I have back packed, horse packed and bike packed in all kinds of weather in all kinds of terrain in ever season of the year. This is the bedroll I've used for years under all conditions sleeping out at -35 degrees. I went down to the local army surplus store and bought a used sleeping bag set used by the Canadian Army. The set consisted of 2 eiderdown mummy bags and a felt type inner cloth liner. I just use one bag with liner in the summer. As far as I'm concerned,, eiderdown is the only way to go. It's light weight, holds the heat and is also cool in the summer. If the bag gets wet it will dry fast. Man has tried to make many different materials to fill sleeping bags but mother nature does it best.
The bags and liner fit and tie into each other to make one very warm bag. You can also get a water proof outer bag that the sleeping bags fits into and acts as a ground sheet. Instead of using their outer bag which was made up off a more rubbery type material. I made one up myself by purchasing a used 8x10 army style tarpaulin ( no holes ). The material weight of this type of tarpaulin is not that heavy or thick. The army type tarpaulin has already been treated with a water proofing oil substance. The tarp although water proof, will also breath so you won't build up condensation once your inside all the bags.
I took the tarp down to an upholstery shop and got them to make the outer bag. I used snap buttons up and around 2/3 of one side of the bag to secure it closed. You could also use a zipper if you prefer. I also got them to sew a little flap pouch inside at the top of the bag to store a small pillow or spare set of cloths. Now the most important item I added inside this bedroll was an air mattress. The secret to keeping warm, dry or cool is to get off the ground. I have tried every new fancy camping mattress on the market but you can't beat the good old blow up air mattress. They're cheap, takes up the least amount of space, gives the greatest height off the ground and if you happen to camp by a lake or stream you got a boat.
When my bedroll is complete, I use a small length of cord to keep it either rolled up or folded up then secure it to the bike with bungee cords. It is water proof and all the contents are protected from the weather. The small length of cord used to tie the bedroll up sure come in handy while camping. I've thrown this bedroll down in the mud, wet grass and used it without a tent in the rain. Climbed in snapped the bag closed and was dry and warm as toast.
From time to time the outer bag needs to be treated with a water proof compound. The folks from Australia who make the Aussie Outback coats and pants make a very good water proof compound. If you can get a hold of some bee's wax and good quality leather oil. Heat up both items mixed them together, apply over the outer bag for the same effect. Total cost of my complete bedroll was 60 dollars and it weighs about 15 lbs. I'll put it up against any sleeping bag any where.
As a final note ... checkout what your military uses in your country and adapt it to your own personal use.
[This message has been edited by Windwalker (edited 13 July 2003).]