do I need a bivy with a tarp?

[Askel]

Hi

I'm new to this forum and new to bushcraft. I've been a scout when I was a kid, and I love hiking. But now during the simmer I stumbled upon a few blogs and forums about bushcraft and got very interesded.

The thing is that I'm going to buy a new sleepingbag for 3-season use (and in southern Sweden, 4-season).
I've been looking a lot at the surplus US modular sleep system that I can get with freight, taxes and a better stuffsac for about 110 €. (Patrolbag for something like 0C (~1kg), thick bag for something like -10c (~2kg) and a bivy (~1kg).
The other item I've been looking at is the Marmot Trestles 15 (1,75kg)http://marmot.com/products/details/trestles-15 that cost about 120€.

From reading forums and blogs I get the impression that the Trestles and the black thick MSS bag are similar when it comes to temperatureratings. (The MSS doesn't have any official ratings though so it's only based on users impressions, which varies.) The MSS-bag is a few hundred grams hevier though.

I plan to use my sleepingbag both when hiking in the lowlands and in the Nordic mountains with a tent. But I also want to be able to use it for more bushcraft-style campsite. I plan to use a regular hardwarestore tarp and the sleepingbag when I'm out by myself.
Now to the question. Do I need a bivy when I have a tarp. Which of the alternatives do you recomend? I want a good bag thats durable but still not to heavy. I want it to suit both multiday hikes and bushcraftstyle campsite with homemade shelters. Is it even possible to combine?

//Askel

 

[Angry Pirate]

Personally I would go for the Marmot bag. I have never been a fan of military bags, having used a few in my time (admittedly British issue ones): they are far heavier than the civilian alternatives, they use technology that is years out of date, i.e. the filling is older hence is much heavier and less thermally efficient. They are heavier duty for sleeping with your boots on inside the bag and often have central zips (great if you expect to get bumped in the night but far less useful for camping use). The American system at over 4 kg is ridiculously heavy and bulky. You could halve that weight and be comfortable.
I use down bags for backpacking and mountaineering, I have a Mountain Equipment Snowline for winter use (1.3 kg) and a Mountain Equipment Helium bag for summer (700g). They cost a lot but the snowline is 20 years old now so a worthwhile investment. For bushcraft use I tend to use my old 2 season synthetic bag (a Daimor Morlich - sadly not made anymore) which is 1.1kg and again has lasted a lot of years. I prefer synthetic for biviing as it is less of an issue getting it wet and it can machine wash easily. If I need a warmer bag I can put the Helium inside the Morlich to get a 4 season bag with synthetic outer (issues with dewpoint when biviing in winter) for under 2kg.
I always use a bivi bag when under a tarp. Less for waterproofing than to keep the bag clean in case I come off my thermarest. It also gives me options for if I can't rig a tarp properly. I use a British issue one as they are cheap and work well.
Hope this helps!

 

[Didgeridoohan]

Apart from reasons stated above, I usually use a thin bivvy with a mosquito net when under a tarp. Hate the little buggers...

 

[bearbait]

Having a bivvy bag ouside your sleeping bag can add quite a bit of warmth, particularly if there is any breeze blowing, due to the slightly warm and still air maintained outside your sleeping bag, perhaps adding 1/2 to 1 season's worth to your sleeping bag.

 

[Askel]

Thanks for your inputs.
I've more or less decided to go with the Marmot-bag. My thoughts of using a bivy was mostly, like Angry Pirate, to protect it from getting dirty. I'll buy some tyvek to use as a groundsheet for now to protect it. I don't have the money to spend on a bivy right now, but I have been looking at the Alpkit Hunka. But that will be something I'll buy later on.

//Askel

 

[Askel]

Didgeridoohan:
Do you know any good place in Sweden to get Tyvek?

