Suspended Sleeping System Review

From: Charles Lindsey, 9/4/02
Type of Gear: Shelter/Sleeping System
Name of Gear: Suspended Sleeping System
Manufacturer: Center of Gravity Inc.
Capacity: One person / 300+ lbs.
Weight: see Weight below
Cost: $265.00
Reviewer's Height/Weight:
Charles, 5'9", 170lbs

Suspended Sleeping System in its Backpack
Note: the pack rain cover pictured here does not come with the S3.



Introducing the Suspended Sleeping System (S3). The S3 is an all-in-one system featuring:

  • beltless backpack,
  • hammock,
  • sleeping bag,
  • mattress,
  • bug netting shelter,
  • separate fly/awning
The sleeping system comes neatly packed inside the backpack, which is large enough to carry additional gear. The sleeping bag, mattress and bug shelter are integrated into the hammock to produce an all-in-one sleeping system. The rain fly easily attaches and also functions as an awning.


Suspended Sleeping System without Rain Fly
Jamie snuggled into the Suspended Sleeping System (without the fly attached)

Suspended Sleeping System with Rain Fly
The S3 with Rain Fly attached.

In short, the S3 provides your backpack, sleeping bag, mattress and tent, all in one 9 1/4 pound package.

Based on my usage of the S3, I've made a few notes and observations below that you might find interesting and/or useful.


The system includes backpack, hammock with integrated sleeping bag, mattress, bug screen and separate hammock rain fly/awning.

Tested weight:  

  • total weight:   9 pounds, 4.15 ounces (4200 grams)
  • backpack alone: 9.49 ounces (269 grams)
  • rain fly/awning: 1 pound, 12.33 ounces (803 grams)
  • system without pack or rain cover: 6 pounds, 14.34 ounces (3128 grams)
Tested packed size:
  • 10 inches deep x 15 inches wide x 20 inches tall (sleeping system with no other gear inside the pack. Size will vary depending on how you roll or fold the sleeping system)

  • 10 inches deep x 15 inches wide x 20 inches tall (sleeping system with the gear below stuffed inside the pack along with the sleeping system):

    • pur hiker water filter
    • two 16 ounce water bottles
    • evernew Cook pot & primus stove
    • one 7.8 oz canister of fuel
    • food for two days (freeze dried primarily)
    • equinox sil-nylon small pack rain cover (S3 doesn't have pack lid)
    • first aid kit & emergency kit (tp, photon light, small knife, etc.)
    • mec northern lite primaloft pullover
    • marmot pre-cip rain jacket

NOTE: the pack pictured at the top of the page includes all the additional gear listed above and weighs 22 pounds.

TIP: in order to successfully get this much additional gear into the S3 pack, you will (1) need gear that is small and/or packs small and (2) need to pack in such a way as to use virtually all available space.


We found all the components to be of good quality and the construction, with exception of dangling threads at the tie-off point in a few places, was also good. I found that the sleeping bag's zipper track, at the boot bag end, was not properly sewn shut so that the zipper track kept popping open at that end. Other than that, no quality or construction issues noted. Overall, good, especially considering this unit is an early prototype.


The backpack, rain fly, hammock and sleeping bag shell all appear to be constructed using the same coated, water resistant, heavy-duty, rip-stop nylon. Having tested the rain fly with rain as well as a garden hose, we can say that the material is water repellent.


A well-made ultralight rucksack weighing 9.49 ounces. This pack is useful by itself. I've found very few (none actually) beltless rucksacks that are comfortable for me. This one is more comfortable (a.k.a. less uncomfortable) than others that I've tried primarily because (1) its shoulder straps are well padded and are three inches wide. The extra-wide straps provide more body coverage and thus do not dig into my shoulders as much and (2) the bottom of the pack sits directly in my lumbar region which provides a good fit, good stability as well as supporting a wee bit of the weight. The pack has a large external mesh pocket used primarily for carrying the hammock rain fly, but is large enough to squeeze in a water bottle and pair of wet socks. The padded hammock provides a supportive and comfortable backpad. A simple, yet practical and functional pack.

Sleeping Bag:

The sleeping bag is sewn to the hammock at the sides, with the mattress as its bottom. It is constructed of what appears to be expedition-weight fleece laminated to a ripstop-nylon shell. The bag has a full-length double zipper running down the middle of the bag. The bag is sized generously. I initially thought that the bag could have used a zipper draft cover, but as it turned out the bag is large enough that I just overlapped the zipper with excess bag. Keeping in mind that the hammock probably has a weight limit, the bag is large enough to accommodate anyone up to about six foot five inches tall. The sleeping bag does not have a hood so one will need to wear a fleece or wool cap when needed.


The mattress is built-into the hammock and is, essentially, the bottom of the sleeping bag. It appears to be 1/4" closed-cell foam sandwiched between a layer of rip-stop nylon on the outside and a knitted nylon covering on the inside.

Bug Screen:

The bug screen, which runs the length of the sleeping bag, has its own separate zippered closure. It has a double YKK zipper at each end of one side of the hammock, which runs 1/2 the length of the hammock. The zippers meet in the middle, at which point there is a vertical zip which extends to the other side of the hammock. This three zipper configuration allows for ease of hammock entry and exit. Similar to the rain fly, the bug screen does not have a separate rope nor does it connect to a line stretched over the hammock. Sewn to the hammock, it is cut a little shorter than the rest of the hammock such that it will stay up on its own if the hammock is properly taut. As you pull the hammock out further, the shorter bug screen will rise up and create tension across the top of the screen to hold it up. When not in use, it can be secured to the sides of the hammock using strategically placed velcro straps.


