BPL Community:
I have developed a new way to attach a quilt to a mattress, in an effort to solve some of the issues with using quilts while capitalizing on the advantages. I’d like to hear the community’s initial thoughts and critiques.
*disclosure note: this is a commercial project, patents are pending, I am the inventor, the brand is ZENBIVY. Since it is not for sale, I believe I am posting in the correct location….
*note 2: The design goal of the product shown in the examples was to “combine the warmth and weight of a mummy bag with the comfort of your bed at home, so you have a single solution that can be used for summertime through full 3 season use, while being light enough for backpacking and comfortable enough for car camping” As such, the product shown weighs the same as a comparably spec’d mummy bag of the same EN rating (specs at the very end of the post).
As most folks here already know, a quilt is extremely comfortable because it already sleeps like a bed at home. Specifically, it allows the user to control the interior girth of the bag to regulate temperature just like you do at home. Just like you do naturally in your bed at home at night, when you are cold you wrap the covers tightly around you, and as you warm up you can expand naturally. It also has “covers” that mimic those at home, and it eliminates the restriction associated with mummy bags (pinned inside) and system bags (pinned to the mattress).
But as you are all aware, the quilt has two big problems that keep it from being a total solution for most people, both of which the new design attempts to solve:
1. insulating the head
2. quilt falls off the mattress
It would seem simple so solve the quilt falling off the mattress problem: just attach the two. But doing that creates two huge problems:
1. You lose the adjustable girth. If you attach the quilt to the edge of the pad, it creates too large an interior (if its big enough to roll around in), and two “cold spots” which are worst when you are on your side. (note: Katabatic Gear has largely solved this for ultra-lighters with their string-based system, also patented or patent pending I believe)
2. You are adding constriction by pinning the user to the mattress. (note: my last attempt at this, the Sierra Designs Backcountry Bed, provided adjustable girth (and head insulation), but suffered badly from the “pinning” phenomenon (and was ultimately not able to match the mummy in terms of weight and thermal efficiency).
Zenbivy’s solution is to attach the TOP of the quilt to the mattress with “hinges”. These hinges allow un-restriced girth adjustment (unlike Katabatic) AND they allow the quilt to “float”, eliminating pinning. This terrible sketch (sorry) compares our bed to mummies and a system bag that attaches the quilt to the pad:
The hinges allow unrestricted movement of the quilt UNTIL the point just before the quilt falls off the pad, and then they “engage”, so there is no way to “un-tuck” the quilt while it is attached. So you get full, unrestricted movement until you are about to lose the thermal seal, then it “catches”.
One really cool thing about using the hinges, is that they ALSO help solve the head insulation issue, because the hinges are attached to a hood, which is also separate from the quilt and attached to the mattress. When “tucked in” (zipped up), the quilt is forced into the hood and creates a fully enclosed and sealed head/neck area.
***quick note for ultra lighters: as you look at the following photos, you will quickly see that opportunities to reduce weight abound, especially when you start thinking about the pad and that bag as a single “thing”, vs. the bag/mattress mindset we have been in historically.
Unlike any bag on the market that I know of (please tell me if you can think of another), this bag as two parts, in addition to the mattress. (note: before you hammer me, I realize the model in the image is undersized. She is 5’4″ I believe, and this is the big quilt that fits to 6’6″ AND a “large” 25 x 77 mattress. It was the bag I had for the shoot, and the model I had, and is not intended to deceive).
You can see we covered the mattress with a sheet entirely (big weight investment) to solve the problem of sleeping directly on the cold, slick mattress.
This image shows how it “tucks in”, and shows how the “hinges” and the “hood” are connected into a single piece (called the yolk), and how it all zips together. Note that hoods are generally thought of as being there for your head, but this one is super-large and allows full access to the entire mattress, and is as much for your arms as your head.
This image shows how the quilt “floats” unrestricted on the “hinges”:
These images show how you would “tuck in” to sleep on a cold night. There are no draw cords or constructions. You just tuck the quilt into the hood. It stays there because of the way the quilt is attached to the hinges forces the quilt inside. You just roll to a comfortable spot, and adjust the “covers” like you would in your bed at home. The quilt fills the hood area naturally.
Clearly, one advantage of this system, especially for those who read these forums, is that you can use the quilt on its own, just like any other quilt. And since the “sheets” and “comforters” are separate, they can be mixed and matched (they use YKK MUSI zippers that are intended for inter-changeability). What other advantages can you see?
One big disadvantage is the reliance on a proper sized pad for your “sheet”. What other disadvantages can you see?
I’d love to hear comments on the system in general. AND I’d love to hear your thoughts about where something like this could go, especially from the “ultra-light” perspective. As always, I appreciate your insights….
***Final note, since I said it weighs “the same” as a mummy bag and I know I will be asked, the sample shown is a M/L quilt (fits to 6’6″) and uses a sheet that fits a “large” 25 x77 mattress. It has an anticipated EN rating of 25 degrees, 650 fill power down, a 30d shell and a 50d liner/sheet. As shown it weighs 2 pounds,7 ounces. The S/M quilt (fits to 6′) with a “standard” 20 x72 sheet of the same specs is anticipated to weigh 2 pounds, 2-3 ounces (I’ll know for sure when it gets here later this week).
