Bivi bag only?

[Bearbonesnorm]

Saw this thread and hoped it would answer the bivvy issue. It seems though I have the same thoughts as a few others. Having said that I have decided to take the plunge and get a bivvy for some overnighters I have planned. if I team it up with a tarp just in case it rains I can still get the both down to combined weight of 1kg or a bit less. Just about half the weight of the tent. Adding the tarp is the only way I can see of managing poor weather. Next question is use a down bag or synthetic.

That ^ almost reads like using a tarp + bivvy is in someway a failure. The only failures in this case are been cold and wet A bivvy and tarp combined are great, they give you lots of options and allow you to make decisions depending on conditions. Don't view the tarp as something just for rain, used well, it can make a considerable difference to how warm you'll be and how much condensation you'll suffer even when it isn't raining.

On the question of down or synthetic, for me it's down all year round ... I can never understand how people think a sleeping bag is going to become wet enough to (a) hurt it and (b) effect its performance. You'd have to be either very unlucky or extremely careless

Just wondering really about the condensation issue. Wanting to keep the gear weight down and my lightest bag is a marmot atom (needs to be above freezing though!!) but don't want to wreck it in the bivvy bag. Thinking one night should be ok. Reading other posts it seems it shouldnt be too bad so long as I keep my head out.

What bivvy bag have you bought? Some handle condensation better than others, although most will suffer to a degree if the conditions are right - around your feet is generally the worst place.

[Tom]

I used a just Rab Event bivi bag on the TCR. The reason for this was I wanted a waterproof shelter that could be sealed up from mosquitoes and was quick to set up as well as not being fussy where to set up. It poured with rain about six hours after the midnight start and I set the bivi up in a forest whilst the trees were swaying overhead. Probably not the best place to sleep in hindsight. If a branch had fallen it would have knocked me out or impaled me. I didn't bother using my down sleeping bag. I was wearing a waterproof jacket so anything beneath that was damp, warm but not soaking. I took my sodden shoes, socks and jacket off and crawled into my bag as quickly as possible so I didn't lose any heat. I slept for about 3 hours I think and it was still raining when I got up, dressed and set off again. It wasn't comfortable but I did feel refreshed after that. So it can be done even by soft skinned southerners like me. Would I recommend it....nah not unless you're in a race or war or something where you're desperate for cover from the elements. It's so quick to just lay it out when you're tired though but like Lars said you need something to cook under sometimes and incessant rain day and night for a week and I would question whether it really was the best option perhaps. The weather warmed up later in the day so that wasn't an issue plus I could just roll on to the next shop but sometimes that's not an option.
Later next month I'm going on a tour where there's likely to be mixed conditions so for that I'm taking a more lightweight bivy and a tarp tent which should cover all bases whilst still weighing less than a kilo and offering more comfort. If I only had one option where space, weight, adaptability to all conditions and set up time were crucial factors to consider the Event bivy would be it. It's also really uncomfortable when it's hot and there are mozzies about. I sweated loads plus I could hear the mozzies and even though they weren't in my bivy I still thought they were. I good tip I read recently is to wear a peaked cap in the bivy to lift the net away from the head. At least that nasty high pitched noise would be a little from the ears. Ear plugs weren't an option as I needed to be aware of what was around me due to the dodgy paces I was sleeping!

[dingle]

That ^ almost reads like using a tarp + bivvy is in someway a failure."

I didn't mean it to read like that!! I was just wondering if I somehow had missed something obvious when using a bivvy on its own which wouldn't be the first time . I think that I would always take both (if not taking the tent) as its certainly a great cost effective way of getting a lightweight flexible set up.

Not bad idea just to climb in it mind just to get your head down so long as its not to cold.

The down / synthetic bag bit was just to gauge opinion as you hear people talk of saturated down clumping, I agree though if you toss it in a lake or something your probably going to have problems. In normal use it should be fine but its good to hear others experience especially when it backs up your own thoughts. I have just arranged to get a hunka off one of the forum members so shall see how it performs . As this will be my first bivvy bag I am not really sure of what to expect in terms of breathability but they certainly seem popular. I think he next bit of homework will be tarp set ups using the bike.

[ctznsmith]

Would a hunka simply be the best option or is there anything with a bit of bug protection?

I find for bug protection in a drawstring bag, the best option is to wear a head net inside the bag with you.

I tried that and it didn't work very well. It amazing how the buggers get into the bivy before you've drawn the cord!

I'm* going to mod my Hunka to include a bug net.
(*I say I'm, actually my g/f)

Never had a major problem with condensation in a Hunka. My mate (and my g/f actually) has one of those cheap Mountain Warehouse bivy's...erm they get a bit damp!

[Bearbonesnorm]

Maybe this will be of some use. Oh and yes, Hunka's surprisingly breathable helped by having a breathable bottom

http://bearbonesbikepacking.blogspot.co ... -bags.html

[ctznsmith]

Hunka's surprisingly breathable helped by having a breathable bottom

Are you suggesting that it's not very waterproof from ground moisture or that it won't aid your mat in stopping cold ground cooling you?

