They do get rusty quick, especially when the door is beachfront. Big problem opening the door when they rust to the point of completely locking up. Periodic oiling seems to help but attracts sand so still not a good solution. A stainless steel sealed bearing roller seems like the best solution but I haven't been able to find any. Thinking about buying stainless sealed bearings and machining the groove in the outer race and replacing the cheap bearings in a new roller set.