This is a larger gear mounting plate I designed for my Lectric Xpedition ebike, used to strap gear on to. You can also mount bottle cages on top of this as well, if you have bolts long enough. I believe this will work on any bike with three pack (three-pack?) mounts.
FreeCAD files included if you want to tweak it and make it your own. Happy riding!
The author marked this model as their own original creation.