Bivvi bags - advice please

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SA_SA_SA
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Re: Bivvi bags - advice please

Postby SA_SA_SA » 8 Mar 2020, 7:57pm

Isn' t the flaw in bivy bags when you are in you wet waterproofs (and it may still be raining) and want to get into a nice dry sleeping bag (without instantly making it a wet one...):

once TGO had a review of bivi bags and one interesting 'one' was a nordic miltary one:

it was less a bivi , more a long waterproof cagoule (with arms) but its hem could be unfolded to cover ones feet when lay down to sleep (feet downhill presumably): presumably any extra sleep insulation jacket/gilet/blanket was waterproof and worn/laid over top....?
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pjclinch
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Re: Bivvi bags - advice please

Postby pjclinch » 9 Mar 2020, 12:36pm

SA_SA_SA wrote:Isn' t the flaw in bivy bags when you are in you wet waterproofs (and it may still be raining) and want to get into a nice dry sleeping bag (without instantly making it a wet one...):


Same basic issue as a keeping the inner of a tent dry if there's no porch to speak of.
Exec. summary is that the more you're looking at set-in rain the less fun you'll have in a bivvi, but there again the less fun you'll have on a cycle tour. Particularly with single overnights one can tune use according to the weather forecast, and if it goes wrong it's only one night of misery.

SA_SA_SA wrote:once TGO had a review of bivi bags and one interesting 'one' was a nordic miltary one:

it was less a bivi , more a long waterproof cagoule (with arms) but its hem could be unfolded to cover ones feet when lay down to sleep (feet downhill presumably): presumably any extra sleep insulation jacket/gilet/blanket was waterproof and worn/laid over top....?


The Hilleberg Bivanorak, perhaps?

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mattheus
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Re: Bivvi bags - advice please

Postby mattheus » 9 Mar 2020, 12:57pm

pjclinch wrote:
SA_SA_SA wrote:Isn' t the flaw in bivy bags when you are in you wet waterproofs (and it may still be raining) and want to get into a nice dry sleeping bag (without instantly making it a wet one...):


Same basic issue as a keeping the inner of a tent dry if there's no porch to speak of.
Exec. summary is that the more you're looking at set-in rain the less fun you'll have in a bivvi, but there again the less fun you'll have on a cycle tour. Particularly with single overnights one can tune use according to the weather forecast, and if it goes wrong it's only one night of misery.


Exactly.

The Book of The Bivvy man is clear to say that during any really sustained wet-weather on a trip, he'll accept deviating into a dry building maybe every 3rd night. If i was camping in those conditions I'd enjoy using a YH/hotel to dry everything out after a few days!

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NATURAL ANKLING
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Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 9 Mar 2020, 8:03pm

Hi,
I am still toying with a lightweight shelter to use on a UK tour in the summer.
Meanwhile I have bought a cheap double hooped bivvy :)
Its in the country so should see it soon.
I will camp out in garden to test it :P

It might be complete disaster......................report soon.
Not really happy with over 1KG stuff, so if this does not measure up its back to the drawing board (home made) or dig very deep for something expensive.
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LinusR
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Re: Bivvi bags - advice please

Postby LinusR » 2 Aug 2020, 11:32pm

LinusR wrote:I'm thinking about a bivvy weighing less than half a kilo (perhaps this one https://www.mountainwarehouse.com/bivy-bag-p13634.aspx/khaki/).


Just a quick update on this since my original post. Obviously things changed since early March and so did my travel plans. I eventually went with the above bivvy bag (on offer for £16.99) from my local branch of MW. I spent the last three nights sleeping on the south coast beach in Hampshire, no tarp, and a 1/2 season bag (SnugPak Microlight from 23 years ago) with an Ajungilak pertex liner. I also treated myself to a Thermarest NeoAir Uberlite https://www.cotswoldoutdoor.com/p/therm-a-rest-neoair-uberlite-sleeping-mat-D2424414.html (183cm long) which I placed inside the bivvy bag. This worked out pretty well. It was all a bit of a snug fit inside the bag (I'm 186cm and 80kg) but no condensation at all. The air temperature was between 14 and 16C. The larger Thermarest would have been too big inside the MW bivvy, as would a thicker sleeping bag. A few degrees colder and I would have been too cold due to the sea breeze. The key to comfort was getting the Thermarest inflated just right so that it gave just enough support without me wobbling off it. I also bought a Thermarest pillow (£25) which helped with comfort.

I may give it another go with an older but wider Thermatest which would have to go underneath the bivvy rather than inside it as it would be too wide and is rectangular rather than mummy-shaped. I'll be looking to get a small tarp next as I have a night in the woods planned.
Last edited by LinusR on 10 Sep 2020, 9:40am, edited 3 times in total.

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NATURAL ANKLING
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Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 3 Aug 2020, 12:50am

Hi,
Only used a bivy bag a few times and it was not raining on me, cheap and nasty but no condensation.
No condensation normally means you are warmer for sure, sa this is my experience with waterproof jackets breathable.

You seen the vid posted on the "GBDURO" post that I posted, the guy goes into great detail with his gear......and so much gear......custom made too :P
Bivy and mat look very high tech due to their size?