The hammock is mostly a composition of all the parts being described here. The construction is not lightweight by any means. The materials are noticeably durable, from the heavy-duty rip-stop nylon and the heavy-duty webbing on either end which houses the heavy-duty D-ring which attaches to the 1/4" anchoring rope, this hammock will last for awhile.

Under the mattress is a pocket which runs the length of the mattress into which can be inserted one or two thicker pads to provide added insulation. Of course, the pocket area can also be used for storage of clothes and other gear. At the end of the sleeping bag is a zipper-enclosed "boot bag pocket" into which boots and shoes can be stored.

Hammock Fly/Awning:

The fly is a rectangular section of coated, heavy-duty ripstop nylon. It has grommets at each corner and also the center edge of each side. The fly does not have a separate rope nor does it drape over a line stretched over the hammock. The fly has an attachment on each end whereby it connects to the each end of the hammock. This attachment results in a taut fly (assuming the hammock is set up properly) which can then be tied down in various configurations. The fly can be staked out or tied down at virtually any angle. One feature that I appreciate, which gives the S3 great storm worthiness, is that the edges on each end are velcroed. The ends can be completely sealed shut so that together with the sides being properly staked out, creates a tent effect. A stick may be used to prop open a ventilation space at the top of each end of the sealed-shut fly.


It was easy to set up. Keeping in mind that "I need instructions", we set it up without instructions the first time in about ten minutes. Subsequent set up time was faster. It's pretty intuitive - with one exception. The only feature not obvious to me was the "no knot connector" at the end of the rope at one end of the hammock. Here's the word I received from the manufacturer:

"The no knot connector is very simple but I guess needs some explanation. The one end at the head is just a hook that can go back on the line or the D ring after going around the tree or what ever a couple times (I got this one no problem). The other connector is adjustable (this is the one I didn't grasp right away). You pull out the S3 on this end just enough so the bug screen goes up and then go around the tree a couple time to take up slack. Then move back down the cord now supporting the S3. When you have reached the point where the line is tight ( some where between the S3 and the tree) you push a loop of the now tight line through the empty hole in the connector, and loop it back over the connector end. This will hold the S3 and can be adjusted by where you locate it."
I was surprised how easily the system returned back into the pack. I was anticipating it to be one of those situations where the factory squeezes it in the package okay, but once it's taken out, it will require a bag twice the size of the original to repackage it. Not so! The hammock, mattress & sleeping bag folded up easily and neatly and slipped back into the pack.


Weather Resistance:

The coated rip-stop nylon used to make the shelter is adequately water repellent. The ends can be sealed shut thus providing a storm worthy shelter. The sides of the fly, as well as the hammock can be staked down to provide additional stability. The rainfly, when stretched out as an awning, keeps the hammock and the ground under both sides of the hammock reasonably dry. This is a nice feature for use in the Pacific Northwest where we get drizzly days requiring some rain protection but not enough to lower the rainfly awning all the way.

Use in Cold Weather:

For use in colder weather, the S3 has two features which extend its potential utility. Firstly, as already discussed in the components section, under the mattress is a pocket which runs the length of the mattress into which can be inserted one or two additional pads for added insulation. Secondly, the sleeping bag is oversized such that you can insert another sleeping bag inside, in order to extend its temperature rating. I put my 15 degree Western Mountaineering Versalite bag in the hammock, crawled inside and then zipped up the S3 sleeping bag over top with room still to spare. If you would like a hammock apparently flexible enough for cold-weather use, you might take a look at the S3.


Swaying in the wind is good. Soft mattress is good. Thick fleece sleeping bag is good. Entry and exit of the hammock was not a problem to either my daughter or myself. Overall, a comfortable sleeping system and shelter. As earlier mentioned, the backpack container for the system provided a relatively comfortable carry (for a beltless rucksack) with a total of 22 pounds.


After examination and use of the S3, we had the following comments pertaining to potential improvements of the S3 product. Keep in mind that the S3 we have been testing is a prototype and these suggestions have been forwarded to the manufacturer. So, one or more of these ideas may well be incorporated into the production product (see manufacturer's response below).

  1. a netting pocket on each side of the pack wouldn't weigh much and would provide easy access to water bottle, snacks or other frequently needed items.
  2. add 2 inches to the length of the pack shoulder harness straps so the pack can be lowered onto the buttocks for heavier loads.
  3. consider all system components and make things lighter wherever possible without compromising strength or adding cost.


The following update and comments are from the manufacturer:

The S3 it is different from other hammock tents on the market. It is a complete sleeping system and it is constructed differently. It is sewn in such a way that allows you to lie out flatter on your back, and easily on your side. I am not sure that you can do this as well with the other products and it is due to the unique construction found only on the suspended sleeping system. This makes a very comfortable sleeping arrangement and more compatible with normal sleep positions that people are used to.

The S3 is a new and different concept that replaces a lot of heavy camping gear and it can be used as a sleeping bag in the conventional manner.

We have made some improvements as you suggested and made the back pack straps longer and are providing a side release clip so that you can attach the empty back pack container within reach to access things while you are in the S3. The back pack container also makes a good pillow when stuffed with clothing. We have had over 300lbs in the prototypes with no problems. It is over-built but we think that is important for safety reasons and durability. Better heavy than fragile.


In our opinion, a well thought out, comfortable, solo shelter and sleeping system. My 23 yr old daughter and I are both impressed with the product.

For two to three day excursions, I recommend taking a look at the S3 - especially if you like the simplicity of beltless rucksacks and hammocks. The system is practical, economical, convenient and comfortable. Check it out for yourself.


Website: none


Snail Mail:

Center of Gravity Inc
1629 Route 173
Chittenango NY 13037


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