I'm planning on thru-hiking the Sierra High Route starting mid-July this year.

When it comes to my sleep system, I've got a couple of pieces nailed down:

* My sister is custom making me a tarp I designed (silnylon w/ beaks. Similar to the RayWay design, but tapered on the sides with non-symmetrical beaks). This will only get used during bad weather

Here are pics of a model I built of the tarp:






Fabric dimensions and some details:


* Titanium Goat Raven Bivy w/ full net hood - Haven't purchased yet, but this looks like a great option. I'll probably take along a Tyvek groundcloth to protect it from rocks too (sleeping pad will be inside bivy)

* NeoAir XLite Women's sleeping pad - This pad seems to have the best ratio to weight/r value for an inflatable pad. Small enough to fit comfortably in the bivy too.

Here's the question. I'm unsure as to which specific sleeping bag to get. I know I want down and it also has to be light and have continuous baffles. I'm 6'3" 175# and I tend to sleep very warm. I'm tempted to get a 20deg bag, but I don't want to overheat when I sleep at lower elevation or if I use the bag on other trips. I'd rather be slightly on the cold side than be on the hot side. Should I go with a 32deg bag instead, or am I sacrificing a lot of comfort there on colder nights? I could always bring a liner on cold trips to offset the warmer rating, right?

Here are some bags I'm considering:
* Marmot Helium +15 - Seems like a great bag, but I really think I'd overheat in it.
* Western Mountaineering Ultralite - Also seems like an awesome bag, but too warm?
* REI Igneo +19 - With REI's 20% off the price is right, but I think the WP fabric might provide a moisture issue. Also, I don't think the bag has continuous baffles
* Western Mountaineering Megalite +30 - Seems great, but doesn't look very warm. Looks might be deceiving, though.
* Marmot Hydrogen +30 - Good option?
* Montbell SpiralHugger +30 - How's the hood on this? Will the stretchiness break down over time? I want this to last me 10-20 years.

Thoughts?

Edited by thenerb on 03/23/2012 10:08:24 MDT.

I have a WM Megalite with 2 oz overfill. I love the extra girth. It went down to 19F last weekend and I was not cold at all using a Neoair and CCM combo, it snowed 1 foot that night.

I would definitely go with 30 degree bag or warmer. In the high Rockies at the height of summer I use a 40 degree quilt. It's plenty. A light down sweater or Nano Puff is enough extra insulation if conditions get much below 40 which is rare in July even above treeline.

There are two paths to adjust warmth… one if do a lighter bag and use something to supplement it's warmth when necessary. Generally I don't recommend using a liner for this because liners provide less warmth / weight than other options and aren't versatile. You are better off bring some high loft clothing which you can sleep in or wear in camp before going to bed, and makes a good pillow when you don't need the warmth.

The second option is to make your bag less warm. Shift the down to below rather than above you, unzip it a bit, or unzip it a lot and use it like a quilt.

I am someone who sleeps warm. For me, a 30F quilt has been a good compromise. Quilt + all clothing lets me sleep reasonably comfortably down to around 15F, but it's easy for me to ventilate in warmer conditions. Of the bags you have listed, they are all good options. There is also the WM Summerlite and bags from Feathered Friends. I would recommend figuring out what girth is good for you. I don't know what you experience will be, but for me 1-2" makes a huge difference. The 59" of many of the WM bags make me feel like I am in a strait jacket, the 64" of the Megalite seems huge… the 62" of my Versalite (use during winter) and the marmot bags are just right for a bag.

--Mark

I went through a similar debate on bags for the Sierras. I'm 6'2" and found the RAB Neutrino 200 combined with a Montbell UL jacket to be the best solution. The Neutrino 200 is a 35 degree bag which is great for summer in the Sierras. The Montbell is my warmth layer and works well in mornings and evenings as well as gives me a comfort margin if the night time temps drop below the thirties.

Note, the RAB bags are one size and cut about the same as a long bag fitting up to 6' 4". I'm 6'2" 200lbs, so the fit works well. There is definitely extra room for someone 6'3".

You might consider a down quilt from a cottage builder, like Enlightened or Zpacks.

As for warmth, if you're using very high quality down (850-900FP), then it is much more logical to add a few ounces of down to a quilt/bag, rather than bringing/wearing extra/heavier non-loft clothing to bed in order achieve a lower effective temperature rating.

Here's some basic math:
- typical 80"X50" (avg taper from 54 to 44) quilt = 4,000 sq in
- 2" loft for a 32 degree bag = 8,000 cu in
- divide by 900FP = 8.9-9oz
- add 35% overfill (3oz) to take loft to 2.6"+, good for 25 degrees

If you use something like M50, then 8,000 sq in of material (shell & liner) weighs around 5-6oz. Add 12oz of down, and you have a 17-18 ounce, 25 degree quilt.

As for your tarp, it looks like Shires' original plan. I'm a believer in making a tarp bigger rather than bringing a bivy. Again, there is less material in making the tarp larger than creating another separate item. Besides, it's a lot easier & lighter to bring window shrink wrap as a GC vs something heavier (even 1.3 sil) sewn to the bottom of the bivy.

Last, but not least, both M50 & M90 have very good DWR, which means you can cowboy camp unless it looks like it's gonna rain. With a 25-30 degree quilt/bag, you also don't need a bivy to add any incremental warm for a typical Sierra summer evening.

Edited by Hobbesatronic on 03/23/2012 11:14:33 MDT.

Hmm. Here is a budget friendly option. Rab Neutrino SL 200. Down on the top and synthetic on the bottom. Doesn't tick all the boxes, but at $169, the price is pretty good. I would be using this with an inflatable pad with an R value of 3.9, so it might be an option.

http://www.campsaver.com/neutrino-sl-sleeping-bag-800-down

Would I be better off just spending the cash and getting a full down bag?

Thoughts?