Thanks for the Pics MS1700, it looks like I did pretty much what you did only I used the original Harley mount under the tourpac which is chrome steel.
I do not carry riders, so I wanted to have the Tour-pac sit further forward and not so much hanging over the rear fender.
You are correct in that steel is better than aluminum for the bolts to screw onto. I used 5/16 SAE
threads for the 1/2 inch of steel and just screw the original metric bolts back in the sissy bar.
I could lower the Tour-pac by a couple of inches and still have clearance
and I may end up doing that.
What I had in mind was to be able to dismount the tourpac and change back to the sissy bar in about five minutes and it worked out beautifully, I can change into the tourpac in a matter of minutes.
I intend to use the Harley tourpac only whenever I go on overniters and the sissy bar the rest of the time. I had the tourpac on my 1100 and it worked fine on that bike.
One thing though, I just use two bolts instead of four as you don't need four bolts for the tourpac or the sissy bar and with the close proximity of the fender on the lower bolts you end up fidding around trying to get those lower bolts started in the threads.
I forgot to take pictures of the brackets before I put the tourpac on, but I will take some when I take it off again tomorrow or next day.
I used two flat pieces of steel welded together for rigidity, then heated that and put it in a press and to get the curve in the brackets, then welded a top plate of 1/4 inch steel and that ties the curved bracket together. Then I bolted the base of the tourpac to that.
I'll just store the tourpac in the garage until I get ready for it.
I got the second set of new fatty crash bars on today too, I'm keeping the road hot between Motorcycle Superstore and my house with ordering two sets of fatty crash bars in less than two weeks! And for the same bike no less. While I was at it I ordered a front fender rail and eagle ornament, so my brand new crashed roadie is coming right along.
I might even have time to ride between putting on clap ons.
Clap on, clap off.