UKH

How do the temperature ratings on a Western Mountaineering sleeping bag (Antelope MicroFibre Down) compare with a Mountain Equipment bag ( lightline). The lightline apparently keeps girls warm to -13 whereas the Antelope just says rated to -15 so is it comfortable at -15 or survivable at -15 and is it a girls or a boys rating?
Or less geekily which will keep me warmer?

In reply to obi-wan nick b:

I assume you mean these two:

http://www.westernmountaineering.com/index.cfm?section=products&page=Sl...

http://www.mountain-equipment.co.uk/lightline-sl (or do you?- the specs seem different from the ones you quote above...)

Short answer: Hard to say....

Long answer, comparing the two specs online, the Antelope has a higher fill weight (680g+ depending on size) than the Lightline (650g). There are other parameters that will affect warmth too such as quality of fill (which is 850+ in the ME bag, and vaguely described as High Quality in the WM Antelope- so could be anything), but the quantity will have a part to play. It is hard to compare the two though as the ME bag has to conform to new En standards on temp ratings and fill quality, which are supposed to be pretty standardised (but I find there is still some variation between brands), and the Antelope seems to be an American bag so does not have to conform to these tests.

By the way- Comfort limit of -15 quoted for ME lightline SL is exactly that, limit. Some very hardy folk will be fine at this temp, most will not feel very cosy at all. The true comfort rating is -6.

Short answer again- you kind of know what you are getting with the ME bag, the WM one is a bit of a gamble. I know which one I would choose, but others may have direct experience of the WM bag and disagree.

In reply to obi-wan nick b:

The way to compare is to consider what sort of down each has inside, and the amount. Then you also need to take into account how they are made, what sort of baffle structure they use and how the down is distributed.
There's also the issue of how well-fed and tired you are when you're in them, and what you're sleeping on and the shelter you're in. But I suppose you could regard these as constants at this point, which makes things much easier.

In reply to obi-wan nick b:

Western Mountaineering claimed temperatures seem to be fairly accurate - for me at least. I have a Versalite -12C and a Bristlecone -23C and at these temperatures I would need to have pre heated bag with water bottle and wear merino long johns / long sleeve T but they would be OK. But comfort level is very personal.

I think the WM is better designed and made than PhD bags which I also have.

In reply to obi-wan nick b:

I think there is a lot of marketing hype about super sonic down etc. As important is the sleeping mat since the bottom half of the bag ends up with little insulation since its squashed flat. The Exped Down Mat is very good and comfortable for base camp or trekking. Above Base Camp comfort gives way to size and weight.

In reply to obi-wan nick b:

Just to add to what's been said:

I think W.M. bags are all 850 plus, US rating I presume, so if M.E. are now using the US/International ratings they may be similar down. There is some info on the W.M. pages.

All our down bags are M.E. but usually bought in the sales. If I was paying retail, I would consider the W.M. bag, as the last M.E. bag had a problem with the stitching that I decided to sew-repair myself. Actually, I would consider a PHD as well.

No matter how they design the zips on M.E. bags, I always get them stuck in the fabric, though it could be my escape technique.

In reply to Dorq:

I have the same zip problem with PhD, whereas the WM have a 1" strip of harder faced material either side of the zip so it doesn't catch.

I am not that convinced about the real benefits of going from 800 or 850 or 900 down in the real world. I suspect you would need incredibly thin material to ensure it lofted fully which would be completely impractical.

In reply to obi-wan nick b:

<suck eggs> make sure these are C not F ratings to compare - the yanks use F in most of their promo material </suck eggs>

In reply to obi-wan nick b:

Comfort rating = you should sleep comfortably
Extreme rating = Sleep is unlikely but should stave off hypothermia

As for male / female rating... unsure whether this is actually the shape of the bag (yes, the sexes are different... it's true... although always a surprise to the teenagers I occasionally teach) or the highlighted differences in male/female body fat / core body temperature, i.e. Women generally have more body fat, although I've also heard it said that females are fractionally cooler (not sure about that)

In reply to lithos:

Western Mountaineering provide a Metric Spec page

http://www.westernmountaineering.com/index.cfm?section=products&page=Sl...

unusually for most USA manufacturers

In reply to obi-wan nick b:

It's worth reading up on the EN rating system that ME and other euro brands are now using (as is Marmot in the US I think). I wrote a bit about it in this review http://www.ukclimbing.com/gear/review.php?id=5328. I think it has really helped standardise bag temp ratings and I know where I seem to be comfortable with that system (although it probably doesn't work for bags designed for sub -20), and with the different levels it also gives women/cold sleeping men a better idea of how warm they will find the bag too. So it's a bit of a problem that Western Mountaineering doesn't use the same system. Everyone says they are very well designed and made bags so you can probably get a good guess of the performance from the weight of down

In reply to Snoweider:


There's a reason they don't quote fill power for each and every bag in their range. And that reason is that they use only one grade of down for all their bags.

http://www.westernmountaineering.com/index.cfm?section=About&page=Produ...

<quote>
850 Plus Fill Power Goose Down
Western Mountaineering uses the highest lofting premium goose down available for all of our sleeping bags. Our fill power claim of 850 Plus is meant to be a realistic estimate given the variability of the product and the nature of fill power test methods.
</quote>

I've never used a WM bag, but my gear-obsessed reading of many outdoor forums leads me to believe they make very high quality products, and buying one would not be a gamble.

In reply to all: Thanks everyone for the replies - I think I'm erring on the side of the WM but apparently JBs in Llanberis have both in stock and so I will try and get in to compare them. I've had a lightline for a good number of years and apart from the zip jamming it's served me well; hence the dilemma.

In reply to obi-wan nick b:

In respect to the male / female thing I think the comfort temperature relates to an average female, wearing lw base layer and in a relaxed (i.e. lying on back, hands by side) position, this user in this position will be able to maintain temperature equilibrium at this temp.

The comfort limit is the lowest temp at which an average male, same clothing, but this time in a defensive position (think foetal, conserving heat) will able to be able to maintain temp equilibrium in the bag, below this you risk injury.