I have a dirt cheap synthetic 2 season bag, rated 5 degrees. I use it with my clothes on and with a down jacket too and have never really been cold in it.

Out of interest, is there a rule of thumb for the comfort rating effect of:

Silk liner
Cotton Liner
Bivvy Bag outer
Down jacket
etc etc

or anyone know of any sites with such geekiness? (Outdoors magic not helping)

What a jolly interesting thread.

If you want to win grammar points you should hold off the pedantry until after the edit function is disabled 🙂

Where?

EDIT – ah, I see, a stealth edit has taken place

silk liner adds about 1/2 a season in my experience

Cotton liner is good as you can clean it but not for much else. Rubbish if it's hot and you sweat or if it gets damp.

Fleece liners can work well.

There is no standard for comfort rating so you need to take it with a pinch of salt. I would be reluctant to rely on a bag that would only be adequate if you wore your down jacket. The only reason I can see to do this is if weight is a very serious issue (mountaneering, rock climbing etc.)

Try alpkit, fieldandtrek (used to have stuff), tgo for advice, not sure if it's any good. A few minutes with google will see you right, a lot of manufacturers put this gumph on their websites.

What are you talking about Stoner? Grammar points? I was merely pointing out that this was a jolly interesting thread.

😉

I threw my last sleeping bag out – that way I'd never be tempted to sleep on floors and go camping ever again.

touché

I usually camp light so rely on layering and a down jacket for extra comfort. Ive just been very surprised at how a 2 season cheap bag has been able to keep me snug and packs to only 15cm x 20cm.

I think Trail did a comparison test on temperature ratings 3 or 4 years ago. They used a facility at Leeds University to carry out the tests and a search of their archives amy turn up some useful information. Pertex liner adds about 0.5 season for me but I sleep warm after a day outside.

as above about 1/2 season per layer.

I have a good 3 season bag which stays open when its hot and gets zipped up with a bivi bag on the outside and a down jacket inside when it gets a bit nippy.

The 4 season bag I have weighs a bit too much to carry over the hills.