Bivi bag for large sleeping mats?

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hughtrimble

Full Member
Jan 23, 2012
467
81
UK/France
Evening bushcrafters,

I've got an Exped Synmat Winter UL LW and in advance of an upcoming trip just tried to fit it into my British military Goretex bivi bag - it fits, but not with enough space left for me to lie in it in a sleeping bag.

The pad is:
Thickness: 9 cm
Length: 197 cm
Width at top and bottom: 65 cm

Any pointers to a bivi bag that would fit this plus me and a sleeping bag? Would an XL bag fit this, or do they just increase the length rather than overall internal thickness capacity?

Hugh
 

SaraR

Full Member
Mar 25, 2017
1,638
1,187
Ceredigion
I just have the sleeping pad on the outside, underneath the bivvy bag. If I’m worried about an inflatable mat, I usually have a thin foam mat or a ground sheet to protect it.
 

hughtrimble

Full Member
Jan 23, 2012
467
81
UK/France
I just have the sleeping pad on the outside, underneath the bivvy bag. If I’m worried about an inflatable mat, I usually have a thin foam mat or a ground sheet to protect it.
Hi Sara,
Yes unfortunately this is for use without a tarp so it needs to be inside the bivi bag with me.

Wondering if anyone knows if the Alpkit Hunka XL might work? Though no zip...and zips are such a QoL improver on bivis!
 

Barney Rubble

Settler
Sep 16, 2013
553
283
Rochester, Kent
youtube.com
If you're struggling to fit the mat in a British army bivvy then I suspect you're going to be a little stumped as I don't think you'll find a bivvy bag that's bigger.

Even if you plan to sleep out without the tarp then you should be absolutely fine to leave the sleeping pad outside the bivvy. They should be waterproof and I've done that several times with my Exped Downmat. Indeed, most bivvy bags are designed to cover the sleeping bag and nothing else.
 
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Erbswurst

Bushcrafter (boy, I've got a lot to say!)
Mar 5, 2018
4,079
1,767
Berlin
Nowadays there are a lot of equipment systems on the market that do not fit well together. Such a fat mat I even wouldn't put into my tent.

It's always sensible to ask here before you buy equipment, not afterwards. But I put the mats under the bivvy bags anyway.

The French army bivvy bags look more rectangular in the first view, but I doubt that they are really larger than the others, because a bivvy bag works the better the closer it fits around the sleeping bag. That's a very good reason to put the mat under the bivvy bag and not inside.

In my opinion you got there a comfortable mat for car camping with very roomy tents. If you didn't use it yet you probably should try to change it against a trekking mat.
 

hughtrimble

Full Member
Jan 23, 2012
467
81
UK/France
If you're struggling to fit the mat in a British army bivvy then I suspect you're going to be a little stumped as I don't think you'll find a bivvy bag that's bigger.

Even if you plan to sleep out without the tarp then you should be absolutely fine to leave the sleeping pad outside the bivvy. They should be waterproof and I've done that several times with my Exped Downmat. Indeed, most bivvy bags are designed to cover the sleeping bag and nothing else.
I've always been advised to keep mats inside the bivi, even on residential bushcraft courses by the instructors - I must say I prefer to keep them inside for the protection the bivi provides, but with this particular mat it seems it may not be possible!
 
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hughtrimble

Full Member
Jan 23, 2012
467
81
UK/France
Nowadays there are a lot of equipment systems on the market that do not fit well together. Such a fat mat I even wouldn't put into my tent.

It's always sensible to ask here before you buy equipment, not afterwards. But I put the mats under the bivvy bags anyway.

The French army bivvy bags look more rectangular in the first view, but I doubt that they are really larger than the others, because a bivvy bag works the better the closer it fits around the sleeping bag. That's a very good reason to put the mat under the bivvy bag and not inside.

In my opinion you got there a comfortable mat for car camping with very roomy tents. If you didn't use it yet you probably should try to change it against a trekking mat.
The mat is designed for use with the Amok system, so it's sticking around! To be honest, a bivi is quite far down my list of shelters, but I do really enjoy the exposure and thus views afforded by such minimal protection.

I'm not sure why you think it's a car camping or big tent mat? I use it in my Amok and Terra Nova Super Quasar. Those who need a high R value and also prioritise sleep quality over pack size go for such mats as they are superior to thinner, narrower mats in those regards.

That aside, I'll check out the French army bivi, thank you for the suggestion.
 
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Barney Rubble

Settler
Sep 16, 2013
553
283
Rochester, Kent
youtube.com
I've always been advised to keep mats inside the bivi, even on residential bushcraft courses by the instructors - I must say I prefer to keep them inside for the protection the bivi provides, but with this particular mat it seems it may not be possible!

Agreed, it is always better to have the pad inside the bivvy if possible as it adds a layer of protection and also stops you rolling off the side of the mat. Unfortunately this preference becomes a little tricky with the more modern inflatable pads that are getting thicker and thicker.

If I were you, I'd stick with your existing bivvy (because the Brit army bivvy is awesome in every other way), put the pad underneath and treat yourself to a German Army Ribbed Groundsheet (often known as the Elephant skin!) which can add a layer of protection to your pad. These groundsheets are a great size for bivvy camping (approx 2.4x1m), very good quality and can usually be bought for five or six quid.
 

Madriverrob

Native
Feb 4, 2008
1,500
319
57
Whitby , North Yorkshire
Have a look at the sierra designs back country 3000 bivvy or the Robens Mountain Bivvy , both have side zips and a pretty roomy although I cant guarantee they will suit your requirements .
 
Apr 8, 2009
1,165
144
Ashdown Forest
from my perspective, I agree with a few of the posts above - rather than spend a few hundred quid in a search to find a bivi bag that goes over your mat to protect it from the ground, why not spend a few quid for a rectangular sheet of nylon/cut down ground sheet/kip sheet to go between the mat and the ground? Lets not forget that you also dont really want your bivy bag touching the ground either in an ideal world - getting muddy and with its membrane at risk from sharp pointy things. Personally - although clearly it's a thing from the messages above - I've never known anybody to put their sleeping mat inside a bivy bag - with the exception of hooped bags which are more tent like, and frequently have non-breathable floors.
 
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BumblingAlong

Tenderfoot
Jun 20, 2021
93
39
51
Winchester
Other than the army bivvy the closest to your criteria might be the zipped Robens Mountain Bivvy. It's new to the market so there aren't any reviews apart from an unboxing on YouTube which is well worth a watch. It's certainly spacious, has mosquito net and an intriguingly obvious way of raising the head area using cordage making it akin to a hooped bivvy with the hoop. It's as breathable and durable as the makers claim it could be a game changer. One to watch
 

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