I know my bike isn't really a touring bike, but i figure i can get by with it as long as i keep my load light.
the bag is big enough to carry some quick access gear while touring (wind jacket/pants, warmer gloves, etc), otherwise i can use it to carry wallet, phone, flat repair gear, snacks, etc. for long day rides. im also going to build a tank bag too for long day rides. I think i'll also build a full size frame bag for some actual multi-day touring in the fall.
This one is built with 1000 denier cordura, #5 water resistant zipper on the right side with a flap to help keep it dry/clean, and 2" velcro. the bag is a hair over 3 ounces. It ended up being slightly taller in the rear than it should have been, so it's not as tight as i would have liked it to be, but it still works well. since i don't have a sewing machine, i hand-stitched this.
I still have enough cordura to make more of these, however i think im going to go with some lighter material like X-PAC since it will be easier to stich together and will result in an overall lighter bag. However this cordura seems like its bomber and will last forever.
