I'm thinking about making a frame bag for my 25" 1985 Raleigh Portage 650B touring bike. It still has the original racks front and rear with a 24L Carradice Camper longflap saddlebag resting on the rear rack. My hiking baseweight is currently around 10 pounds; from spring to fall I can basically get everything in the carradice bag except water, shelter and pad. With a big frame bag, I think I could ditch the front rack and two water bottle holders.

I'm looking for suggestions on how to construct the bag, and what type of material to use.

If I use the whole internal space it would be huge. Will a frame bag that big work? I would think a bag that big would need some partitions and perhaps some support. I was thinking of using my roadmaster pump or shelter pole as a horizonal support in the middle. The pump would work better I think because of the notches it has to fit against frame tubes. My shelter pole is about 1 cm shorter than the pump.

Here are a few photos:

Side shot
http://i154.photobucket.com/albums/s271/RichInBunlyGoodness/25%20inch%20portage/sideshot1.jpg

Image of pump where it would naturally rest:
http://i154.photobucket.com/albums/s271/RichInBunlyGoodness/25%20inch%20portage/portagewithpump.jpg

Image showing 2L Platy, Tarptent Contrail and NeoAir relative to frame:
http://i154.photobucket.com/albums/s271/RichInBunlyGoodness/25%20inch%20portage/portagewithgear.jpg

Frame bags can be very useful for things that are long and narrow, heavy like a water bladder, or you just want to get at a little easier while you ride. Here is a picture of my set up:
http://oceanaircycles.com/2010/12/13/frame-bag-no-01-details/
there is a ton of good information on the bags and how to make them over at:
http://www.bikepacking.net/forum/index.php?www
Just do a search for the words Frame Bag and you will find most of what you ever wanted to know.

Once I had made a couple frame bags I set into making a saddle bag with what I felt were design improvements over what the Carradice I had been using offered. Next up is a handlebar bag that better meets my needs. Then after that is a full set in XPAC that I have on the way.

Rob