OK... this thread title caught my attention...

My beautiful new baby had her first hiccup this last week - in the biggest gear (big front chain ring, smallest rear cog) it would click on my down stroke...

First we thought the derailleurs... but fiddling with those sorted nothing... hmmm, bent chain ring? Into the shed and three of us peering, finding that the chain consistently misses the ring in the same place - must be a slight bend in the chain, right?

Spanners out, trying to straighten the suspected link even though it looks straight... aha... but whats this??? The tooth on the big ring... ah yes... its twisted and chipped....

So my partner fabricates a tool to straighten the tip of the tooth... and away she is... changing as smoothly as a hot knife cuts through butter... sweeeeet