I don't have a Scrambler much less the solo seat with the mini rack but I have a stock T100 Bonneville seat with the grab rail.
Here is my suggestion for something to try. I think this method of mounting basically any tail pack would work with the mini rack that you have:
The first thing I would do is get some straps. I use the Rok Straps. I like the one that is a combo bungie with a strap that can be cynched down. The bungie piece of it is not like the cheesy round bungies you get at the hardware store but is a flat strap shaped bungie that is seriously strong. I don't care for round bungies or bungie hooks as they can slide around and loosen the load. Two Rok Straps looped around the rear of your mini rack and then around another part of the frame forward should secure your pack.
I use the dresser bar that the grab rail mounts to to loop two straps around. I offset them so that they pull against one another and center the load. With your mini rack and the partitions in it, your load witll be even more secure. Loop the front of the strap around a forward part of the frame. The top part of where the rear shock fasten to the frame works good.
Get a bag or pack that has loops in the top that you can thread your straps through. Here is what mine looks like:
With the rock straps, this load is extremely solid and does not budge even a 1/20 of 1".
I will try and get you better pictures later showing the fastening points.
Here is the link to the Rok Straps model # I think works really well:
[ This message was edited by: ChuckofTahoe on 2006-08-14 23:33 ]