On Saturday, 28 September 2019 12:00:41 UTC-4, AMuzi wrote:
On 9/28/2019 9:06 AM, Frank Krygowski wrote:
On Saturday, September 28, 2019 at 8:51:31 AM UTC-4, wrote:
Thank you for the further input, jbeattie, John, David, AMuzi and Tosspot. I squeezed the sides of the braking surface, and the rim seems solid.

Is there a rule of thumb for minimum safe rim thickness at the braking surfaces?

- Frank Krygowski

Yes.
Go this far:
http://www.yellowjersey.org/photosfr...st/wornrim.jpg

and then reverse the wear a little.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

That looks like the used Matrix rim I had that recently failed!

Cheers