CF bathtub ground sheet vs bivy (plus hot weather sleep considerations)

[Rmcpeak]

Over the winter I acquired a zpacks cf bathtub and pocket tarp. Total weight for that configuration is like 10 oz. I haven't used it yet. Will probably test it on a 60 miler in mid-April. But man, it sure would be nice to have a bivy, right? And lo and behold the Rolls Royce of bivies (in my size no less) is on EBAY right now -- yes that one! The CF eVENT one.

Related: my 40 deg APEX EE quilt is too warm for high summer, when I do my big Lashes, so I'm searching for something lighter but don't think it makes sense to by a 50 degree quilt.

Could the bivy be my hot weather "blanket?"

Is the CF bathtub just as good or even better than the bivy? Maybe because it is lighter and more breathable (obviously)?

HELP!

Talk me into, or out of something! Only other CF addict SULers can possibly understand this.

[cmoulder]

Bugs. Get a Borah bug bivy. The 40° Rev Apex (formerly Prodigy, 17.7 oz) will be fine... stick a leg or 2 out. And take a 4' x 8' sheet of polycryo .7 mil for mud.

[Rmcpeak]

I'll check it out but bugs have not been a huge problem for me in 600 miles of 3 season AT hiking. I hit a little Deet as needed and I think I might have treated my quilt in Permethrin.

[cmoulder]

Then it's even easier... skip the bivy and keep the polycryo or use the CF bathtub you already have with the Rev Apex. I also have a Rev 50 downtek that weighs 11.3 oz but synthetic is much better if you get a cool rain.

Could the bivy be my hot weather "blanket?"

No. Unless you're carrying enough total clothing insulation to equal a quilt, which isn't likely. And a CF/eVent bivy is going to be relatively heavy (funny to actually write that, lol.)

[Slo-go'en]

Even though the bivy can "breath", your going to get really clammy in it when it's hot and humid out. And it still gets a little chilly early in the morning. I may go to sleep using just a liner for a blanket, but at some point I'm pulling my bag over me.

Does the bathtub also have netting? If so, bathtub and tarp is the way to go, you need ventilation. If it's just a fancy ground cloth and tarp, bugs could be an issue. I'd want to have full netting to keep the bugs out.

The CF bivy would be more useful in the shoulder seasons when you could use a little extra weather protection and warmth and bugs are less of a problem.

[cmoulder]

Bugs always figure large in my calculations, as well, but some lucky folks don't seem to have problems with them.

[Dogwood]

For summer with a bathtub CF Solo size I'd go with a more breathable WR bivy than an eVent WP bivy. If really wet conditions are anticipated to exist on your Lashes especially when lean-to's aren't a desired or available option I'd go with a larger coverage tarp of heavier wt cuben. IMHO, the Pocket Tarp is a just in case shelter not a regular go to several wk shelter option AND NOT under stressful conditions/weather... high winds, torrential persistent rain, exposed locations, abrasive sites, bushwacking CS's... BUT, yes I know how we can get gram weenie starstruck but be careful to match the shelter with the conditions...in my respectful opinion.

As Joe says, "The material is strong enough for an occasional use shelter, but may not be the best choice for every day use, such as a thru-hike."

"Is the CF bathtub just as good or even better than the bivy? Maybe because it is lighter and more breathable (obviously)?"

NO! But it depends the context of your situations. A bivy is NOT just a shelter component element. It is also a sleeping system component element. It sounded initially like you were aware of this.

You could try a WR more breathable bivy in the 4.5-5.5 oz range paired with a 4 oz or so silk ripstop liner with Lycra stretch side panels and a light wt polycro groundsheet rather than the 3.2 oz ZP CF Solo bathtub groundsheet.

OR, you could go with that CF bottom eVent bivy, a 4 0z silk liner, for summer above 50*, or maybe even just appropriate sleep wear, FOR SUMMER TIME AT WEATHER, and no groundsheet which MAY be you lightest wt option. IMHO, if I was to have any rain in the forecast, which really would be what I was expecting if being a gram weenie carrying any size tarp, I'd want a groundsheet with the ZP Pocket tarp.

[Rmcpeak]

4 0z silk liner, for summer above 50*

These last few comments are VERY helpful. Got me thinking about adding a bug net to the floor... that would be neat. What 4 oz silk liner do you like?

Thank you, thank you! I'm over the $350 CF eVENT bivy idea! Shew, close call!

[Dogwood]

https://www.rei.com/product/866777/s...ch-mummy-liner

[cmoulder]

When you look at the weight of a tarp/bivy or tarp/tub (or groundsheet) setup, the simplicity of a Solplex starts looking quite attractive... 'one and done' and quite stormworthy.

