I think you can get a hard case that mounts to the rear. That would work well for your shoes, and then you could lock your helmet in it so you dont have to carry it in with you. Or have some dumb ass gun lock like I use for my helmetThe free bag work's great for carrying my shoe's on the commute to work.
Ya .. the case's are coming .. just gotta save up the $$ first. Till then the free bag will work fine for the little stuff. It an over the shoulder bag and it has a zipper slot on the top for the handle to tuck in but I just flip it over and slide it over the triple tail. It will do now.