I have the chainring shown below. It's the front sprocket of an ebike. Does this chainring need replacing or are the teeth still OK?

enter image description here

  • One test you can do is to attempt to pull the chain away from the sprocket near the front. If you can pull the chain far enough that it's almost to the top of the closest tooth then either the chain or sprocket (or both) is at end of life. Oct 14, 2018 at 0:25
  • Perfectly OK but rather dirty.
    – Carel
    Oct 14, 2018 at 18:12

2 Answers 2


Shows some wear, but looks OK.

All teeth look symmetrical and so do the spaces between them. Really worn teeth look like a swept back shark dorsal fin or develop a visible burr.

Do a Google image search for 'worn chainring teeth' and you'll get plenty of examples.

  • 1
    That said, a chainring is cheap and if you have it apart now you might as well replace it now.
    – RoboKaren
    Oct 13, 2018 at 19:22
  • 4
    Definitely needs cleaning Oct 13, 2018 at 19:26
  • @RoboKaren Are ebike chainrings as cheap as regular ones? Oct 13, 2018 at 19:48
  • Like it’s around $20: motostrano.com/SRAM-PC-EX1-8-speed-Chain-Motostrano-com-p/…
    – RoboKaren
    Oct 13, 2018 at 20:16
  • 1
    I'd clean and refit it, should last for at least one more full chain. Depends on your cost of labour, the value of your time.
    – Criggie
    Oct 13, 2018 at 22:40

Although the texture appears to be rusted/worn, the actual chainring itself seems to be okay. As someone said, the teeth are symmetrical as are the spaces in between each one. If this is the case, then you should be all good.

  • Hello, this is a very informative answer. Unfortunately, it doesn't offer any additional information beyond what has already been posted and accepted as an answer. Stack Exchange is designed to accumulate quality, distinct answers, so posting a duplicate answer is contrary to the mission of SE. Oct 18, 2018 at 14:16

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