Originally Posted by JavaMan
I keep my 9-speed chain pretty clean, and typically get about 4000 miles out of it before it needs replacing. That is, when 12 link pins measures 12 and 1/32 inch.
Tom
Me too. Over 4K miles per chain swap. I can't imagine changing it less than 2K unless you don't take care of the chain or you ride in really crappy weather.