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Nov 9, 2010 at 10:27 am #1662517
just as a note that of all the bags being discussed only the WM has an en-rating which ive already posted …
does it matter? … that depends on how much vulcan there is in yr blood ;)
Nov 9, 2010 at 10:30 am #1662522The information that Eric posted didn't show a conservative rating for the WM Summerlite. It showed a vendor Comfort rating of 32F and the EN 13537 test rating of 35.6F.
Nov 9, 2010 at 12:13 pm #1662547It did show a difference of 3.6 degrees. However, most people who have used a variety of bags, including Western, have found that the WM bags are closest to their ratings. Anecdotally, my Antelope (5*F) keeps me warm below 0*F, my Summerlite keeps me warm a little under freezing, & my Mitylite right to 40. But anecdote is not science!
When it gets down to it (sorry, pun intended), if you have one bag with 70" girth and another with 59" girth… and both have the same amount of insulation in them, then the wider bag inherently can not be as warm as the narrower one. You're trying to use the same amount of insulation to fill much more area, which will lead to less loft.
I would be interested in seeing EN ratings for the MB bags, non stretched & stretched. I would be surprised if they were as close to their rating as the Summerlite.
Nov 9, 2010 at 3:55 pm #1662643Not buying it. If you fit inside a the 59" girth of the SummerLite, the down won't be spread more thinly when using the Montbell bags. Unless you decide to sprawl out uncontrollably [*] just because you can. :)
If we opt to toss out anecdote and stick to science, the Montbell #3s will be just as warm or warmer as the SummerLite for anyone who uses up to 59" of shoulder girth; anyone who needs more will likely be warmer in the Montbell #3s because of compressed and/or shifted down. The SummerLite's differential cut allows some wiggle room in where the bifurcation point between MB ~= WM and MB > WM, but it doesn't make a difference whether it's 59" or 62".
The MB bags would both be warmer than the SummerLite for anyone with a shoulder girth below 59", as the shoulder girth starts at 56.7" and 53" for the Spiral and Super Spiral respectively.
Science is often driven by anecdotal experience, if not strictly supported by it. One area we haven't looked at is shell fabric in varying conditions. Fabrics used on the SummerLite may or may not support the warmth of the bag more or less than the Montbell bags. I wouldn't even know where to start with that one, if indeed the advantage went to one or the other.
I merged and corrected our specs:
MB UL Spiral #3 – $249
Weight: 19 oz
Fill: 9.4oz @ 850 equiv
Shoulder: 56.7-68"
Knee: 45.7-54.9"MB UL Super Spiral #3 – $279
Weight: 21 oz
Fill: 9.4oz @ 850 equiv
Shoulder: 53-75"
Knee: 44-62"WM SummerLite – $315
Weight: 19 oz
Fill: 9 oz @ 850
Shoulder: 59"
Hip: 51"* Yeah, this wouldn't work well in 30 degrees:
http://www.moontrail.com/details/montbell/down-hugger-3/dh3-ss-illustr.jpg(how do you post a photo? this is the image I mean- click here.)
:D
Nov 9, 2010 at 4:23 pm #1662658Identical 3 season bags, one filled with 800 fill and the other 850 fill lab test with an average 2.1% clo difference. How was a down equivalence value of 9.40 calculated versus?
10 * (1 – .021) = 9.79?
Eric – Thanks for the WM EIN 13537 ratings… great information find in combination with skillful use of translation.
Nov 9, 2010 at 4:39 pm #1662664Richard – I think he arrived at 9.40 oz by doing:
10 * (800 / 850) = 9.41
Or, keeping units:
10 oz/800 fill * (800 fill / 850 fill) = 9.41 oz/850 fill
Wasn't my error this time around, but I've done the same thing before when comparing bags myself. Hell, I've a spreadsheet full of sleeping bags I was considering at one point with down standardized 800 fill calculated that way.
But I've seen the light! Do you have any more info on this? I've seen some of your other threads dealing with relative warmth of different insulators, so perhaps I should look at those before asking. Thanks Richard!
Nov 9, 2010 at 4:50 pm #1662670I was communicating a concept and using those easily calculated figures as points of illustration… I can't say that in the course of presenting an idea I'm too distraught over being 0.39oz off in calculation.
The broader picture was that if people pitch the MB bags as great because they can stretch so much, it makes sense objectively to rate the bags as stretched out. There is no argument that the same amount of down in a larger space will not be as warm, given that shell fabrics/liners are roughly equivalent
I did indeed do 800/850… I was getting an idea of the amount of down used, not the clo of the material… just how much was used. Not being an engineer, or mathemetician, or having access to a lab I think my figures were quite close enough for illustrative purposes.
Geez, guys, I'm trying to be objective, not bicker over MB/WM!
