I have some Transit Epic panniers (from Performance) that are largely a good set for credit card touring. However, even when tightened as much as possible, a good bump will knock one or the other loose-very frustrating especially given how difficult they can be to install or remove. I secure mine with a tie wrap or two placed diagonaly or criss-crossed over at least one of the top hooks (usually it's the front that comes loose). Although this system works, it's not practical if you remove them daily, of course over 4 day of touring I never remove them.