After Down.

What is the best / latest & greatest synthetic fill for a sleeping bag?


Any recommendations for a 32 degree synthetic sleeping bag?
Commpressability & lightness being the key.


Thanks,
Doug


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Edited by Hustler on 03/29/2007 05:01:15 MDT.

The 2007 TNF Fission using Climashield XP looks pretty good to me. TNF says it's a 20F bag, probably meaning 30F for most of us.

Is that a new one, I cannot seem to find it?

Doug



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I second the Climashield.
It is much lighter than the 2.5 ounces per yard claimed and the thickness is a good .75".
The only bad thing is it clumps in some spots.

I guess the company is working on that. They also are saying they have fixed a few things with it to give it a new Clo of 2.0, (strait from Ayce). This is the 5 ounce version with the 2.0 rating.
I an not sure if the 2.5 ounce version will benift from it.

I cut out equal pieces of the 1.8 ounce Pre-quilt (claimed to be 2.2 with the scree added) and the climashield.

The Prequilt came in at 6 ounces while the Climashield came in at 4 ounces.
This is a 1/3 weight difference.
With 2 layers of Momentum the Pre-quilt was 75% of the total weight of the complete Momentum Climashield item.

I will not sacrifice cutting a 36" X 36" piece in order to weigh it but something is wrong in the math department.

They must be in line for a top government job if the business doesn't work out.

Edited by awsorensen on 04/01/2007 14:25:31 MDT.

Check REI for the new Fission, Doug.

I'm sorry, Aaron, but I am having trouble reconciling your figures with those shown on Climashield.Com for their XP. See http://www.climashield.com/pdf/Climashield_XP_Spec_Fact_Sheet_for_CS_Our_Products.pdf (1.1meg of PDF)
You say the thickness is a good 0.75 inches, so using their figures for 0.8" thick XP we get a weight of 4 oz/sq.yd. Using their figure of 0.77 Clo/oz gives a Clo value of 3.08. If Ayce gave you a Clo of 2 it must have been for a different thickness.

Can I take this opportunity to get on a hobby horse of mine about a common mistake in quoting "Clo" figures. A Clo is a measure of how resistant to heat loss a particular arrangement of thermal insulation is. If one layer of a material has a Clo value of (say)1.5, then 2 layers or twice the thickness of the same material will have a Clo of 3. However, the figure which is often misquoted as the Clo is in fact the Clo/oz/sq.yd - usually abbreviated to Clo/oz. A quick look at the table at the link quoted above will confirm that the Clo/oz figure for Climashield XP is a constant 0.77 for each of the different thicknesses shown.

To sum up, a Clo figure tells you how warm it will keep you. Clo/oz tells you how much weight you will have to carry for a given warmth, or lets you calculate what Clo value a particular thickness will give you (if you also know the weight in oz/sq.yd.of that thickness).

I am looking for a new synthetic bag (even considering quilts) as well. I am currently torn between the TNF Fission and the new Montbell U.L. Alpine Burrow. Both about the same temp rating and weight.

Other than those options you have a couple of bags from Sierra Designs and Mountain Hardwear. You also have the Marmot Pounder Plus, same weight as the Fission and Burrow, basically. The SD, MH and Marmot bags are supposed to be more like 40 degree bags whereas the Fission and Burrow are more like true 30 degree bags for most people.

If I come across anything else in your range, I'll let you know. One thing you may want to consider is that the Fission is $50 more than the Burrow. Is it $50 better?

Edwin, the Montbell U.L. Alpine Burrow #3 would also make my short list. Could could tell the the pros and cons of the Burrow vs. the Fission as you see them?

Also, the Pounder Plus received a EN 13537 lower limit rating of 36F. Another Primaloft bag, the TNF Orion, got a rating of 30F. My last years model weighs 2 lb., 5 oz.

Maybe I'm just out of date. The (2005) BPL book I own gives a slight advantage to Polarguard Delta over Primaloft PL1 due to a higher loft/weight ratio and durability. Durability aside (and other factors such as water retention and whether a scrim layer is needed) the book implies that Polarguard Delta is the best synthetic insulation around. Other reports suggest otherwise. If Climashield does have more clo per ounce (than both Primaloft and Polarguard) then that would explain some of the weight difference in the Fission vs. Cats Meow (TNF rates both as 20 degree bags). Some of the difference is caused by the different cut and may be caused by different shell material. Does anyone know if the clo numbers quoted on the other forum are accurate? Anyone know of any independent testing?

Edited by rossbleakney on 03/29/2007 22:27:10 MDT.

