Crux down pullover: highest warmth to weight ratio?

That is seriously impressive, but I'd need to verify that weight first…

Certainly impressive if the weight is accurate. But I am not sure if it beats blizzard survival jacket – 240g (8.46 oz) and warmth of 8 togs (5.2 clo).

I'm with Steve on this one. They're talking less than 90g for a double layer of downproof fabric. That's equivalent to a 45g wind shirt, assuming the material is wind resistant, and not taking into account the thread in the sewn-through squares.

Pretty impressive if it's true.

I know of at least one occasion where the designer confirmed the weight:

"The weights are accurate.
The Halo is a haf-zip (pull-over style) so this saves weight, as well as the very light 20 denier fabric."

Certainly impressive, but as an owner of the pre-zipper and pre-handwarmer pocket MontBell UL inner, I would rather carry the weight penalty for both luxuries!!!

For reference:
MB Alpine 6 oz. 800 FP
MB Alpine Light 4 oz. 800 FP
MB UL Down Inner 2 oz. 800 FP

For comparison:

MB Ex Light
* Med total wt approx 5.5 oz.
* Fill wt advertised 1.8 oz. 900 FP down
* Shell wt T-F=S 3.7 oz.
* 7 denier fabric
* Full zip

Crux Halo
* Med total wt approx 7.0 oz.
* Fill wt advertised 3.8 oz. 750 FP down
* Shell wt T-F=S 3.2 oz.
* 20 denier fabric
* Pullover – short zip

How do they do it?
Shorter zipper helps. 1.5 oz total higher weight, plus 0.5 oz off the zipper leaves 2 oz for more down. Just wish the down tubes weren't so small. My Ex Light has the most beautiful finishing on the inside seams, but may add a few grams. I suspect MB will migrate the 7d to other pieces.
The Ex Light is .7" thick, good to ~ 30F with wind layer over, minimally active.

Hey Tom, thanks for the heads-up on this garment, I haven't heard of Crux before. I got the impression it was around 5.5+ oz. of down in the WM Flight jacket, where'd you see 4 oz?

Paul,

Although WM doesn't spec this value you can calculate it from other specs provided. The material to make this size medium jacket style, with 15 denier nylon fabric, would weigh ~4.9 oz. When BPL reviewed this jacket they said the size medium weighed 9.9 oz versus the 10.5 oz specified by the manufacturer. 9.9 – 4.9 = 5oz of down.

I wonder about consistent model weight sometimes. I weighed my Ex Light at 6.2 oz for the large, and have seen similar reported. In the BPL review *LINK* they say, “measured weight men’s L is 5.7 ounces”.

Does MB use the same 1.8 oz fill in Small thru Large, or do they now add a bit more down than the original BPL weighing? I need to go back and reweigh.

Paul,

MontBell, as well as most other manufacturers, increase the amount of down filling as the garment size goes up. For example, the MontBell Alpine is specified as having 6 oz of down for size medium. Size L has 6.2 oz and size XL has 6.4 oz.

British manufacturers use a different system for measuring the fill power of down than Americans. I dont know if 750 British equals 900 American but I do know that, from a British point of view, the American system sounds exaggerated.

Over the years, I've seen the 4 oz. for the WM Flight jacket quoted on several occasions. Backcountrygear does mention it:
http://www.backcountrygear.com/catalog/appareldetail.cfm/WE4075

I wouldn't confuse US FP ratings with European FP ratings. A fill power of 750 in Europe seems to correspond with a FP of 850 in North America.

Crux also claims to use 850+ fp down in their bags. So if there is any confusion between US and EU ratings, here it is.
so i agree w/ the suspicion that the weight doesnt jive…
montbell-7 denier = 3.7oz
crux-20 denier = 3.2oz
oh yeah?

they claim this bag with 17.8 oz of 850+ fill has a comfort rating of 32°

again, that sounds fishy

http://www.crux.uk.com/en/crux_sleepingbags_torpedo_500.php

Tom,

I looked at the URL you referenced for the Western Mountaineering Flight Series fill weight. I was curious as to why my calculations didn't match the 4 oz the URL listed. I then called Western Mountaineering's headquarters in San Jose, CA five minutes ago. I asked the gentleman who answered their phone what the down fill weight of the size medium Flight Series Jacket was. He said it was 5 oz. I then asked him if the down fill weight had varied during the years the jacket was manufactured. He said no, it has been kept between 4.75 and 5 oz every year that it has been manufactured.