Dumb luck? (I carry poncho tarp & down bag, no bivy)

I've been struggling with this math too.

I've been using an 8×10 Sil tarp at 13oz. I don't really need a bivy with it for rain because it's huge. Maybe a bug net, but we'll leave that off the table for now.

I got a 9oz 5×9 poncho tarp to save weight. When I set it up and got under it I quickly realized that I'd be in trouble with any blowing rain. I could pitch it to the ground but then I can't sit up. So I need to add a 7oz bivy? Now my shelter is 16oz.

Sure a poncho is dual use but I normally don't carry rain gear (I use a garbage bag or one of those $1 emergency ponchos) so I guess there is no real weight savings for me.

If I want to stay bivyless and save weight, maybe an 8×10 or 8×8 cuben tarp is the only reasonable upgrade?

I would agree, that it may be difficult to find a bivy/tarp that is lighter than just a bigger tarp, but where I see potential savings is:

bigger CF tarp
sleeping bag (no quilt because I toss and turn)
rain jacket
rain pants
bug netting (depending on area/season)
pack cover or trash compactor bag

vs.

MLD CF poncho/tarp (triples as pack cover)
ultralight bivy with mesh facial area
quilt (I can rock this because bivy helps w/ drafts, and not only quilt lighter by design, I've read a bivy adds degrees to quilt as well)
wind shirt
MLD Spectralite rain chaps

Thoughts?

I think your track- a bivy will add a few degrees to our bag (more than a few when windy)- also gives you bug protection and a ground cloth to boot

There is more to the equation than the absolute weight of the system (gasp!) You may not be happy if you save 3 oz by finding the lightest combination but sacrifice usability. All of the options you list would be right at home in a SUL gear list.

For instance, do you cowboy camp a lot? Then a bivy is really nice to have.

Do you enjoy using a quilt instead of a bag? Again, another vote for a bivy.

Does it rain a lot where you are or do you end up walking in high winds often? If so, then separate rain gear works better than a poncho.

Do you almost never use your rain gear and it stays in your bag 99% of the time? Then a poncho tarp will be fine.

Personally, I use a GG Spinnshelter which offers total rain protection without a bivy at around 10 oz. My rain coat weighs 6 oz. I don't bother bringing rain pants.

Andrew

I am in the NE, so rain is certainly not out of the question, but I'm just a weekend warrior for 3-4 day treks and if the weather looks horrible, my buds and I would prob bail. If there is a chance of rain, sure we're going, but if it's nasty, prob bail. I gotta read up more on bivys in terms of condensation and how comfy people that toss and turn in them are.

Andrew,
You're too right. I am shooting for SUL, and conditions matter. When we get in to these finite points I guess speaking in generalities clouds the conversation. I'm in Ohio, or lately more like the Olympic rain forest. Here the forecast for 9 months out of the year 50% chance of rain.

Also, I'm not really coming from an objective point of view. I generally dislike bivys. The forests on the east coast aren't that big compared to the west, which means it's really easy to bail. Knowing this makes it easier to push a minimal setup.

I'm putting a lot of thought in to this as I am trying to piece together a new shelter system for above 50F, 50% chance of rain. A summer rig if you will. The two heaviest things in my pack are my tarp and my bag. Makes sense to go after the big 13oz sil tarp because I am really happy with my MB Down #3 bag.

So, one of the things I am kicking around is a Six Moons Gatewood. Or an 8×8 cuben tarp. The cuben tarp would be killer but also 2x the price. I'm not sure I have added anything to the conversation except that if you get the right shelter you can forego the bivy. And any input would be nice.

@Daniel: If you like your current system, why not go for something like a Spinntwinn? Way cheaper than a cuben tarp and you would save ~4 oz and still wouldn't need a bivy.

For me, a poncho is like a space blanket- something I hope I don't have to use, but pack just in case. If I know it's going to rain, I'd much rather have real rain gear and a decent size tarp to hide under.

Andrew

The trouble with the whole tarp/bivy/bugnet vs tent and poncho/bivy vs tent/raingear thing is that you have to reproduce all the pieces to get the same thing and this seems to make the weights so close to each other that it really just becomes a matter of preference rather than purely a matter of weight reduction. Oh I'm sure you can do some math and find one or the other is always heavier, but it's usually heavier by a couple of poptarts.

I've decided that instead of weight, I choose one or the other based on what I feel like experiencing for a given trip.

I personally dig the poncho/tarp thing, so now I'm researching:

cueben fiber quilts….

How do people react under a vapor barrier like that for comfort?

Are they waterproof/resistant enough to double as a dwr bivy to provide side rain protection on such a small poncho/tarp?

Can the quilt be made big enough for me tossing and turning to stop drafts
(because if I can't stop drafts, then I need to add the weight of a bivy)

If I go for the CF quilt and no bivy, then I need to account for adding in weight of a bug net during certain times of the year.

I had been comparing different gear/shelter configurations here:

http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/47350/index.html

Trying to consider the pros and cons and the overall weight effect, not just one shelter vs. another.

Well today I went for the left most option in my spreadsheet, a tarp tent of sorts w/ bug netting that affords me much better rain coverage:

http://www.bearpawwd.com/tents_tarps/cubden.html

In the NE we have bugs so I'll appreciate the large bug-free space more often than not and this shelter will afford me better rain protection and sprawl out space with my quilt. Expect a BPL review when I receive it, I'm psyched!

I appreciate everyone's input….I only have one last question about the Jacks R Better quilt being worn as an insulating layer:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=47374

Thanks again, and if anyone is looking to hike in the NE, let me know!
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=47233

I don't know what it's like to sleep in a waterproof sleeping bag, but I often wear my rain pants and jacket to bed and find it very warm and comfortable. I'm always looking not just for sleep but for warmth-induced coma.

Yeah, I suppose I am "that guy" on the trail sweating away, including in bed. I guess just not for me. Least this time around with my gear re-vamp. :p