eat it too – get a shockcorded quilt if you want or zip up (you can always NOT take the shockcord
The purpose of the loop near the velcro is that i have found if you try to layer a quilt OVER a hooded bag (i do that with a light bag inside and i prefer a hooded one since you get the continuous draft protection around neck…which is great if T<20F) you cant really close behind the neck that easily since it really crushes the hood area of the inner bag – so i just put a short shockcord (i use it with an MLD XP quilt)
4) I also think the amount of down in these bags is below whats needed for the temp ratings so i would add 2 oz at least

Mike

Hi Michael,

Those mods sounds great. If/ when you get the quilt, I would love to see some pics to decide whether to add them. Also, I agree that overfill is a good idea, I got 2oz for safe keeping.

Also, I am going to add a video review of the bag in a couple of weeks to to give a better idea of dimensions etc.

Cheers,

Jeremy.

I recently picked up a Zpacks sleeping bag from the Gear Swap forum and had a chance to use it for 4 nights so I thought I'd post a little review here since there still doesn't seem to be much info out on these bags yet. My bag is a medium length, medium height 30 degree bag with 1 oz overfill and a side zip with a draft collar. It comes out right around the specified 15.3 oz without the dry bag.

A few details which people may ask: I slept on an XS Thermarest Prolite with a small cut up Ridgerest for my feet and lower legs. My shelter was a Big Agnes Fly Creek UL2. 1st night I left the fly off, all other nights I had the fly on. I always wore thick wool socks, merino wool briefs, a Cap 1 SW long-sleeve baselayer, and a fleece beanie. For extra warmth, I had two hoodless down jackets: a Montbell Half-Sleeve and a Stoic Hadron Cardigan. In general, I'd say I sleep about 5 degrees colder than most.

1st night: Started off by using the bag as quilt. I just had it draped on top of me until a stiff wind came by – the bag is so light the upper part of it levitated above me for a couple of seconds. After this, I crawled in and zipped up the bag. Later in the night, around 2 am, I felt chilled so I cinched up the neck collar. Then around 4 am I felt chilled again and put on my Montbell jacket. This kept me fine through the night. When I awoke, I was surprised to see frost all along the outside of my tent. One of the guys I was camping with said it sprinkled briefly for a couple minutes that night which would explain the small drops I saw on the outside of bag. Since we were car-camping at the trailhead and planned on heading out at dawn, I checked the temperature in my car: 32 degrees. One consequence of living in Arizona is that the temperature drops drastically at night, some times by as much as 40 or 50 degrees from the day-time high.

2nd night: Although the day-time high had been at least in the 70s, it was already in the mid 30s when I went to bed around 10pm. I knew it would be a cold night. After going through the usual stages of adding layers, zipping up, cinching up, etc, I woke up in the morning wearing both my down jackets. I wasn't cold but I wasn't toasty either. I don't know what the temperature was, but my water bottles were slushy when I woke up in the morning.

3rd night: This was the coldest night of them all. I hydrated myself well and ate a ton of food before going to bed in attempt to keep myself warmer throughout the night. I knew it would be a rough night after I put on my 2nd down jacket around 2 am. I woke up shivering around 4 am, so I did some in-tent aerobics and crunches and went back to sleep. This actually helped a lot as I was okay until morning. When I woke up, one water bottle was frozen solid and the other was very slushy.

4th night: I stayed plenty warm. We camped in a much warmer spot. The temperature probably only reached down into the mid-low 30s.

We were only expecting lows in the low 40s for this trip, so these cold temperatures were quite a surprise! As it turns out, a cold front happened to move in right as we left. Additionally, we spent our 2nd and 3rd night in a deep valley which got little sunlight and which all the cold air in the mountain range must have settled into at night. I certainly learned my lesson about selecting warm campsites. I typically camped on lots of forest duff, so at least it never felt like I was losing much heat from the ground.

All in all, I'm fairly pleased with the bag. I'm 5'6'', 160 lbs and find the girth and height to be perfect. When the temps drop, I really appreciate a trim bag. If I was a couple inches taller though, I think the bag would be too short for me. For the warmth, the bag is ridiculously light, especially when you consider that it has a long, easy-to-use zipper with a draft collar. Looking at the bag's loft in my house, I measure between 3.5 and 4.5 inches of double-layer loft. After this trip, I purchased a Melanzana fleece hoodie to sleep in as I don't think my Cap 1 baselayer provides enough warmth for its weight.

My only concern is the 900 fill power down in the bag. When I was in the field and things were damp, it seemed that the bag was slightly under-filled. Now that I'm at home, it seems to have plenty of fill. It's probably just my imagination, but this is what it seems like. I do think the extra 1 oz overfill was a good idea – I would actually recommend more. Since I can only think of a couple of cottage companies that still offer 800 fill power options, I guess the 900 fill power stuff must work fine. That being said, I would love to see a lower fill power option (to make the bag cheaper) and a synthetic option. I used to own a GoLite Ultra 20 quilt but always had drafts when I turned. The Zpacks bag is lighter, just as warm, and eliminates drafts for me.

One final thing: I wish the side zip was a split-zipper. My legs always felt quite warm and I wanted a way to ventilate them without ventilating my torso as well. I think this is something I may be able to add myself though.