The ultra-light backpacking folk have latched on to Cuben, especially for tents. A so-called "waterproof/breathable" Cuben fabric has recently been developed, and the ultra-light backpacking folk are enamored with rain gear made from it. But alpinists haven't gone for it in a big way, yet. Is that because it's so new, or are there fundamental problems with "waterproof/breathable" Cuben in alpine pursuits? Anyone out there have experience? I am wondering about durability in thick brush during approaches, and on sharp rocks higher up. Also wondering how quickly it wears out, and what degree of water resistance and breathability the stuff has. There is a lot that one might love about "waterprooof/breathable" Cuben (esp. the super light weight), but what is the reality?

A few minutes' googling indicates that "Cuben" is a brand name for the output of a particular corporation; it doesn't indicate any particular fabric. Stuff labeled Cuben seems to be a multi-layer material; it appears the manufacturer recently switched to eVent for one of the layers. EVent has a good reputation as waterproof/breathable membranes go: somewhat more breathable than Gore-Tex, and I haven't heard any complaints about durability etc.

I haven't tried eVent but i found gore-Tex rather inadequate - it doesn't feel breathable to me. I did some reading a while back and concluded that goreTex does allow moisture to pass, but only after the interior is nice and swampy. E-Vent was measurably better, but not enough better to make a real difference to me.

I assume the tech continues to improve, but I haven't seen anything that makes me question those conclusions yet.

Cuben is a laminated fabric composed of Ultra High Molecular Weight Polyethylene fibers (Dyneema, I think). As you can imagine, Cuben has a high strength-to-weight ratio; thus, its allure to light-weight enthusiasts.

Nartreb is correct about the recently introduced “waterproof/breathable” Cuben being laminated with EVent. My understanding is that there are two layers of EVent: one on either side of the Dyneema. That double layer of EVent sounds nice in theory, but EVent is very thin (on the order of ten microns thick). And the Cuben part of this laminate is quite thin, too. That’s why the “waterproof/breathable” Cuben rain jackets that ZPacks makes weigh only 133 g or 4.7 oz in a size L. (I am not promoting this item, but FYI, the url for this jacket ishttp://www.zpacks.com/accessories/wpb_jacket.shtml ). At that weight, you can understand why one might be skeptical about the durability of “waterproof/breathable” Cuben, eh? That said, Cuben has made a big splash in sailboat racing. For terra firma, Sierra Designs is the first major outdoor equipment manufacturer that I know of to have come out with a (non-breathable) Cuben tent; it’s super light, but you don’t want to know how much it costs. “Waterproof/breathable” Cuben rain jackets are not as pricey. I might end up purchasing one of these, but I hate to be the guinea pig if others have already tried these jackets in alpine settings.

Interesting - that jacket is about 1/2 the weight of the lightest shells that I could find (around $400 each), and 1/3 or less of the weight of a "normal" shell ($100-$200). I'm in no hurry to replace my rainshell (it's not heavy, and mine has pockets), but if you could get that kind of weight savings in a tent (without breaking the bank) I'd be interested.
Dyneema is pretty strong stuff (frequently used in slings for rock climbing), stretches less than nylon, and is UV-resistant enough for outdoor use. No reason it shouldn't work in a tent.

>you don’t want to know how much [the tent] costs

You were quite right. For about 100 grams more, the otherwise identical Mojo 2 is 1/4 the price.

FWIW here is a USA based company that makes Cuben Fiber products:http://www.hyperlitemountaingear.com/

I've seen the ice packs and they are very appealing!

GlacierCountry wrote:FWIW here is a USA based company that makes Cuben Fiber products:http://www.hyperlitemountaingear.com/

I've seen the ice packs and they are very appealing!

someone here on sp (can't recall who or i'd give them credit) turned me on to hmg. they put out some good stuff.

six moon designs makes an ultralight cuben fiber tent as well. well, actually they make several, but the top o' the line is this bad boy:

http://sixmoondesigns.com/tents/ssX.html

tent, stakes, and pole add up to a combined (just under) twenty ounces.

Well, alpinist isnt using cuben fiber because it has terrible abrasion resistance it's about as abrasion resistant as fine Mylar which is exactly what it is, instead alpinists are adopting woven dyneema check out cilo gear to look at there packs, i think it has somthing to do with cost as to why dont get dyneema jackets.

Those Cilo Gear backpacks do look nice (although pricey). As for Cuben: note that standard Cuben fiber does have a Mylar layer, and has poor abrasion resistance, but "waterproof/breathable" Cuben has eVent layers rather than Mylar (Mylar would not be breathable). eVent not so durable, either, but the newest twist to "waterproof/breathable" Cuben is an added outer layer of nylon. Thus, the durability issue may be changing soon.

It may increase abrasion resistance but seriously by how much? The nylon they use must be super low denier to keep weight still relatively low, i mean are you ever really hanging weight of your jacket (cuben fiber jacket may be good as an **EMERGENCY** anchor point in snow :O) because if your not why do you really need that tensile strength? I understand it as an ultralight backpacker though as an alpinist i really dont see the point. Any way back to my main point if you add a 1000 denier layer of nylon on the bottom of the pack for abrasion resistance why not just have the 1000 denier sil-nylon. I think the next step for alpinists are woven dyneema shells with a gore-tex pro laminate IMAGINE THE POWER, it would be super abrasion resistant even stronger than cuben fiber as long as it's executed well that is.