Cuben Fiber has made a big splash in the ultralight backpacking scene with everything from rainwear, to backpacks, and shelters being made from it now. As more hikers and backpackers venture from the mainstream into the world of niche products, Cuben Fiber becomes a fairly common alternative to silnylon and other ‘traditional’ lightweight materials. This article will be the first of a short series dedicated to taking a look at several excellent shelters, all made from Cuben Fiber, of course.
What exactly is Cuben Fiber?
Cuben, Cuben Fiber, and CTF3 are all one and the same. We’ll stick to calling it ‘Cuben’ for simplicity sake. Cuben is a proprietary material made in the USA by Cubic Tech. To quote the Cubic Tech website: “Cubic Tech’s non-woven fabrics contain thinly spread mono-filaments of high tech fibers such as Dyneema®, Vectran®, Aramid, Zylon® or Carbon. Specialty coatings encapsulate and protect the filament layers which are organized into multidirectional reinforced panels. The fabrics have excellent resistance to delamination.”
I like this simple description from the Mountain Laurel Designs website: “Think: Small Dyneema threads in a tough UV resistant Mylar sandwich”
The material looks a bit like semi-translucent crinkly plastic (which essentially, it is) and comes in various colors. Olive Drab and white seem to be popular options for shelters. It is waterproof but not breathable. There is however, a newer variation which claims to be waterproof-breathable and it is already being implemented in rainwear and bivvy sacks among other uses. Yet another variation consists of a thin metallic layer which makes the material reflective, however there have been instances of this particular material delaminating under stress (tents, tarps), so it is somewhat unproven (or possibly proven problematic) for these applications. There are however, a multitude of Cuben Fiber products that have been put to good use in outdoor applications. The table below shows some of the common material designations and weights as given by Cubic Tech.
|Cuben Fiber Variations|
|Product||Weight (oz/sqyd)||Break Strength (lbs/in)|
Durability and Care
As with all lightweight materials, the way you treat them will have a big impact on how they hold up. While Cuben has a high ratio of weight to tensile strength (geek speak for: resists being pulled apart) it has relatively low abrasion and puncture resistance. The mindful backpacker who takes care of their gear should see good service from Cuben Fiber, however Bear Grylls types are probably better off with heavier materials. I asked Joe Valesko (a thru hiker, and owner of ZPacks) to give me a quick bit of insight into material selection for Cuben Fiber tents vs. backpacks that he makes; here’s what Joe had to say…
“I use one of the lightest weights (.51 oz/sqyd) for tents, and it is able to hold up to wind loads and the typical stress a tent gets. The trouble with using the thinnest fabric weights for backpacks is they are subject to punctures and abrasion. Backpacks also focus a lot of stress on small areas, for example where the straps attach, and that can cause the material to separate at the seams. I chose a thicker weight material (1.43 oz/sqyd) for backpacks. That weight has more Dyneema fibers and also a thicker membrane material. It has higher abrasion and puncture resistance, and it is less prone to stretching / shredding at the seams. It won’t last forever, but it has plenty of strength for an ultralight backpack. I also use a hybrid 2.92 oz/sqyd Cuben for slightly heavier/stronger backpacks. The hybrid material has a layer of woven polyester laminated to the outside. The extra layer helps prevent abrasion and fraying, and generally just gives it more strength. When it comes down to it Cuben Fiber has a higher strength to weight ratio than ripstop nylon or gridstop materials and that results in a lighter backpack.”
Yup, there are a few trade offs to go from a material like silnylon to Cuben. Usually the first to sink in is the cost – this material is expensive. Then there is durability which has already been mentioned; you’ve gotta take a little extra care with Cuben and it’s probably not something you want exposed in a bushwhacking scenario. Breathability, or lack thereof, should be considered as well. You may find your Cuben shelter a bit warmer than you’re used to, and in cold/freezing weather you may find more condensation or frost inside the tent (though most backpackers accustomed to single wall shelters should already be familiar with mitigating condensation issues). In return for all of this you get a product that is lighter and/or more waterproof than it’s non-Cuben counterpart, woo hoo!