And I thought I took a lot of gear.........his tool kit looks small :)
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Sweep
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Re: Bivvi bags - advice please

Postby Sweep » 3 Aug 2020, 8:39am

Many thanks for the update linus.
That bivi maybe a bit small for me as I like to stuff everything inside the bag.
So will have to stick with my somewhat bulky ex army bag for now.
It's definitely a good price though.
Interesting that in your entire trip you experienced no significant condensation issues.
According to some reviews on the MW site, some seem to have.
Can you account for this?
Sweep

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NATURAL ANKLING
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Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 3 Aug 2020, 8:43am

Hi,
LinusR, I followed your link to the website and it said it's waterproof with taped seams but does not mention it is breathable?
That's an original price of £40 I would imagine it is breathable?
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LinusR
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Re: Bivvi bags - advice please

Postby LinusR » 3 Aug 2020, 9:26am

Actually, zero condensation over three nights out. I was sleeping on a shingle beach less than 50 metres from the sea and there was a gentle breeze all the time. I didn't seal the bivvy bag but left a large opening for my breath to escape, just covering my head with the sleeping bag and liner. Bivvy was bone dry each morning. Plenty of air passing over, warm night, and no dew settling; probably ideal conditions for keeping dry. I had originally intended to get the Hunka XL but it was only available in bright red - not ideal for stealth camping. The khaki MW bag, however, is the right colour and it is very lightweight and incredibly cheap. And despite it being very thin it is pretty tough and protected the delicate Thermarest Uberlight matt. It is just a bit cramped in the width for someone my size, albeit with the 64mm thick mattress inside it.

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LinusR
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Re: Bivvi bags - advice please

Postby LinusR » 3 Aug 2020, 9:35am

Sweep wrote:Interesting that in your entire trip you experienced no significant condensation issues.
According to some reviews on the MW site, some seem to have.
Can you account for this?


I noticed the reviews about condensation but I thought I'd take a chance at that price. I can only think it was a combination of layers (Pertex liner and sleeping bag) and ideal conditions including the air passing across shingle underneath. Might be very different under a tarp in a hot thunderstorm on compacted grass and earth!

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pjclinch
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Re: Bivvi bags - advice please

Postby pjclinch » 4 Aug 2020, 8:06am

Condensation is mostly about the weather you happen to have at the time.

On a camping trip on the Black Isle once we had two nights in succession where ambient temperature was about the same both nights, wind changed from light to none and, presumably, humidity went up a lot. The first night there was practically no condensation in the tent and no dew, next was as heavy a dew as I've ever seen and the inside of the fly was literally dripping from end to end.

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Sweep
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Re: Bivvi bags - advice please

Postby Sweep » 4 Aug 2020, 9:12am

NATURAL ANKLING wrote:Hi,
I am still toying with a lightweight shelter to use on a UK tour in the summer.
Meanwhile I have bought a cheap double hooped bivvy :)
Its in the country so should see it soon.
I will camp out in garden to test it :P

It might be complete disaster......................report soon.
Not really happy with over 1KG stuff, so if this does not measure up its back to the drawing board (home made) or dig very deep for something expensive.

What was this?
Did you post an update in a another thread?
Sweep

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NATURAL ANKLING
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Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 4 Aug 2020, 10:09am

Hi,
Sweep wrote:
NATURAL ANKLING wrote:Hi,
I am still toying with a lightweight shelter to use on a UK tour in the summer.
Meanwhile I have bought a cheap double hooped bivvy :)
Its in the country so should see it soon.
I will camp out in garden to test it :P

It might be complete disaster......................report soon.
Not really happy with over 1KG stuff, so if this does not measure up its back to the drawing board (home made) or dig very deep for something expensive.

What was this?
Did you post an update in a another thread?

viewtopic.php?f=42&t=136340
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Re: Bivvi bags - advice please

Postby LinusR » 19 Aug 2020, 10:58am

IMG_20200819_101721945.jpg


Another quick update on the bivvi. I've now got hold of a small tarp to complete the sleep system.

Pictured from left to right is:
Snugpak Microlight sleeping bag; about 850g
Mountain Warehouse Bivvi bag; about 350g
Snugpak Stasha G2 tarp; https://www.outdoorgb.com/p/Snugpak_Stasha_G2_Tarp_Shelter/ 450g
Thermarest Neoair Uberlite. about 350g

Not pictured is the Thermarest pillow, about 300g (packs down to about the same size as the sleeping bag).

Using the tarp and bivvy is about half the weight of my Saunders Jetpacker tent.

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NATURAL ANKLING
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Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 19 Aug 2020, 12:11pm

Hi,
My super lightweight set up consist of a sleeping bag 525 g, Centre zip So can be used as a quilt / Quick cover for a snooze.
3/4 or full length zip is important here.
Comes with an midge net.
Sleep mat 4mm foam (Surprisingly comfortable on a concrete floor) just a pound from the pound shop although they sell for more than that now 50 times 180 cm approximately, 100 g.
Cheap Gelert bivvy bag 330 g approximately, Cost something over 20 quid.
Home-made fleece pillow case 70 g you just stuff with your clothes for a pillow.
Comes out in about an ounce over a kilo.
When I went round on my coast ride Devon and Cornwall I took a waterproof hat type banaclava thing, did not have to use it but it might come in handy if I do stay outside in the bivvy bag.
Considering a small type of tarp To cover your head area.
NA Thinks Just End 2 End Return + Bivvy
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.