 

[Squidders]

I can't stand being in a bivy bag so I have never done it... last Christmas my partner got me one of these and I couldn't be happier, just throw in a thermarest and sleeping bag and you're set for a good nights sleep. the bath tub floor mean that if there is very heavy rain and some runs through, i'm still protected.

http://www.ultralightoutdoorgear.co...-accessories-c315/element-solo-bug-tent-p1756

 

[shaggystu]

I can't stand being in a bivy bag so I have never done it... last Christmas my partner got me one of these and I couldn't be happier, just throw in a thermarest and sleeping bag and you're set for a good nights sleep. the bath tub floor mean that if there is very heavy rain and some runs through, i'm still protected.

http://www.ultralightoutdoorgear.co...-accessories-c315/element-solo-bug-tent-p1756

I use a bivvy bag (either a british army one or the Alpkit hunka) and find them to be really useful and practical pieces of kit that do the job they were designed for generally very well. However, I've been thinking about getting the RAB bug net in Squidders' link for a while now, and will do as soon as it gets to the top of my list. It looks like a great piece of kit.

Cheers,

Stuart.

 

[Trig]

I just ordered one of these yesterday http://www.titaniumgoat.com/Kestrel-Bivy.html
Couldnt find anything similar in the uk, but wasnt too bad at £60 odd pound from us inc shipping.

Top material isnt fully waterproof, so for under cover only, but its lightweight and will keep the breeze and midges off you. Can be hung up to keep it off your face slightly also.

 

[ozzy1977]

I use the US MSS bivvy bag and either a basha, DD 3x3 or 4x4, only bug net I have is on my hammock

 

[Didgeridoohan]

Didgeridoohan:
Do you know any good place in Sweden to get Tyvek?

Unfortunately no... But I'd do a search at http://www.utsidan.se. Bound to be someone there who knows.

 

[verney]

Didgeridoohan:
Do you know any good place in Sweden to get Tyvek?

Ask your local hardware store or painting supplies seller.

 

[santaman2000]

.....The thing is that I'm going to buy a new sleepingbag for 3-season use (and in southern Sweden, 4-season).
I've been looking a lot at the surplus US modular sleep system that I can get with freight, taxes and a better stuffsac for about 110 €. (Patrolbag for something like 0C (~1kg), thick bag for something like -10c (~2kg) and a bivy (~1kg)......

....(The MSS doesn't have any official ratings though so it's only based on users impressions, which varies.).....

The "official" ratings for the US system or as follows:
Bivy alone = 60f (15.5c) and is about 1.5 pounds (.68 kilos)
Patrol (green) bag alone = 30f to 50f (-1.1c to 10c) and is about 3 pounds (1.36 kilos)
Intermediate (black) bag alone = -10f to 30f (-23c to1.1c) and is about 4 pounds (1.82 kilos
Full sleep system (black bag, inside green bag, inside bivy) = -30f (-34.4c)

Bear in mind these ratings are NOT! meant to be taken that you will get a "comfortable" nights sleep in these temps. They mean that if you sleep as the military are taught (wearing the military grade sleep wear, which is essentially military grade thermal underwear) you will get 4 to 6 hours of sleep.

The complete system weighs about 8.5 pounds (3.86 kilos) including the stuff sack, and extremely bulky. BUT!! You don't carry the entire system unless you expect to camp in the lowest end of the temperature range; otherwise, you only carry what you will need for the individual trip. The green patrol bag is my go to Summer bag; it's not only light (much lighter than the published figure official above) but it will stuff down to a little bit larger than a coffee can.

Also bear in mind that the weights are for the "regular" size and that the "tall/long" size will obviously be slightly heavier.

 

[santaman2000]

.....They are heavier duty for sleeping with your boots on inside the bag and often have central zips (great if you expect to get bumped in the night but far less useful for camping use).....

The US MMSS has side zips. And no bag I've ever used (military or civilian) was made to take your boots into the bag. Certainly not this one.

 

[Quixoticgeek]

Hi
Now to the question. Do I need a bivy when I have a tarp. Which of the alternatives do you recomend? I want a good bag thats durable but still not to heavy. I want it to suit both multiday hikes and bushcraftstyle campsite with homemade shelters. Is it even possible to combine?

Short answer: No.

Longer answer: Depends:

Detailed answer: I tend to use a bivvi bag when sleeping under a tarp. I do this for a couple of reasons. 1: If I roll of my matt out the side of the tarp, I'm not going to get wet... If the wind direction changes while I am asleep and the rain starts to come in, I'm not going to get wet either. 2: Wet can come without rain in the form of dew, the bivvi bag helps reduce the effect this has, which keeps me drier. I therefore always use a bivvi bag under the tarp.

That said, I don't always use a tarp over the bivvi. If the weather is clear and there is no forecast of rain, I'll just use the bivvi bag and enjoy the view of the stars.

