eVENT tents and Exchange Lite

[Anonymous]

Many people were disappointed by the withdrawal of eVENT from use in tents, and some refuse to recognize that Exped is still making their Polaris tent from eVENT while marketing it under a generic “3-Layer PTFE” name…

Little notice has been given to the remaining stock of Outdoor Designs tents that were made in “Exchage Lite Gore Tex”. As everybody knows, Outdoor Designs is a British company (reviews of their products on this site); from 2006 their tent and bivy line was taken up by Rab. While Rab has officially switched the fabric used to eVENT, they have officially discontinued making tents. They kept the old OD Summit Extreme design because it’s very low 28″ ceiling height was low enough NOT to be considered a tent domicile under under the relevant fire codes. But Rab is not planning to remake the other former Outdoor Designs tents such as the Summit Raider that had a higher ceiling.

Some stock remains of the Outdoor Designs tents made in Exchange Lite Gore Tex. This includes the Summit Raider (the dimensions of which are similar to an ID MK I Lite), as well as two other larger, specialist geodesic mountaineering tents.

The story behind Gore Tex Exchange Lite has never been told, but everything suggests that it was really just eVENT that was licensed to Gore. It was not available in the States. It was exclusively marketed in Britain. Yet unlike Gore Tex which uses a PU layer to maintain full waterproofness (hence preventing gas exchange), it is air permeable–hence the name “Exchange Lite”. If Gore has their own proprietary air permeable PTFE mebrane that did not require PU to maintain waterproofness, why the heck wouldn’t they market it everywhere they could? Unless, of course, it was licensed to them under very specific terms.

The eVENT fabric that Rab is now using to make the old Outdoor Designs models is called “Exchange Lite eVENT”. Sounds familiar, eh? This fabric is 8% lighter than the old Exchange Lite Gore Tex. Both are air-permeable. Both are more breathable than PU-based PTFE formulas such as Gore Tex, Todd Tex, and Tegral-tex.

Some of the remaining Outdoor Designs tents can be viewed at a website in Britain:
http://www.outdoorgb.com/sshop/prod_info.asp?path=summit_raider_goretex_exchange_lite_single_skin_tent

There is also a site in the States that is selling some:
http://www.backcountrydeals.com/product_info.php?cPath=48_29&products_id=84

If you wanted an eVENT tent but DON’T want the Exped Polaris for some reason this is probably your last chance.

[EndoftheTrail]

Hmmm… I wonder if the “included vestibule” is the same awkward, add-on type like the Black Diamond Firstlight — or an integrated vestibule like the Big Agnes Seedhouse tents?

Also curious why you choose to post anon.? Are you affiliated with BackcountryDeals in any way?

[Woubeir (from Europe)]

I don’t think BHA licenced eVENT to Gore. The air permeable gore-tex is just gore-tex without the PU-layer. The reason why Rab/OD call their eVENT fabric for bivys also Exchange Lite, is simply because Exchange Lite is a trademark of OD/Rab, not of Gore. Terra Nova uses the same material under the name FLO2, OR calls it Respiration Positive GTX. I believe Gore calls it Gore-tex Starlite.

[Anonymous]

Ben: no affiliations, no quest for authority. just sharing.

Tom: Gore Tex (Classic, paclite, XCR, stretch, etc) without PU is an old formula. When Gore first brought its product to market, the first generation didn’t use PU, and the garments leaked after getting dirty from use in the field. Today, GoreTex without PU is known as “Windstopper” (it used to be called “Activent”). As you know, Windstopper/Activent is not waterproof. Whatever is being used in waterproof air-permeable Gore fabrics such as Flo2/Exchange Lite etc is not just “Gore Tex without the PU-layer”. It has to be a substantially new technology.

FYI, Rab sent me this e-mail:

“You are correct, e vent and exchange use very similar technology. E vent have developed an oilaphobic (sic) coating which is applied to the menbrane on a molecular level so breathability is not affected. The main difference between the two is e vent fabric is around 8% lighter.”

So, the main points are: very similar technology, main difference is weight.

[Author]

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