bivvy bag

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guitarplayer
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bivvy bag

Post by guitarplayer »

Hi outdoor enthusiasts, a question to you about bivvy bags. I read on my favourite Tom's Bike Trip that he uses Alpkit Hunka which accidentally was featured in a Guardian article today.

New ones are £49.99/70$ and I found used ones on eBay for not less than £40.00/56$ which is a good sign.

However, I also see cheap £10/14$ ones on eBay.

Neither DW nor I have ever done bivvying in the UK, but hopefully planning to later this month if we get bivvy bags. The weather is meant to be >10C/50F night and we will have a tent as a back up for rainy nights.

Will the cheap one do?

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Jean
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Re: bivvy bag

Post by Jean »

It will protect you from dew or some rain, but not from your humidity condensing on the inside of your bivybag, so you won't avoid having to dry the sleeping bag afterward. I see it more as a back up to avoid being completly soaked and frozen if it rains (but you'll still be wet under heavy rain). It works well in combination with a very small tarp (like a poncho) if it's windy. So if you are going to carry a tent anyway, i'de just go without a bivy bag. I did many trip without a tent, at home in switzerland, but also all around the north atlantic and in higher mountain abroad and those are my conclusion.

guitarplayer
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Re: bivvy bag

Post by guitarplayer »

Hmm I see. My idea was to do wild camping and the appeal of a bivvy bag would be that the bivvy bag based sleeping system can be set up and rolled up in maybe 5 min vs 30/40min of unpacking/packing a tent. This would earn about an hour of time for other activities, for example having a 1h break in the middle of the day to rest and possibly dry the damp sleeping bag :)

I can see how condensation might be an issue especially with down sleeping bags. Do you know if the condensation problem is alleviated with better quality/pricier bivvy bags like e.g. Aplkit Hunka vs the cheapest you can get?

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Jean
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Re: bivvy bag

Post by Jean »

I have a 400.- bivy bag and a 25.- bivy bag. It's better with the expensive one, but not perfect either. For winter bivouacing, I use an inner waterproof bag, which solve the condensation probelm entirely. What i meant, is that the bivvy bag is only really usefull if it rains, or if it's very windy. If it isnt, you can just sleep with your sleeping bag on your matress. If it is, you said you were going to carry a tent anyway. They are an ok replacement for a tent if for any reason, you do not wan't to put up a tent. Also, as you said, It's more of a problem with down sleeping bag. I only use down in winter (when it's really cold and a synthetic bag would be to heavy) or in very dry condition. Down works fine in a tent, but with nothing or a bivvy bag, you'll be better of with a synthetic sleeping bag.
Anyway, as the worst case scenario is a bad night, i'de just go with wathever sleeping bag you have, and no bivvy bag, and the tent as backup. You'll probably have to take advantage of some sunshine to dry your sleeping bag but a bivvy bag wouldn't avoid that.

TLDR: Bivy bag will make you less wet, not dry.

guitarplayer
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Re: bivvy bag

Post by guitarplayer »

Ah now I get what you mean, just a mattress and a sleeping bag!

Strangely, I never thought about it because I thought dew would soak the sleeping bag big time and unfortunately I only have the down one. So when you sleep without a tent, do you have anything to put under the mattress?

I might give it a shot tonight, there will be 8C and <10% chance of rain.

I understand then that you recon a tent is always superior to a bivvy bag, it you could choose between the two / bivvy would be the choice when taking a tent is not an option.

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Jean
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Re: bivvy bag

Post by Jean »

The dew in the morning is hard to predict exactly. It depends on how fast the temperature changes during the night and morning. Sometimes there is no dew at all, sometimes i'm wet. If you can dry your sleeping bag during the day (either because it's sunny, or because you have access to a dry and warm place), dew isn't usually enough to be a problem. Otherwise, it's an acumulation problem, your sleeping bag will be less and less warm, until it's too cold to sleep.

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Ego
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Re: bivvy bag

Post by Ego »

guitarplayer wrote:
Wed Jun 16, 2021 8:14 am
Neither DW nor I have ever done bivvying in the UK, but hopefully planning to later this month if we get bivvy bags. The weather is meant to be >10C/50F night and we will have a tent as a back up for rainy nights.
If you are carrying a tent then a bivy is just extra weight with little benefit.