To the OP, I reckon you can take this all as either would be good enough!
Nov 9, 2010 at 6:06 pm #1662685one thing that was likely not tested in the en-rating was that you could move down to the top of a lot of WM bags … at least i dont know if they test the bag in such conditions
there are other bags that meet the criteria of the OP, notably by marmot, MH and others that do publish their en ratings
its interesting that the MH phatom 45 with LESS down than the summerlite has a higher en-rating or 0C/32F
i understand that there can be a few % variance between different labs … but thats quite the difference between a 45F bag and a 32F one
all the reviews seem to indicate that the phantom 45 runs very warm … i think ill take the test at face value and get myself one of those for $185
http://www.mountainhardwear.com/Phantom™-45-%28Regular%29/OU8442_R,default,pd.html
Nov 9, 2010 at 8:12 pm #1662723I don't think anyone was intending to bicker- just having a debate in the spirit of objectivity. Like a lot of folks, I like to talk about gear and get down to the nitty gritty. Unless someone brings up something personal or gets rude, there's no reason to get offended when someone disagrees with you. If someone makes a claim that doesn't make sense, I enjoy challenging it. I also enjoy when someone challenges my own assumptions, like Richard did with the numbers we had been using to compare 800 and 850 fill down.
I like learning about that sort of stuff. A lot of other people here do too. I can't speak for Richard, but I don't think he was trying to undermine your argument or mine- he was just sharing the real world facts.
Objectively, it does not make sense to rate all MB bags at their most stretched out. You're right in saying that "there is no argument that the same amount of down in a larger space will not be as warm, given that shell fabrics/liners are roughly equivalent." I'd wager that very few users of MB bags are large enough to fully stretch their bag out in every direction, making it unreasonable to assume that when comparing relative warmth. We may as well assume that the full length zipper is completely open when rating the SummerLite.
If he is someone who wanted or needed the extra room in a bag, the SummerLite would be a poor choice regardless of how warm it is. That's why I brought it up in the my 9:12 AM post- it'd make sense for the OP to elaborate a bit on what he wants or needs in a bag other than a 30-40 degree temp rating especially before investing too much thought into this discussion. Perhaps after hearing what he has to say this'll turn into someone else's WM MegaLite vs MH Phantom 45 debate. :)
Nov 9, 2010 at 8:20 pm #1662728I just want a light bag, around this pound mark if possible. I will be using it in the PNW so if anyone thinks that going down would be crazy, it would be sweet if you could say something.
Im 5'9, 200 if that effects the choices very much
Nov 9, 2010 at 8:37 pm #1662734Just a quick note on prices. I purchased a Super Spiral #3 (800 down) late last week for $236. The lowest prices I found for their 800 down #3 models are:
MB Spiral #3 $210
MB Super Spiral #3 $236Nov 9, 2010 at 8:49 pm #1662741I doubt youd find a properly rated 32F synth bag at 1/2 pound … Current technology doesnt seem to allow it … Maybe a custom quilt
the closest would be the mh ultralamina which is tested to 43F and weights like 700g
if i had to buy a 32F syn bag id get the nf scorpio which weights 900g but is en tested to 32F and costs 130$
for down personally ill prob get tge mh phantom 45 for 185 and call it a day
theres nothing wrong with a mb #3 or a wm summerlite … As long as youre aware they may be more of a mid 30s bag … The mb spiral is of course cheaper
Nov 9, 2010 at 9:03 pm #1662745what about the lafuma x600?
Nov 9, 2010 at 9:46 pm #1662758What reason is there to assume that the MB #3 would be more of a mid-30s bag other than that it doesn't have a Mountain Hardwear logo on it? :D
Don't get me wrong- EN ratings are better than nothing. But I've seen enough questionable ratings to doubt that a WM bag with 9 oz of 850 fill down is significantly less warm than another bag with 7 oz of 800 fill down, assuming similar fabrics.
Nov 9, 2010 at 9:55 pm #1662759There may be some flaws with EN testing but it does allow an objective baseline for comparison between EN tested bags. An EN tested bag at 30 degrees 'comfort' will be warmer than an EN tested bag at 35 degrees 'comfort.' Period.
Nov 9, 2010 at 10:03 pm #1662760Not quite period. Assuming the same lab following the same procedure, close enough.
EDIT: Just ignore me- don't want to divert this thread even more and don't really have a horse in this race.
