Q. for Tim Marshall and the Cuben quilt club

[mark cole]

Ok, want to get a new quilt and want it to be 3 season. I'm a cold sleeper. Was thinking of Tim's Cuben design w/the skunk stripe of Momentum. What if I had Tim put a 15-18" stripe of Momentum both top and bottom for breathability and make the rest out of Cuben? Does this make sense?

[Steven Evans]

This is definitely a question best answered by Tim, but if you put a breathable strip on the inside then you will lose the vapor barrier effect.

[mark cole]

Don't want vb effect. Want a super light 3 season quilt.

[BlackHatGuy]

Don't know that I'd want a stripe on both sides, as I don't know that the top one would breathe well enough to keep the down from getting wet if you were perspiring a lot.

FWIW, I use my quilt as a 3.5 season quilt simply by either tucking it around me for the cold, or just laying it on me with the footbox unzipped for warmer weather. Well, actually, in summer I use my Arc AT — wicked light and plenty warm.

[Bob Gross]

Actually, if you minimize the Momentum and maximize the Cuben, it will be lighter.

–B.G.–

[Lynn Tramper]

"Actually, if you minimize the Momentum and maximize the Cuben, it will be lighter."

Agree, though at some point it will take so long to loft (without adequate momentum) that it isn't worth going any narrower?

Not sure about having the Momentum on both sides either. Seems to me it would just be asking for all that pent up cuben trapped moisture to channel through a small area to get to the other side, and praying it doesn't escape sideways into your down. Ditto trying to dry now damp down…likely to get a lot of condensation on the inner surface of the cuben, but I'm just speculating.

[mark cole]

Hmmm… interesting. I would have thought all the moisture would head straight up through both layers of Momentum. What you think Tim?

[Derek Goffin]

No I think the moisture will dissipate in all directions and condense on the coolest surface. That is likely to be the inside of the outer layer of the quilt. The cuben will make it difficult for this to dry out afterwards.

[Tim Marshall]

Ditto on what Derek said.

Under most situations you may not have a problem with the vapor passing though both layers. In high condensation conditions however the vapor won't make it all the way through in one shot(correct me if i am wrong) and this is when the problems will begin. If the vapor condenses to the underside of the m90 it will drip and then migrate to the areas of the bag that are cuben. Once the condensation vaporizes again (happens all night right, back and forth)it will not be able to pass out of the bag and then you are looking at the possibility of wetting out your down.

A better approach to make the bag more usable in warmer temps is to reduce the loft. I know that it makes the bag more specialized, but to be honest from the beginning we expected these to have a more narrow temp rating.

I think you could roll the dice and take the gamble and test the first momentum center cuben winged quilt, but how it will perform is very much theory vs proven fact.

If the ultimate in lightness is the goal go cuben/with m90 stripe and do sewn through with 1" loft. That quilt will go all summer (if you don't expect to bundle under it) and into fall spring with no issues. (where i hike *midwest*)

-Tim

[mark cole]

Food for thought. Thanks for the input guys, Mark

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