A bivy is great for one person as the weight is less than a one person tent and it is simple. A two person tent is better than two bivys unless you don't want to sleep with the other person. Some bivys have tent-like mosquito netting which is helps with venting.

Tom travels in the Caucasus which has a particular weather.

AxelHeyst
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Re: bivvy bag

Post by AxelHeyst »

If your tent takes 30-40 min to set up, somethings up. Is it 40 years old? Or do you maybe need to practice more? My ten year old two person tent (Rei half dome 2) sets up or packs down in five minutes. I like the idea of a bivvy but modern tents are pretty good, and cover more situations than bivvys.

sky
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Re: bivvy bag

Post by sky »

I use a Borah Bivy https://www.borahgear.com/sidebivy.html with a tarp as a somewhat cheap shelter for trailside camping, that is, not in a campground but sort of stealth camping along side a trail. The main reason I use a bivy is to keep bugs and creepy crawlies off of me. I generally camp in the North Woods with heavy bug pressure and ticks that carry diseases.

I think that a tent with bug netting is the ideal method but the lightweight tents tend to be expensive. There may be some chinese tents out there that I don't know about that are light and less expensive. If I had a lightweight tent of the same weight as my tarp/bivy combo, I would use the tent.

I would recommend getting a bivy with as much bug screen as possible. The reason is, in cold weather, condensation can be a problem with water resistant fabrics, so more ventilation (more bugscreen) is good. In hot weather, more airflow (more bugscreen) for more comfort is good. I would not use a bivy that is supposed to be waterproof, that would be condensation hell. Your tarp is the tool to keep the water off. The bivy keeps the bugs off.

Another thing about bivys is to get one that is longer and wider than you might think you need. That helps with being able to move around inside and not get claustrophobic.

I had issues with getting bit by mosquitos through the bugnet, so I sewed a few krinkled up layers of bugnet to my bugnet. That means the stingers can't reach my skin anymore.

The kind of camping they are writing about in the Guardian article, I would not use a bivy for that. I would use a tarp and lay on half the tarp, and if I needed protection from rain or dew, I would pull the other half of the tarp over me, leaving the sides open. The problem is that this method has a high chance of failure in heavy rain. After you live through a night getting soaked, you will decide to never do that again. But if it is not going to rain, you can sleep well cowboy camping out in the open.

guitarplayer
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Re: bivvy bag

Post by guitarplayer »

Thanks all, this is all really useful.

@Ego, yes it seems to me more and more that a bivvy is not for DW and I, either a tent which we are very happy sharing or sleep under the open sky.

Tom travels very currently in the Caucasus, walking the 500miles+ hiking trial through Armenia that he has designed, but I think in the past he used to travel all over in various climates.

@AlexHeyst, sorry I should clarify. It it not so much the very setting up of the tent (it is about 10 years old as well, Hannah Serak S), which would take less than 30-40min, I might check how long it takes today. What I had in mind was that setting up the tent invites taking the panniers off the bike, unpacking some things, maybe cooking, then leaving the cooking gear out to dry and packing it up the next morning etc. In my last trip it was my experience that, all these things considered, it would take me about 30-40min from the moment I decided to get up to the moment I sit on my bike ready to cycle. My idea with the bivvy was to compress the sleeping to just sleeping, but now based on what people write here I come to a conclusion that bivvy is probably not the way to go. Either a tent (and maybe just behaviourally limit other activities, ha) or nothing at all.

@sky, this is some useful advice! My tent is okay, I don't mind the 2.6kg of it and it does the job really well. On a bike when touring, the weight seems much less of an issue than while hiking or bikepacking, someone even did an experiment to find out. And yes, a tarp! @Jean also mentioned it actually now that I read it again.

I slept outside last night in my Robens 600 Caucasus (3 season down sleeping bag). Very cozy with min temp of 42F and no wind, bugs did not bother me at all. Also beautiful sky. I spread the tent flat underneath, which basically worked a bit as a tarp (I have a themarest pro-lite and it feels like it would soak up water if I had it directly n the ground). In the morning the outside of the sleeping bag was slightly damp. I try to emulate doing it when on a trip, so the sleeping bag is packed now. I will take it out about midday for 30min/1h outside and see if it dries okay.

ETA: it dried okay very quickly in the sun, I am going to try it out on my next trip.

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