Nov 9, 2010 at 10:49 pm #1662764lol
until montbell rates their bags like all those eurobums … id rather be conservative … case in point being the summerlite which everyone says is very warm … yet tests to 35F
another one is the valandre mirage which BPL said
"The warmest bags in this roundup are the Nunatak Alpinist, PHD Minim 400, Sierra Designs Nitro 30/Spark 30, and Valandre Mirage. Three of these bags are rated at 23 F (-5 C)"
yet if you look at the valandre test for that bag, it tests to 30F lower limit comfort …
http://www.valandre.com/product_images/testresults05112010113809MirageIFT.pdf
i love their marketing spiel …
Field testers have taken the super light Mirage to 14°F (-10°C) wearing a base layer of underwear and a fleece vest. Even if these are not recommended temperature ratings (metabolism etc. should be considered), field tests have certainly underlined the extraordinary performance of the Mirage.
EN testing isnt perfect … but its like EPA gas milleage … its consistent and comparable … without it marketing departments would just make up any figure they want
i actually give a lot of credit to those companies that have their products tested … and also to ones like LL bean and Lands End that tests the rating of their clothing scientifically
ultimately do i think 1 or 2 deg matter a lot? … nope … worry about other things instead … a 5F+ gap does look funny though … and 10F .. well id consider a properly rated and tested bag
if youre young, dumb and full of … well … that WM summerlite will prob be a 25F bag for you anyways ;)
here's a sample of the variability in ratings before EN ratings …
Nov 9, 2010 at 10:58 pm #1662766…
Nov 10, 2010 at 7:07 am #1662812"Something to consider (especially for us 200+ pounders) is that a stretch bag handles additional layers with ease. This is another factor that should be consider if you plan on pushing the limits of your bag."
Good point, and this is much of the reason I selected the stretch bag. Large bags are a little too big for me, but I'm a little too cramped for comfort with an average width bag as soon as I put on just a fleece jacket.
Nov 10, 2010 at 7:27 am #1662818I had a Summerlite for a short period, it was a well constructed bag, but too constricting for me- I had a 6' bag and am 6' ~ 200#. Very little to no room for additional layers and my goal was to be able to push the bag a little, which wasn't going to happen. I traded it for a Marmot Hydrogen (a bag not yet mentioned in this thread)- I found the Marmot much more suitable for my build and goal of pushing a bag. It's not outrageously larger, but just enough so that I had the room I needed. I (and many others) have the temp rating of 30 degrees to be very close to spot on. Still a very lightweight bag w/ good construction and quality materials (including 850 down)
Nov 10, 2010 at 7:41 am #1662821Mike,
I haven't found the perfect 25° bag yet. (And the MB SS #2 isn't it for me.)I have just discovered that the Marmot line is a good fit for me. (The Megalite is to much volume and the Ultralite is to little.) The Helium, for me, is spot on at 15° with no supplemental clothing, so I'm wondering how low I could take a Hydrogen.
Regarding your "pushing" a Hydrogen sleeping bag –
How far have you pushed it, and what did you supplement with?
Thanks.
Nov 10, 2010 at 10:18 am #1662868Another satisfied Summerlite customer here. I'm 6'0", about 200#. I'm a side sleeper. It doesn't feel particularly constricting to me although it's definitely not a roomy bag. I've worn a Patagonia down hoodie sweater inside the bag which does make it slightly tight, but the combo is pretty warm. I slept out on Oct 8 in about 25F wx (with a Neo Air pad and a inside an OR Aurora bivvy) and was just slightly too warm on my upper body. I'm sure I could take my Summerlite down to 20F in this configuration. I was wearing Pat Capilene #3's, mid weight socks, and a mid weight fleece cap.
The other thing I like about the Summerlite is that I can open it up like a quilt in hotter weather and still be comfortable. It's a very versatile bag and is the perfect bag for the Southern California mountains.
I haven't taken it out in less than 25F. I'd probably switch to a warmer bag if it looked like it might get into the teens. I have a MH Phantom 15 for that (31 oz).
HJ
Nov 10, 2010 at 11:29 am #1662903Greg- I've taken mine down to the mid 20's a couple of times- pad was NeoAir w/ a thinlight pad on top, I had a ls cap 1 shirt, MB ex light jacket, R1 bavaclava, R1 pants and socks. I was very toasty, albeit I tend to sleep on the warm side.
I've had the Hydrogen into the 30's many times w/ just a base layer top and briefs and a NeoAir (w/o the thinlight pad) and have been very comfortable
If I'm not mistaken the Helium has the same cut as the Hydrogen- so fit wise should be pretty darn close
Mike
Nov 10, 2010 at 11:35 am #1662909Thanks Mike.
That helps.Nov 11, 2010 at 11:16 am #1663222FWIW, the Marmot bags have a contour cut (inner & outer shell cut the same) and seem to feel better to those kinda between sizes, as it were. Example: a gentleman in the shop tried on a 62" girth Marmot Lithium & a 62" WM Antelope, but found the Lithium more comfortable.
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