Dr Jordan’s SUL Arc Custom

[Jason Shaffer]

From the SUL article: “My sleeping bag choice is a custom 15.2-ounce Arc Alpinist X with a Pertex Quantum shell with 800+ fill down offering 2.25 inches of single layer loft that tapers to 7 inches of (single layer) loft in the footbox.”

Could you please offer some more info on this bag? Do you recall what shoulder and footbox measurements you specified, for a bag that lofty to weigh in so light? The Ghost in Quantum, size med is 16 oz, w/ what I assume is a uniform 2″ loft!

I’m trying to decide on specs for my own custom nunatak, and you and I are similar build. I’d need enough space to wear cocoon p/over and occassionally cocoon pants, however. Any advice much appreciated!
-Jason

[Bob Gabbart]

Nunatak USA now sell’s Ryan’s design as the Arc Custom. If you ask for that you will get the same thing he describes in the article.

[Jason Shaffer]

I guess that was my question, in part. The specs I’ve seen for Nunatak’s ‘Arc Special’ don’t make it totally clear regarding the tapered loft. Either does BPL’s page for the BMW Arc X — it states a baffle height of 2″. Is this really the same bag?
-Jason

[jacob thompson]

maybe he is using some of nunataks special hand picked 950+ down.

[Jason Shaffer]

Bob – there is no ‘Arc Custom’ on Nunatak’s site. That’s just a generic term for any custom version of an arc bag. You must be thinking of the Arc Special X, which I reference above. You are right that this is BMW’s Arc X. But if it is the same as what the excerpt above describes, the specs are not published quite the same.
Jacob – article published Aug 03, pre-Eider and all.

As I recall from reading this article 2 yrs ago, BMW’s own Arc X was still new enough that the bag in the article could just have easily been one of a few different prototype designs experimented with before the final Arc X specs were decided upon.

Hence my hesitance to just assume these bags are the same. I might be over-analyzing, but I was really hoping for a definitive answer.

[Mike Storesund]

In the Arc FAQ section on the Nunatak site it has a Q&A:

Q – I have heard about a quilt called the Arc X. It looks very similar to the Arc Alpinist. What’s going on?
A – It is no coincidence that it look similar to our Arc Alpinist. Nunatak manufactures the Arc X bag for a company called Bozeman Mountain Works (BMW) in Pertex Quantum fabric. We simply changed the fill amount (put in less) and switched fabric (to the slightly heavier Quantum) to produce a bag to BMW’s exact specifications.

[Jason Shaffer]

Hi Mike,
Yes, I saw that in the FAQ. Thanks tho. I guess I’ve not been very clear in my explanations. I knew that Nunatak’s Arc Special X is the same as BMW’s Arc X. What threw me off was the part about ‘2.25 inches of loft tapering to 7 inches’. I’d not seen that published specifically in regards to any Arc bag. They simply say, for instance, 2″ baffle height.

But I just came across this, buried at the very bottom of the (now defunct) BMW Arc X page:
“the bag is 4+ inches thick (double layer) at the shoulders and tapers to 7″ of loft in the footbox. The continuous baffles allow you to distribute down to the top to give you an effective single layer loft of 2.5 inches.”

TA-DAAAA! That’s actually the info I was groping for. Was not aware of effective loft vs. baffle-height/stated loft. Confusion resolved. Thanks all.
-J

[Jason Shaffer]

Also, in the BMW Arc X User Notes, the footbox loft is stated as 7″ DOUBLE thickness, not single as per SUL article. A slight inconsistency, which added immensely to my confusion. :^0

[Bob Gabbart]

This web page:

http://www.nunatakusa.com/nunatak_gear_etc.html

Used to reference the “Arc Special.” However, it no longer talks about it. If you do a search in the forums here on this website, you will find people talking about it. Basically, the “Arc Special” and the “Arc X” are the same thing. I bought one a couple months ago. I also made sure that, yes, it does use the same fill chart (with less fill in the chest). It’s basically an Arc Alpinist made out of Quantum with a different fill chart.

Bob

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