Bivvy bag VS waterproof sleeping bag

[dameunmate]

Trying to cut down on weight, I currently find random shelters and use a down sleeping bag on a Thermarest mat all inside the Alpkit Hunka XL bivvy bag. This works well.

Could I save the 550g of bivvy bag and make do with just a fully waterproofed sleeping bag?

Has anyone tried just waterproof sleeping bag on sleeping mat and nothing else?

I'm looking at some from http://www.phdesigns.co.uk which have the option for HS2 waterproof breathable outer lining with fully taped seams.

[bigjim]

Do you mean shelters as in empty buildings etc? If so why do you need the bag to be waterproof?

[dameunmate]

No unfortunately I don't find many empty buildings where I'm touring, so I need either a waterproof sleeping bag or a waterproof sleeping bag cover/bivvy bag like I use now. I'm assuming a waterproof sleeping bag is lighter and less hassle than having to carry and set up both a standard sleeping bag and a bivvy bag.

All that needs to change is the outer lining of the sleeping bag to a waterproof taped shell.

I try to find some shelter like a bridge or a porch but I can't always guarantee that a puddle won't form from rain nearby, hence the precaution. Also useful for camping with a small tarp, where the foot of the bag may be out in the rain.

[boblo]

Problem with a waterproof sleeping bag is there's always one big hole in it.... so you can get in. Even if you pull the hood really tight, there's still a breathing hole. You can gurantee rain will find it's way in there and soak you and your bag.

The other problem is how do you cook/decamp when just using a waterproof sleeping bag in the rain as, again, it's even worse than a bivvy in this respect. That's why people seem to be going for tarps to augment their bivvy set up. IME, proper waterproof outers (e.g. GTX) are often used on down bags when used during winter mountaineering trips to keep tent drips/condensation off the down. Even so, after a few days in a damp environment, the down still gets a bit soggy.

If the forecast is dry and you're out in late spring/summer/early autumn, you could take a chance but I'd be more inclined to take a bivvy. If there was the slightest chance of rain, I'd take a tent (less than 1kg if you get the right one). If bivvying, I'd also be inclined to take a synthetic filled bag tather than down which all but does away with the weight/bulk advantage of bivvying.

[dameunmate]

I'm sorry I should have elaborated on my style of touring - I live outdoors, so most of the time I'm cycling between towns and cities to my next work appointments. A tent is not practical in a city so I bivvy under any shelter I can find.

I have the Alpkit Hunka bivvy bag and pull the drawstring closed so that only my face is exposed, or only mouth and nose in cold conditions but I always breathe outside the bag to avoid condensation problems.

I agree a tarp is the way to go out in the open, but in the city I find some shelter like a porch or bridge if I see rain in the forecast, or if I think there will be lots of dew. At least something to prevent my face getting wet and trust the waterproof bag to take care of the rest of me. Sometimes my jacket thrown over my face is enough in a light shower if out in the open. I can cook/change etc under a shelter.

Hence my question as to whether a waterproof sleeping bag could lighten and simplify my down bag + bivvy bag set up. Are there other practical considerations?

[PW]

Dunno if they're still on the market but my 1980s Buffalo is STILL waterproof to 1/2" rain per hour, warm when it does get wet and self drying if you stay in it. One layer (there used to be 3 available) is toasty with a hoar frost on the outside, I've used it when the toothpaste froze solid in a 1 man tent at Edale before Easter. I also have a Vaude bivvy which I used in all sorts of foul weather in Scotland a couple of summers back. A bit prone to condensation but it allows a bit of room to keep stuff out of the rain and the rain off the sleepers' face. Weight 1kg. Cosy listening to R4 Longwave at midnight with a small Malt. Avon Skin So Soft sprayed round the zips is useful to keep the midgies off.

[pjclinch]

I would suggest a separate cover is preferable for issues of cleanliness. Especially with a down bag keeping it clean will help maintain its performance, and having a separate cover will make that easier. Also the case that when conditions are ideal you can sleep on the cover, which will up the breathability of the whole system and you'll end up with less moisture in the baffles.

My guess is that with very frequent use as you outline these issues may well outweigh saving the weight of the bivvi bag in the longer term. An occasional planned lightweight overnighter might be a different matter.

Pete.

[dameunmate]

Since I posted my question, I've spent two days washing and drying my down sleeping bag (not a waterproof one), and now I couldn't agree more!

I think I'll carry an extra 100g of silk liner and 550g of bivvy bag, and keep my down clean. As usual the modular approach wins, you are right it seems much more practical. Probably warmer too.

To compensate a bit at least I save 200g with an ultralight shell for the down sleeping bag as opposed to a waterproof one.

[phil parker]

I think it is a wise idea! The additional weight of the external bivi may provide a more robust and protective cover for your down sleeping bag than the lightweight and waterproof exterior of a PHD custom design. I always use a silk liner with my down bags to increase the longevity of the bag as well as being more convenient in hygiene!

[bigjim]

I'm sorry I should have elaborated on my style of touring - I live outdoors, so most of the time I'm cycling between towns and cities to my next work appointments. A tent is not practical in a city so I bivvy under any shelter I can find

So you are not touring [as in a holiday]then but moving between jobs. Are you homeless or saving on hotels etc?

[boblo]

Is he the 'mobile' piano tuner...?

[dameunmate]

Yes I am indeed. I tired of paying rent and getting nowhere in life, so now I'm experimenting with a life outdoors. That means some nights outdoors and some nights at friends'/relatives'.

I started in March this year, so far it has been the happiest time of my life!

Why not turn a fun hobby into a way of life? The money I used to throw away on rent, can now buy me the best in outdoors gear which is mine to keep

[boblo]

Not wishing to be personal, but how di you manage to arrive at Clients without the 'odour of the street' becoming an issue? Presumably there are sufficinet public amenities to ensure this doesn't become a problem?

[dameunmate]

A bit muddy sometimes, but that's because I have a fetish for the off-road routes on muddy bridleways.

However there is no 'odour of the street', there's an abundance of places to wash. England is full of beautiful rivers, canals, and lakes, some of the cleanest in Europe.

For the Winter there are sports centres, friend's houses, and even homeless day centres. I've even filled up my Ortlieb waterbag from somebody's hot tap, hung it on a tree and had a warm shower in the woods.

There's no excuse for being smelly if you're homeless, that's just laziness in my opinion.

See my new web-site for more: http://www.TouringPianoTuner.com click 'blog'.

[ma0mpt]

I am sailor more than a cyclist and have a waterproof marine sleeping bag. It is not down-filled but has layers of fleecy type material which can be unzipped for washing. Not cheap, but very well made and fully waterproof and breathable.

http://www.oceansleepwear.com