[Rmcpeak]

When you look at the weight of a tarp/bivy or tarp/tub (or groundsheet) setup, the simplicity of a Solplex starts looking quite attractive... 'one and done' and quite stormworthy.

I have a SMD Skyscape Trekker (nylon not Cuben), but on my 150 miler last summer I carried it and used it only 2 nights out of 5 -- slept in shelters a lot. My thinking is that the groundsheet/tarp combo is ligher (by almost a pound I think) gives me more options and is multi-purpose. The tarp (or groundsheet for that matter) could be rigged as heavy downpour rain gear (I carry only a Houdini in Summer). The groundsheet could allow for cowboy camping if the mood/weather was right. I can also use the groundsheet INSIDE of a shelter if it isn't packed full and if its really filthy or something. The bathtub might keep creepy/crawlies/mice out of my face at night...

Is my thinking sound?

[cmoulder]

The Solplex weighs about 18 oz with guylines and stakes (depending upon which ones are used), which is hard to beat although it will put a serious dent in the wallet, for sure.

I'm only cowboy camping if there are no bugs, and for that a simple 1.5 oz sheet of .7mil polycryo suffices as a ground sheet. I don't do shelters. I have a Duplex (all-up weight about 22 oz) that is nearly always the best choice for me (and my pooch).

But if you can rack up 150 miles in 6 days you almost certainly know more about this stuff than I do!

[Rmcpeak]

Yeah, I don't "camp" -- I crash for a few hours. Shelters can work well for that, but I've got to be prepared for either a full shelter or a party scene/belligerent drunk hanging around. Not to mention it's an "essential" to have shelter and stupid to go out on an overnight without something to keep rain or scorching sun off in a pinch. I don't worry about cold in regard to this particular gear question -- I have a cold weather kit that includes a tent. This is my summer kit I'm talking about which I've got down to a bw of about 5 lbs.

That is the key to hiking 150 miles in 6 days. Go as light as possible and just walk from dawn til dusk (or later).

[Slo-go'en]

I also have a Trekker. If I were to replace it, I'd get the Solplex, but to spend $555 to save 8 oz doesn't seem cost effective to me. But then, I'm not aiming for a 5 lb BW either. I'd be happy with 10 and settle for 15

[Rmcpeak]

I also have a Trekker. If I were to replace it, I'd get the Solplex, but to spend $555 to save 8 oz doesn't seem cost effective to me. But then, I'm not aiming for a 5 lb BW either. I'd be happy with 10 and settle for 15

Yeah, I guess I'm moving to tarp/groundcloth because the tent isn't multi-purpose. I've come to despise carrying anything that isn't getting used a lot (other than emergency meds/fire/FA kit). I've gone stoveless too.

[cmoulder]

OK....

Borah bug bivy, Zpack pocket tarp, polycryo ground sheet. Total weight about 12 oz and lots of flexibility. I could almost talk myself into that.

[backtrack213]

good summer quilt is the MLD FKT quilt rated between 55-35 depending on clothing you wear while sleeping in it. Good summer option in my opinion.

[JC13]

good summer quilt is the MLD FKT quilt rated between 55-35 depending on clothing you wear while sleeping in it. Good summer option in my opinion.

The downside to that is he could grab another EE with APEX instead of down and be at 11.79 oz and $165 for a Large compared to the FKT at 16 oz and $230.

If you truly just want a cover/sheet, look at the DutchWare quilt liner. 2.5 oz $50, easy enough to supplement for temp with your other gear.

https://dutchwaregear.com/quilt-liner.html

[Rmcpeak]

The downside to that is he could grab another EE with APEX instead of down and be at 11.79 oz and $165 for a Large compared to the FKT at 16 oz and $230.

If you truly just want a cover/sheet, look at the DutchWare quilt liner. 2.5 oz $50, easy enough to supplement for temp with your other gear.

https://dutchwaregear.com/quilt-liner.html

I agree no point in down for summer quilt. I've got a S2S silk mummy liner on way... will experiment with that. The Dutchware liner could be a good option... Thanks!

[Slo-go'en]

I've also got the Gatewood cape and serenity net, which is a decent multifunctional set up at reasonably low weight and volume, but the cape kind of sucks as rain gear and is too cramped as a shelter. After using that set up through PA last spring, I sent it home and got my real tent and rain jacket for the rest of the hike. But it's not too bad an option for a week long summer hike when you don't expect to use it much.