Okay, I finally got around to measuring out the new Grand Trunk Hammock Sleeping Bag. I received this bag as part of a promo event Grand Trunk sponsored last night. I had this bag wrapped around a hammock at the event and it sure got a lot of attention.
PLEASE NOTE: This bag is a pre-production model. The folks at GT told me that they were finishing the design specs with the Chinese manufacturing plant. There may be changes to the final product so take that into account.
The bag I received did not have any hang tags. The measurements are my own.
Width at Shoulders: 31 in. (79 cm.)
Width at Foot: 21 in. (53 cm.)
(Foot tapers off to 13 in. (33 cm.) at the end)
Length: 85 in. (2.2 m.)
Weight: 45.5 oz. (1.3 kg.) (2.8 lbs.)
Head Pass-through Hole: 6 in. (15 cm.)
Foot Pass-through Hole: 5 in. (13 cm.)
Temperature Rating: Unknown (the loft is around 1 in./2.5 cm. so my best guess is that this is a 1-season, summer bag, maybe 45-50°F/7-10°C).
* Two side zippers (59 in./1.5 m. in length)
* Independent front and top drawstrings on the hood
* Synthetic fill
* Two tie-outs at the head pass-through
* Four tie-outs at the foot pass-through
* Heavy-duty shock cord on the head and foot ends
* Head and foot pass-through zippered holes with draft flaps
* An inner, zippered pocket (easily fits small electronics like an iPod or iPhone)
* Draft collar around hood
* Draft tubes on each side zipper
INSTALLATION
Probably obvious, but this bag only works with simple, end-gathered hammocks. In my testing, smaller hammocks work best (e.g., GT Nano, GT Ultralight, GT Single, ENO Single, Planet Hammock Single, etc.) based on the length of the sleeping bag.
The pass-through holes are secured with a small zipper. Unzip both holes and thread the hammock through the sleeping bag and hang the hammock.
GETTING IN THE BAG
The two side zippers unzip to 59 in. (1.5 m.) on both sides. I found that if both zippers were open, the bag really flopped to the ground. I kept the left zipper up and the right zipper open. This made it easy to enter the bag and hammock.
To zip up the bag, I turned the bag so the left-hand zipper was on top and I was able to easily close up the bag. The draw cords are on the left side of the hood, so I had to turn and straighten the bag to grab and then cinch the drawstrings.
GETTING A FLAT LAY
This sleeping bag is narrow, very much a mummy-style bag. What does this mean for a hammock? Well, it makes it difficult to get a flatter, diagonal lay. With a foot and head hole at only 5 in. (13 cm.) and the bag only 31 in. (79 cm.) at its _widest_, having a hammock any wider is not only a waste of fabric, but unnecessary. The small openings and narrow bag width also restrict how far you can move left-to-right or vice-versa.
To get a "flat" lay, you'd really have to string a hammock very tight, almost horizontal. Hopefully most people know that this will result in excessive force and stress on the hammock and the suspension lines and anchor points. This is just a little dangerous. As you can see from my photos, I had a slight sag in my hammock. I could only slightly move into a diagonal, but you can see from the shape of the bag that if you try to slip into a diagonal position, you also work against the design of the bag, in particular, the hood. From everything I can tell, this bag was meant to be slept in a straight position.
The hammock used in the photos is the single camouflage hammock from Planet Hammock. I typically hang this hammock with a much bigger sag and can get a nice diagonal lay without the sleeping bag.
INITIAL THOUGHTS
The biggest issue for me is that this bag constricts the diagonal lay of a hammock. In my opinion, the diagonal lay is the single most important selling point for a hammock to achieve the comfort we rave about. Without the diagonal lay, I'm stuck in a "banana" shape and my legs quickly feel strained.
With the synthetic fill and minimal loft, I would speculate that this bag would be best in the warmth of summer. The zippers would allow for a lot of venting if necessary. Testing in my house at 65°F (18°C), I was comfortable. I haven't tested this bag outdoors yet.
Personally, I'd prefer a single top/center zip instead of the two side zippers. The side zippers are not easy to pull up once it passes my hip. Turning the bag so the zipper was in front of me made the process easier.
I've used a DIY pull-over bag for an entire winter season a few years ago. That bag (a down-filled Kelty Galactic 35) was rectangular with no hood. Using a small hammock (the GT Nano), I was able to get a minor diagonal hang, but with a lot of shoulder strain. It's not my ideal set-up. The pull-up bag was warm, and I liked that, but I had to sacrifice some comfort.
I'll wait to hold off any final review until I can see and perhaps test the Grand Trunk Hammock Sleeping Bag in its final form.
Here you can see the hood draft collar and the inner zippered pocket.
ABOVE: This shows the draft tubes on the side zippers.
ABOVE: This is me laying inline with the hammock and the bag.
ABOVE: This is me trying to go "diagonal." Not much difference.
ABOVE: I dropped the hammock lower for a deeper sag, removed the bag, and got a flatter, diagonal lay. I couldn't get the bag over me in this position.
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