I know this has been asked several times but I'm curious if anyone can weigh in on whether these specific chainrings need replacing. They're from a triple chainring setup.
I'm replacing my chain and casette right now so it's a good time to replace the rings too if needed. But they're also pricey so don't want to chuck them prematurely.
Middle chainring was replaced about 6,000km ago. I think I ride about 70% middle ring, 25% largest ring, and 5% or less smallest ring (flat city). So I'd say the middle has had about 4,200km on it.
Largest chainring is original to bike, which has ~20,000km on it, so I'd estimate 5,000km on that ring.
Middle ring, outside (drive) side:
Middle ring, inside (non-drive) side:
Large ring, outside (drive) side:
Large ring, inside (non-drive) side:
Note: the middle chainring has a subset of teeth where the leading edge has been flattened a little bit and the dull surface finish of the metal has been worn off on the sides of the leading edge so it looks like a pronounced shark fin pattern but in fact is not that worn.
I.e. the teeth below look very worn but in fact their profile still follows the red lines. It's just hard to capture them properly on camera.