Are they hard or soft bags? I have hard bags bolted onto my America with plenty of support and they have worked for over 20,000 miles.
On the other hand I bought a Suzuki fixer-upper with one-time high quality leather soft bags. But the previous owner somehow let them rub against the tire, probably after they sagged.
I would recommend very strong support because most people over load their bags. Contact with the shocks and other parts of the bike can be big problems for the bags and the bike.
