Marmot Phase Sleeping Bags – Good update to the Plasma line?

Ask Marmot (?)

Physics is physics.  There is no magic. Lower fill power down AND lighter total weight with a similar temperature rating?

… are they gaming the system now?

I’d say that is likely.

Marmot can

-Make the bag shorter

-Decrease the girth of the bag

-Put in a shorter zipper, eliminate other features

Buy one from REI and return it if you think it is not rated correctly.

Answered my own question — Here’s a good picture I made by super imposing the Phase on top of a Helium (its cut very similar to the plasma). I think that is the bulk of the savings there..

The en rating is based on a dummy lying in an unnatural position with the convection fan blowing straight down on it. Knowing this you can make a bag that will ‘fool’ the tests, such as having a less breathable top fabric to offset the fan that blows from the top.  In the real world unless you sleep in the same position as the mummy, and your tent somehow has the wind enter from the top only, the bag may not be as warm.

The details of the test were told to me by designers from Mtn Equipment. (‘Dr. Down’) so i believe him.

Not sure what marmot is doing, just saying, the test isnt necessarily representative of an actual night in the bag. (Any bag)

or… decreased girth… is it comfortable?

I bought an LL Bean -20 F. winter bag with 750 fill goose DWR treated goose down.

So no, it isn’t as light as the 850 fill Eddie Bauer Karakoram -20 F.Bag I returned to EB but it sure as he!! has a far better collar and hood setup and equal build quality. The EB collar was at my nips and had no zipper side closure or drawcord! “Guide Tested” indeed…

I gave up a bit of compressibility and more weight for much better design and an unbelievable sale price. The details of the LL Bean bag are the best I’ve ever seen and I have a WM Megalite 3 season bag. In fact Bean’s sold out of them last year and again this year. All they have left is 0 F. winter bags.

So it ain’t always the absolute lightest weight that’s the most important feature.