Smart. I'm considering your approach but I've a couple of concerns. I don't doubt that the bag is secure but with all the jostling attendant to riding on rough roads does the assembly rattle about to the point of distraction? Further, the bag intended for this modification is a discontinued Cardiff Trowbridge (think Carradice Barley) which doubles quite nicely as a walkabout day bag when a shoulder strap is attached. I wonder if the boat cleat's obtrusiveness make it awkward. Anyone else try this mod and have any insights?