I am very impressed with the actual weight of the Climashield. I have made identical pieces, (insulated bottoms) of gear with the 1.8 ounce Primaloft Sport and the 2.5 ounce Climashield XP.
The Primaloft weighs 7.2 ounces while the Climashield weighs 6.8
The difference between the the 0.6" Primaloft and the .75" Climasheild is very noticeable as well.
I was warmer at 32* with the Cliamashield that I was with the Primaloft at 38*.

Ayce really loves me as I have gone crazy with winter projects, purchasing about $500 of stuff from thru-hiker.

After some disappointments, my only synthetic choice is the Climashield XP.
I'll have to say that I really like the Momentum fabric as well as I have gone through about 25 yards of it.

Alright,
I went ahead and sacrificed a 1' square perfectly even piece of the Climashield XP to weigh it.

It comes in right at 6.0 grams. Multiply by 9 and you get 1.9 ounces per yard.
Why it doesn't add up, I don't know.

Edited by awsorensen on 04/01/2007 14:26:35 MDT.

>>Some of the difference is caused by the different cut and may be caused by different shell material.

Ross, I think most of the difference is where you suggest. Last years' Cats Meow and Fission both had Delta insulation and the Fission was still significantly lighter.

I wouldn't take TNF's temperature ratings too seriously. The Cats Meow got a EN 13537 lower limit rating of 28F. I'm guessing that the Fission would be similar.

Ross, I just noticed that I was a contributor to the thread you linked to at the Backpacker forums back in October. I'll repost part of my original post here so that others can correct or comment on it.

"I've done a little checking around and have come up with this list of synthetic insulations, culled from several different sources.

Polarguard 3D, .63 clo/oz.
Polarguard Delta, .68 clo/oz.
Climashield HL, .68 clo/oz.
Primaloft Sport, .74 clo/oz.
Climashield XP .77 clo/oz.
Primaloft One .82 clo/oz.

If anyone can add to or correct this list please feel free."

Let me be the first to correct that post. The clo for Primaloft One should be .84 clo/oz. not .82 as I originally posted.

I have corrected a couple of your Clo numbers. My numbers came from a phone call to the sales rep today or the company web site.

Polarguard 3D, .63 clo/oz.

Polarguard Delta, .68 clo/oz.

This is an old number but I don't use this so didn't think to ask about it - Climashield HL, .68 clo/oz.

Primaloft Sport, .74 clo/oz.

Change - This number is current as of today. - Climashield XP .82 clo/oz.

Change - The company web site lists Primaloft One as .84 clo/oz.

Not listed - This number is current as of today. - Climashield Combat, .79 clo/oz.

Edited by bfornshell on 03/30/2007 19:01:14 MDT.

If anyone is interested, I am selling my brand new North Face Orion Sleeping bag. 20 deg. rating and filled with primaloft.

2 and a half pounds... not too bad. PM me if interested.

Thanks for that, Bill. I've drawn up a new list incorporating your changes and will edit it as we get new information.

Polarguard 3D, .63 clo/oz.
Polarguard Delta, .68 clo/oz.
Climashield HL, .68 clo/oz.
Primaloft Sport, .74 clo/oz.
Climashield Combat, .79 clo/oz.
Climashield XP, .82 clo/oz.
Primaloft One, .84 clo/oz.

Does anyone know what the Clo/oz is of primaloft one once is is prequilted like what Ayce sells? Ive bought some for a kit and am interested? Or is that .84 value for the prequilted material?

AYCE seems to know as much about clo as anyone around. And he's very helpful to everyone on the thru-hiker.com forums. I'll guessing that he could tell you.

I've been calculating this when I was choosing the best insulation for my quilt. With added weight of the scrim, I got 0.68 clo/oz. This neglects the effect of cold seams created by the quilting. It decreases the insulation value even more.

Dondo,

I went and tried out a last year's model Fission on the store this weekend. I don't have access to any Montbell products unless I order them.

In any event, here is what I see so far.

Fission -
Pros -
Vented/vaulted footbox
Heliolite ripstop nylon shell and nice lining
Warmth - very warm bag - heated up inside much faster than with other bags tried on like the Orion, Cat's Meow and a Mount. Hard. bag; don't know if this will translate to real world
Fill - the new Climashield is good stuff
Shoulder fit - plenty of room

Cons-

Knee/foot area tight (to me)
1/3 zipper might make it difficult to get cool in warmer weather (will the foot vent take care of that)
Price (higher than other similar bags, but seems like it's a get what you pay for thing here)


Montbell -

Pros -

Full zip
More compressible
Warmth (MB's temp ratings known to be fairly accurate)

Cons

Exceloft (an unknown to me but supposedly not as high of a clo/oz value as Climashield and also not as durable)
Will probably have to go to a long to get a good shoulder/knee fit.
Unknowns about the bag - shell construction/lining; never used MB prods before, but everyone raves about them.