If your chainring teeth look more “pointy” or sharp than they should be or look blunted and smaller than they should be then the chainring is starting to get worn. If you are having difficulties with setting up indexing to work consistently that you didn’t have when the chainset was new – then it may be time to replace it. It’s always best to change stuff at the first sign of trouble on your distance bike
Audaxing 
In an effort to prolong the life of my chainrings and sprockets I’ve been changing my chain every time the chain wear indicator gets to .75%. Apparently if gets to 1.00% you end up having to change the sprockets and/or chainring due to the wear the stretched chain causes on them.
I’m finding that I have to change the chain about every 2000 km (chains about £12 a pop for a Shimano CN-5701) and so far every things been working smoothly. Of course eventually the sprockets/chainrings will need changing but the idea is to put this off for a much longer period.
The other school of thought is not to change anything until you get shifting issues etc. and then change the whole drivetrain, but this seems a bit too risky for Audax…….
By: markysparks on April 23, 2014
at 10:29 am
I use a chain wear checker too ( see https://audaxing.wordpress.com/2012/12/30/100-mile-ride-didnt-go-well/ ) It’s my impression that chainrings wear so slowly that they are not influenced by the chain
By: audaxing on April 23, 2014
at 1:56 pm