Bivvi bags - advice please

Specifically for cycle touring subjects & questions
User avatar
Sweep
Posts: 6501
Joined: 20 Oct 2011, 4:57pm
Location: London

Re: Bivvi bags - advice please

Postby Sweep » 19 Aug 2020, 4:03pm

thanks for update linus - would be interested in hearing about the snugpak tarp in use - I like snugpak stuff.
Sweep

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 9 Sep 2020, 9:39pm

Sweep wrote:thanks for update linus - would be interested in hearing about the snugpak tarp in use - I like snugpak stuff.


First outing with the Snugpak Tarp. Not much of a test as the night was dry, warm and still. The tarp is well-made and has some press studs so it can be used as a bivvi. I set it up as a lean-to shelter with two tent pegs (not included with the tarp) on the ground and two paracords (included with tarp) to two trees.
IMG_20200908_184817322.jpg


I was again using the Mountain Warehouse bivvi bag with the same Thermarest and same Snugpak sleeping bag. Despite a warm and humid night, there was no condensation on the bivvi bag and my sleeping bag was dry. Again I slept with my mouth and nose poking out of the bivvy.

After four nights using the bivvy and Thermarest Uberlite I think both may be a little small for me because of the way I sleep. The width of the Thermarest and the bivvi is quite restricting as I'm tall (6' 1" 186cm). Next time I'll try the Thermarest under the bivvi bag but on top of some light groundsheet and see how that goes.

User avatar
NATURAL ANKLING
Posts: 12094
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 10 Sep 2020, 11:38am

Hi,
This is the major problem with bivvy bags is that they are made just so like most sleeping bags, you might be to fit them that you can't move around much without a bit of a tangle.
Bivvy bags should be made big enough to take a reasonable size winter sleeping bag for least someone who is 6 foot plus.
I did see some overlarge bivvy bags at one point but I can't find them any more.
As per usual the lighter that can make them the more attractive they will appear on the surface.
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.

mercalia
Posts: 14005
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Bivvi bags - advice please

Postby mercalia » 10 Sep 2020, 1:24pm

LinusR wrote:
Sweep wrote:thanks for update linus - would be interested in hearing about the snugpak tarp in use - I like snugpak stuff.


First outing with the Snugpak Tarp. Not much of a test as the night was dry, warm and still. The tarp is well-made and has some press studs so it can be used as a bivvi. I set it up as a lean-to shelter with two tent pegs (not included with the tarp) on the ground and two paracords (included with tarp) to two trees. Image

I was again using the Mountain Warehouse bivvi bag with the same Thermarest and same Snugpak sleeping bag. Despite a warm and humid night, there was no condensation on the bivvi bag and my sleeping bag was dry. Again I slept with my mouth and nose poking out of the bivvy.

After four nights using the bivvy and Thermarest Uberlite I think both may be a little small for me because of the way I sleep. The width of the Thermarest and the bivvi is quite restricting as I'm tall (6' 1" 186cm). Next time I'll try the Thermarest under the bivvi bag but on top of some light groundsheet and see how that goes.


what is the stockade for? to keep the critters at bay? I think the brighter ones may just go around the side to have a nibble :wink:

User avatar
Sweep
Posts: 6501
Joined: 20 Oct 2011, 4:57pm
Location: London

Re: Bivvi bags - advice please

Postby Sweep » 10 Sep 2020, 3:49pm

Thanks for the update Linus.
I did check out the Mountain Warehouse bivvy a couple of weeks ago - at a very good price if not as good as yours.
Am impressed by your reports on its breathability but I think I will stick with my army goretex thing, even if that is not immune to condensation.
It's a fair bit bigger than the MH one and I like to put my sleeping mat inside it - with a groundsheet between the bivi and the ground.
Still don't understand that way of tarp pitching by the way - I prefer to be sheltered from both sides and yet to stlll have 360degree visibility for watching the wood and nature/spotting invaders.
Sweep

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 10 Sep 2020, 6:27pm

mercalia wrote:
what is the stockade for? to keep the critters at bay? I think the brighter ones may just go around the side to have a nibble :wink:


You can't be too careful! I've got trip wires (not visible) covering the other sides. :D

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 10 Sep 2020, 7:34pm

Sweep wrote:Thanks for the update Linus.
I did check out the Mountain Warehouse bivvy a couple of weeks ago - at a very good price if not as good as yours.
Am impressed by your reports on its breathability but I think I will stick with my army goretex thing, even if that is not immune to condensation.
It's a fair bit bigger than the MH one and I like to put my sleeping mat inside it - with a groundsheet between the bivi and the ground.
Still don't understand that way of tarp pitching by the way - I prefer to be sheltered from both sides and yet to stlll have 360degree visibility for watching the wood and nature/spotting invaders.


The tarp did protect me from the stuff falling off the trees in the night so it's a useful pitch method in that respect.