Working With Cuben
Just to provide some perspective on what it’s like to work with Cuben Fiber I asked Judy Gross of LightHeart Gear about it. She offers some insight that DIYers, or anyone really, may find interesting.
“Cuben fiber provides a number of different challenges when sewing due to the selection of many different weights of the fabric. The very lightest cuben, will crimp and crumple up, while the heavier cuben will be stiff and drag at the machine. Any mistakes in sewing will leave permanent holes in the fabric, though these can be covered with tape.
Cuben will quickly dull machine needles as well as any cutting tools used. When sewing tents, I use thread that is stronger then general sewing thread and a longer than usual stitch – the less holes poked in the fabric the better. But, the combination of strong thread and long stitch on lightweight fabric causes issues with tension and difficulty in getting a seam to lay nice and flat. To achieve this, you have to use a “taut sewing” technique by gently pulling the fabric from the back of the presser foot.
I use all industrial sewing equipment, my machines have ‘pullers’ (this is a highly technical term) to help achieve a flat seam. A puller is a roller that clamps onto the fabric as it comes out of the presser foot; it is geared to the stitch length and ‘pulls’ it out so the stitches lay flat.
I like to tape any cuben to cuben seam after sewing it. I find the needle holes will grow a little when tension is put on the seam, so I reinforce each seam after sewing with cuben tape. When sewing over seams that were taped or glued, the machine needles often get gunked up from the glue, this is easily remedied by cleaning the needles off with a little rubbing alcohol.”
Which Manufacturers are Using Cuben?
Other than Terra Nova (who has used Cuben Fiber in their tent designs) and Granite Gear (dry sacks), the mainstream outdoor companies have been steering clear of Cuben, probably due to the lack of production facilities who are familiar with sewing and bonding it, however, more of the cottage industries are getting into Cuben. The following is a partial list of some of the manufacturers who have Cuben Fiber product offerings…
- Bear Paw Wilderness Designs
- Enlightened Equipment
- Cilo Gear
- Hyperlite Mountain Gear
- Lawson Equipment
- LightHeart Gear
- Locus Gear
- Mountain Laurel Designs
- Six Moons Designs
- Terra Nova
- Yama Mountain Gear
Contact information is available here: http://hikeitlikeit.com/directory-of-manufacturers/
Let’s Talk Cuben Fiber Shelters!
Moving on to the meat and potatoes… I already mentioned that this series will focus on some shelters. The teaser shot below was taken near Point Reyes National Seashore (California) over looking the beautiful Pacific Ocean.
From left to right you’re looking at the following shelters…
- Locus Gear, Khufu (article here)
- Lawson Equipment, Fast Packer (article here)
- ZPacks, Hexamid Solo Plus (article here)
- LightHeart Gear, Solo (article here)
- Hyperlite Mountain Gear, Echo I (article here)
- Mountain Laurel Designs, Solomid (article here)
Seeing them all together with the Pacific as the backdrop on a bluebird January day made for quite a sexy scene indeed. A passing hiker couldn’t help but whistle… at least I think he was whistling at the tarps and not my torso glistening in the sun… hmmm, anyway!
I selected these shelters to showcase a few different designs and construction techniques. The Locus gear and MLD shelters are both pyramids. Similar in size but differing in construction with the MLD being bonded, whereas the Locus Gear is sewn (among other differences). The Lawson Equipment tarp is a straight forward catenary cut tarp while the HMG is a catenary cut tarp as well, it is part of a shelter system composed of the tarp, beak, and inner tent. Lastly, our picks from ZPacks and Lightheart Gear showcase a ‘tent style’ design with built in floor, bug netting, and zippered doors. In essence, there should be something here for everyone.
Now that we’ve had some time to hike with and sleep in each of these shelters we’ll be reviewing each in the coming weeks. Stay tuned… there will be quite a few photos and details forthcoming! In the meantime, if there are any questions, don’t be shy!
Hike It. Like It.