I just installed a pair of new saddlebags on my '04 Bullet and thought someone might be interested in the mounting setup. As some of you already know, I just purchased the bike a few weeks ago. The bags greatly increase the utility of the bike, and I can now justify its purchase by occasional trips to the local market to purchase and carry home a few essentials, rather than using a less energy efficient car. I know, this is a feeble justification.
The bags are the cheap ones available online for about $60 with free shipping. I made a couple of brackets out of 1/8" x 1" steel bar stock and attached them to the curved frame tube running along the outside of the rear fender. They are attached using two rubber coated clamps. The forward end of the bracket stands out from the frame a couple of inches to allow the bags to clear the rear shock.
There is a second steel bar which bolts through the bag. This bar stands off the bag by 1/8" so it can slip over the bracket. One of the bolts passes through both the bar on the bag and the bracket so the bags will not come off when riding. The bag can be easily removed from the bike by removing a single bolt.
I found that the bag was a bit flimsy when installed so I used a couple of flat bars inside the bags. These can be seen in the image running up and down inside the bag. I didn't have time to paint these. Unlike some mounting designs I have seen online in which the nuts are inside the bag, I use stainless nylon locknuts outside the bag so the bolts extending through the nuts would not damage items placed in the bags. The arrangement ended up being solid and the bags work great.
If anyone is interested, I could provide dimensions or additional images of the brackets.