The MW Bivvy (not available at the moment) is identical in size to the regular sized Hunka https://alpkit.com/collections/bivvy-bags/products/hunka. It is slightly wider and longer than my Snugpak sleeping bag (zipped up). So the two are a good match - without the mat; so that's gonna have to go outside with a groundsheet. I'll be testing it with the mat outside this weekend when I sleep on the beach on the south coast. I'll be doing more experimenting with tarp pitching.

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 16 Sep 2020, 7:06pm

Another three nights spent in the bivvi, so a brief update. This time I put the Thermarest Neoair Uberlite matt under my bivvi bag (and on top of a ground sheet) to give me more room inside the bivvi. It was much more comfortable this way. A big improvement. Sunday night into Monday morning a heavy dew settled (Hampshire south coast 13-14 September) and I woke up in the early hours feeling cold. The MW bivvi bag was covered in dew and there was condensation on the inside of the bag which chilled my sleeping bag and caused me to feel cold even though the air temperature was about 15 degrees C. At sunlight I noticed that everything was wet - bike frame, shingle, all covered in water droplets. If I had the tarp this probably could have been avoided.

Second night it was again very warm but no dew fell. Everything was as dry as a bone, even though I was slightly too hot at times. However, the Thermarest Neoair Uberlite matt developed a slow leak and I woke up early feeling the ground beneath me.

Third and final night was again warm but there was also some light rain. No condensation in the bivvi and no water penetration. But it was very light rain, and very brief. I had to reinflate the Uberlite matt three times during the night having failed to find the leak. It was loosing air in about 90 mins. I'm pretty sure two of the internal baffles blew on the first night as well. So I'm sending it back. It was always on the ground sheet and I was careful with it. It is impossible to find a slow leak when you are out in the open with the wind blowing around you.

Jdsk
Posts: 2277
Joined: 5 Mar 2019, 5:42pm

Re: Bivvi bags - advice please

Postby Jdsk » 16 Sep 2020, 7:47pm

How old is that mat?

Jonathan

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 16 Sep 2020, 8:35pm

Jdsk wrote:How old is that mat?

Jonathan


Purchased July this year. It blew the two baffles and started leaking on the sixth time I used it. I've failed to find the leak so far. Will persevere tomorrow.

Jdsk
Posts: 2277
Joined: 5 Mar 2019, 5:42pm

Re: Bivvi bags - advice please

Postby Jdsk » 16 Sep 2020, 8:39pm

That's disappointing. Ask for a replacement?

Jonathan

User avatar
NATURAL ANKLING
Posts: 12094
Joined: 24 Oct 2012, 10:43pm
Location: English Riviera

Re: Bivvi bags - advice please

Postby NATURAL ANKLING » 17 Sep 2020, 1:05am

Hi,
Stop using blowups in the late 70s.
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.

User avatar
Sweep
Posts: 6501
Joined: 20 Oct 2011, 4:57pm
Location: London

Re: Bivvi bags - advice please

Postby Sweep » 18 Sep 2020, 2:07pm

Thanks for the update linus - sounds like you had a miserable night.

Just back from a 2 night bivi trip with the british army bivi - not the smallest thing but I think it worth the space and weight.

One thing I won't be taking next time, except for very special circumstances, is the brit army green cotton sleeping bag liner I bought on a whim in Romford market - heavy and bulky for a liner and its velcroed exit sides actually make it harder to get into and stay inside. A right old tangle, though maybe it suits special forces who want to sleep with their boots on and emerge straight from sleep into a firefight.

Back to the Decathlon silk liner - not only is it very light and compact, but it makes wrapping yourself in 3 layers - liner/bag/bivi far easier.
Thoroughly recommended.
Sweep

User avatar
LinusR
Posts: 431
Joined: 24 May 2017, 7:27pm
Location: London
Contact:

Re: Bivvi bags - advice please

Postby LinusR » 19 Sep 2020, 2:48pm

Sweep wrote:Thanks for the update linus - sounds like you had a miserable night.

Just back from a 2 night bivi trip with the british army bivi - not the smallest thing but I think it worth the space and weight.

One thing I won't be taking next time, except for very special circumstances, is the brit army green cotton sleeping bag liner I bought on a whim in Romford market - heavy and bulky for a liner and its velcroed exit sides actually make it harder to get into and stay inside. A right old tangle, though maybe it suits special forces who want to sleep with their boots on and emerge straight from sleep into a firefight.

Back to the Decathlon silk liner - not only is it very light and compact, but it makes wrapping yourself in 3 layers - liner/bag/bivi far easier.
Thoroughly recommended.


A cotton liner is not a good idea. Sounds like the silk one is good. I used to use cotton but my 20-year-old Pertex liner is much better and makes a noticeable difference to warmth and is easy to clean.

After inflating the Uberlite mat and putting it in the bath I eventually found the hole - which is actually quite noticeable once you have a lot of bath water to play with. Oddly it is on the upper side of the matt right behind where I would place my head and pillow. I've patched it with the repair kit that came with the mat and it's holding air. But I'm still minded to send it back or exchange it for something more durable because of the three internal baffles that broke.