[at-l] Sleeping Bag Ratings Question

nightwalker.at at gmail.com nightwalker.at at gmail.com
Sun Jan 17 13:50:07 CST 2010

From: Daniel Steil <dsteil19 at gmail.com>

The quality of down fill (i.e. 850 or whatever it may be) doesn't necessarily indicate warmth.  All the numbers mean is how many cubic inches of space one ounce of that weight down can fill ( one ounce of 800 fill takes up 800 cubic inches of space) .  The number that really matters in down bags is the fill weight of the down and to me is a better indication of warmth.
The down quality generally means that the higher the number, the lighter the bag--since they have to use more ounces of lower-numbered down to get the same thickness.  Also, it seems that anything below 750 has a LOT of feathers included at no extra charge. :-)

The Kelty Light Year 25 comes to mind. 600 or 650 down and supposedly a 25F bag. But I've seen people come out of one at 35F really freezing/shivering.

That, of course, goes back to sleeping warm/cold. In a 65-degree house, my wife will be bundled up like it's snowing and I'll be in boxers and barefoot.

One other BTW. I know a guy with 2 thrus tha( starts and finishes every day listening to one of those little plastic radios that only weekenders carry. :-) What reminded me of that is that he carries a sleeping bag that isn't warm enough, but uses a homemade liner made from a seriouly non-breathable ground cloth. He sweats a bit, but he doesn't freeze.

But, as I've said, the number that counts to me is the number of inches in thickness that is above you in a given bag. Higher power fill numbers give more inches for less weight. 12 ounces of 850 down means a 30% increase in cubic inches of fill compared to the same weight as a 650 down bag. The higher-numbered down also compresses smaller. I've seen an 850 down, 35F bag that goes down to the size of a small canteloupe. My pretty-darned-good 750 down 30F bag goes to the size of a flat-ended football. Not bad. But if it were 850 down it would go down to that canteloupe size.

I think we're getting down to hair-splitting. Let's switch the discussion to "how many angels can dance on thew head of a pin." Even better: "how many pixies/fairies can be crushed between the pages of an average sized book."

Discuss it to death
Then dissect it

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