Do note: breathable fabrics like goretex work best if there is some air flow over the membrane. On a completely still night, you will get condensation on the inside of the bag, nothing will stop that. With this in mind, I try to camp so that I am out the main wind, but with some air flow, just enough that you can perceive it, but not enough it's making you cold.

For a lot more info on bivvi bags than you could possibly hope to have, The Book of the Bivvi is worth a read.

They are heavier duty for sleeping with your boots on inside the bag and often have central zips (great if you expect to get bumped in the night but far less useful for camping use).

I would say the complete opposite. A central zip on a sleeping bag is IMHO the better design. I don't understand why you wouldn't want a centre zip. Both my sleeping bags have centre zips, as will my future bags. A lot of military bags, tend to have a slightly reinforced foot box so that you can wear your boots in the bag. Personally I think that's not the brightest idea. If the weather is forecast to be cold, I tend to put my shoes in a bag, and put them in the bottom of my sleeping bag so they don't freeze during the night.

Julia

 

[santaman2000]

.......... A lot of military bags, tend to have a slightly reinforced foot box so that you can wear your boots in the bag. Personally I think that's not the brightest idea. If the weather is forecast to be cold, I tend to put my shoes in a bag, and put them in the bottom of my sleeping bag so they don't freeze during the night.

Julia

True, a lot of military bags have better reinforced foot boxes (although the US MMSS isn't one of them) but I've yet to see one big enough to wear boots in. And as you said, "....it's not the brightest idea."

While I've never tried a bag with a center zip, I have to concede that it certainly seems that it should be better than a side zip; unless it's a rectangular bag and you want the option of joining two bags together into a double bag as I used to do when camplng with my fiancé.

 

[Angry Pirate]

True, a lot of military bags have better reinforced foot boxes (although the US MMSS isn't one of them) but I've yet to see one big enough to wear boots in. And as you said, "....it's not the brightest idea."

While I've never tried a bag with a center zip, I have to concede that it certainly seems that it should be better than a side zip; unless it's a rectangular bag and you want the option of joining two bags together into a double bag as I used to do when camplng with my fiancé.

I've used the British sleeping system bag quite extensively and we routinely slept in them with our boots on (and our rifles)
I wouldn't say I was huge but I'm 6' with size 10 boots and there was plenty of space. I wouldn't camp usually with footwear on but that wasn't a luxury we had as we could have been bumped at a moment's notice and had to be good to go. The irony that the issued bivi bag had no zip, thus negating the centre zip was not lost on me!

Side zips came about primarily to maximise the warmth to weight ratio of a sleeping bag by shifting the cold spot of the zip away from the chest area, i.e.the core to the side out of the way. The bonus is then they could do left hand zips (for right handed folk) and right zips (for left handers) with the ability to zip them together. I have joined two mummy bags and slept in them with my other half. I don't think it's a coincidence that almost all sleeping bag manufacturers only produce side-zipped bags. (The only exception off the top of my head is snugpak but that's in their forces range)

 

[Askel]

I ended up buying the Marmot-bag now that my paycheck (with lots of overtime) came in. I'll get myself a bivy later on, but to avoid discussions with my wife about what to prioritize I'll probably wait and buy it another month. But if anyone here has a spare bivy they want to sell you're welcome to send me a message.

//Axel

 

[rg598]

For a sleeping bag in that price range I would go with a Mountain Hardwear Ultra Lamina 0. It's one of the best bags out there for three season use. Look around online and you will find it at a good price. I don't use a bivi when using a tarp. The US MSS bivi is very heavy (about 2 lb).

 

[Askel]

For a sleeping bag in that price range I would go with a Mountain Hardwear Ultra Lamina 0. It's one of the best bags out there for three season use. Look around online and you will find it at a good price. I don't use a bivi when using a tarp. The US MSS bivi is very heavy (about 2 lb).

Hi

I read about the Ultra Lamina, and it seems great. But hard to get a hold of in Sweden and would probably be to expensive. Lamina 0 (not Ultralamina) cost 1759 SEK compared to the Marmot-bag for 1195 SEK. I hope that the Marmot-bag will be a good choice now that I've ordered it.
Btw I read your review on the MSS in your blog earlier this summer. It was a really good review.

//Axel