November 20, 2015 8:16 PM MST - Subscription purchasing, account maintenance, forum profile maintenance, new account registration, and forum posting have been disabled
as we prepare our databases for the final migration to our new server next week. Stay tuned here for more details.
Subscribe Contribute Advertise Facebook Twitter Instagram Forums Newsletter
Water repelency of Momentum 90
Display Avatars Sort By:
(SlimJim) - F
Water repelency of Momentum 90 on 12/15/2011 14:30:24 MST Print View

When used as a bivy w/o tarp, how much rain protection does M90 offer? I see it used in a lot of bivys but it's not listed as WPB, just DWR. What's your experience?


David Olsen

Locale: Steptoe Butte
hydrostatic head on 12/15/2011 15:06:29 MST Print View

Richard tested some for me and it gave a result for Hydrostatic head of 632 mm.

Dion Dixon

Locale: Blue Ridge Mtns.
Re: hydrostatic head on 12/15/2011 23:16:02 MST Print View

So... That would make it more water resistant than waterproof?

Sorry, I am interested in this as well, and am not well versed in what the Hydrostatic Head means. Wikipedia mentions 1000-1500mm as being shower proof. That correct?

If so, the this material is really only usable for non-waterproof applications such as jackets and bivies, right?

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
The concept is. . . on 12/15/2011 23:29:30 MST Print View

632 mm refers to a pressure, expressed as a height of water, that the water resistent/proof material would resist.

632 mm = 0.632 meters = 24.9 inches = 2 feet depth of water.

Now, you are rarely under two feet of water, right? And if you are, a little leakage in your outerwear is the least of your worries. But you can actually get pretty high pressures under pack straps and where creases and folds form.

So don't take the water column height literally, but use it as a comparison. Ideally get to a location where you can compare different garments (I know REI in Seattle has a rain booth - basically a shower stall where you can test rainwear under a downpour). But generally, the more waterproof, the less breathable.

Personally, I tend towards something pretty waterproof but with pit zips and other ways to ventilate.

Very, very waterproof (and very, very cheap): trash compactor liner bag.

Very, very breathable: take off the trash compactor liner bag.

Above the collar, I like a Seattle Sombero in cold weather or an unbrella in mild / warm weather.

Paul Nanian
(PaulNanian) - F
M90 is neither waterproof nor waterproof breathable; you need a primary shelter. on 12/16/2011 09:48:21 MST Print View

M90 is neither waterproof nor waterproof breathable; you need a primary shelter.