On Tuesday, March 12, 2019 at 8:46:50 PM UTC-5, Frank Krygowski wrote:

I guess we could do a poll. How many here have had a road bike rim fail
by having the brakes eat through it?

- Frank Krygowski

I have had this problem on my folding commuter bikes, particularly the one that I use in the winter. It was always the rear wheel. My hypothesis was that the front wheel was lofting abrasive dust and slush which somehow landed on the rear wheel's braking surface. I solved the problem by converting the bike to a "roller" brake. I haven't replaced a rim on that bike in several thousand miles now. Before the conversion, I'd get about 2,000 miles on a rim before it would begin to "thump" under braking. NB: I'm a heavy user of the front brake.

There's a different sort of problem on my "good weather" folder, which I can't fit with a roller brake. After about 6,500 miles, I have just worn out my third rim. The first two had brake track wear that seemed to propagate into the center of the rim just under the rim strip. After I installed the third identical rim (Kinetix Comp 406-14), I intentionally used the rear brake *less*. After about 2,000 miles... thump, thump, thump. I took the tire off and found the rim split, but *without* the brake track wear.

I've come to the conclusion that the rim(s) were too narrow for the relatively wide (406-47) tires I've been running. I'm about to re-build the wheel with a wider (406-22) rim similar to the ones that have survived for years on my winter bike.
Steve