Originally posted by roadbuzz
What should I look for when checking for impending failure... there's nothing obvious, but that doesn't always mean much. Are there any rules of thumb re/life expectancy?
My opinion is that if they are properly designed and made, rims should wear from the brake track wearing out. Since riding conditions and pad/rim combinations vary, the only way to be sure is to see how much material is actually there. Without calipers, I don't know how you'd measure this accurately with clincher rims. I wouldn't worry about it unless you can feel a lot of concavity )_( with your fingers.
From what I have seen, with modern rims, it's more likely that they will fail at the eyelets long before the brake track.