[Bearbonesnorm]

Are you suggesting that it's not very waterproof from ground moisture or that it won't aid your mat in stopping cold ground cooling you?

Neither, I'm suggesting that the Hunka breaths well because it has double the breathable area of a bag with a heavy duty PU coated, silnylon or cuben base.

[ctznsmith]

Are you suggesting that it's not very waterproof from ground moisture or that it won't aid your mat in stopping cold ground cooling you?

Neither, I'm suggesting that the Hunka breaths well because it has double the breathable area of a bag with a heavy duty PU coated, silnylon or cuben base.

Oh...you're winking emoticon hath confused me.

[Javi]

The Borah Snowside Bivy is very light and fully waterproof. 365 gr
http://borahgear.com/eventbivy.html

Another lighter fully waterproof is the Event sould bivy or the new FKT Cuben Event soul bivy, 265 gr
http://www.mountainlaureldesigns.com/sh ... cts_id=228

No idea of performance other than some on line reviews. Both look very good

[whitestone]

I'm just wondering about the Hunka XL as well since my current bivvy bag isn't quite big enough to take an Exped Synmat Winterlite with Cumulus 150 quilt and PHD Minimus 200 sleeping bag. Well it is big enough for those just that it's not big enough for me as well

My current bag (unknown make) is 84cm wide at the shoulder and 65cm at the foot box.

[Bearbonesnorm]

I'm just wondering about the Hunka XL as well since my current bivvy bag isn't quite big enough to take an Exped Synmat Winterlite with Cumulus 150 quilt and PHD Minimus 200 sleeping bag. Well it is big enough for those just that it's not big enough for me as well

Hunka XL will swallow that lot easily.

[whitestone]

Cheers Stu. Most bivvy bags seem to be in the 84/85cm width at shoulder level, probably assume that the sleeping mat is going to be between it and the ground rather than inside or that the mat is a Karrimat or similar.

Another order to Alpkit methinks

[Cheeky Monkey]

IMO you can go bivi-only but the weight and bulk of some form of tarp is sufficiently low, especially when compared to the many benefits it can give you (others have listed them already), that I'll almost always take both. However the bivi's in this instance are the silnylon type things like a Borah or TiGoat (i.e. not the heavier stuff made of eVent, Goretex etc).

Down all the way. I'm in Stu's camp on this.

[whitestone]

Down bags for me too. You do need to take care but you don't need to be paranoid, the better quality bags have damp resistant coverings so will cope with a night or two of condensation. I carry my sleeping bag inside my bivvy bag as it provides a secondary layer of protection when inside the dry bag on the bike, maybe slightly paranoid but for me the slight increase in bulk due to trapped air when packing is worth it.

I think I've commented before about the Eastern European climbers when out in the Himalaya, if it was clear weather they would stop in the middle of the day get their down bags out and dry/air them out as they'd get damp during the bivvies from snow being blown or dragged in to the bivvy bag overnight. An hour or so's prevention meant that their bags would work as intended and not be a source of concern.

No one right way to do things but in my experience using bivvy bags on their own is better in dry conditions, which of course aren't the conditions they are marketed or bought for.

[Bearbonesnorm]

No one right way to do things but in my experience using bivvy bags on their own is better in dry conditions, which of course aren't the conditions they are marketed or bought for.

A tiny extract from the forthcoming 'book'

There's a few reasons why rain can potentially make the issue of condensation worse. Number one is that you're likely to be wet, number two, humidity will generally be greater and lastly, the breathability of your bivvy bag will decrease if the outer material is saturated. I suppose it's slightly ironic that while the majority of bivvy bags are waterproof, as a standalone shelter, rain makes them practically useless - you'll need to keep riding until the rain stops before resting for the night and stay in bed until it stops in the morning. In reality, if you want to use a bivvy bag as your sole shelter (successfully) conditions will need to be in your favour.

[Cheeky Monkey]

I really hope that somewhere in that book you re-use the phrase "breathable bottom"

[HaYWiRe]

So when you are in these ideal circumstances, doesn't it make the bivi redundant as well? If its really a dry night then isn't simple a thin groundsheet, mat and quilt just the way to go? Maybe a bugnet to cover the lot

Ofcourse dew point would be a factor, so a light water resistant layer may be needed, would dew on a bag be enough to affect its breathability?

Another point would be if it was to only be used in natual shelters or caves/overhanging rock, where a shelter cant be pegs out. So freestanding or not at all. These may be very specific circumstances but very common in my area. Maybe simply moving to somewhere you can peg a tarp really is better.


Or maybe I already know my answer.....a hammock

[whitestone]

I use a bivvy bag as the final wind break in the overall system. First level of defence is existing shelter such as trees, walls, etc. The second level is the tarp but this will usually be pegged out such that there's a gap between the bottom edge of the tarp and the ground giving more room. So having the bivvy bag deals with anything that does get through. Also, no matter how hard you try and careful you are you are likely to touch the inside of the tarp so it prevents condensation from the tarp getting on the bag.