Planning My Frame Bag

[cavscout]

I've got some VX21 coming in the group buy so I'm in the process of designing my first frame bag and would like a set of eyes with actual experience to look it over and offer your critique.

Legend: (in case all my symbols are unclear)

Black Hollow rectangles = tri-glides for lashing something onto the side
square red/grey tab near steer tube = water tube hole.  The tab is a storm flap to seal the hole when not in use. (over thinking it a bit? 
Black dotted lines = Zippers
Blue/White grid = Internal Mesh Map Pocket (might like an external also for things I don't want to unzip for)
Blue dashed horizontal line = Velcro divider shelf.  Might add a flap over the hook side to prevent snagging on lycra and knit clothing when not in use.

I'll probably make VX21 tabs to attach the velcro frame straps to rather than sew the velcro directly into the seam.  Any pros and cons?  Thanks,

[trebor]

pretty good layout. common to what most DIY'ers are doing. out of what material are you making the "spine"? (the piece that touches the frame and joins the two sides)

if from VX21, it might wear through in a few hundred miles or so from abrasion against the frame. something to think about.

the water hose port is not a bad idea... a lot of extra thinking and sewing. as you assemble the bag, you'll likely "discover" that with correct placement, the spine material itself can give you what you desire. think about that for a minute and it'll come to you....

[cavscout]

I was planning on using VX21 for the spine, but don't want to build in a weakness.  Is a heavier cordura better suited, or what about a 2" wide polypro webbing?

I figure the storm flap on the hose port is overkill but might do it just to be a little different.

[trebor]

I use cordura (500 or heavier). Webbing works too.

Enjoy the build!