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I found this 'scratch' on my carbon frame on top of the front derailleur. Not quite sure when or how it appeared. Could this be more than a scratch?

enter image description here

enter image description here

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That's just a light scratch. No issues.

if you are worried that the carbon-fiber composite has been damaged by an impact or scratch, the abrasion is far too shallow for that. It has not even penetrated through the paint.

It's not a crack because cracks do no start in the middle of frame tubes, they propagate from edges or holes.

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    I've written a comment on Rough Manly's answer in response to it getting low-quality flagged. It would be unfair of me to not comment here, I think there should be some form of evidence offered to the OP on why you've made this conclusion via an edit. Imagine they don't have your x-ray vision; even if there is a strong consensus among commenters they're left relying on your say-so
    – Swifty
    May 5 '20 at 17:01
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    @Swifty This is fair, updated the answer. May 5 '20 at 17:15
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    phew taken like a champ lol, +1
    – Swifty
    May 5 '20 at 17:47
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    @Swifty i don't mind constructive feedback and being kept honest May 5 '20 at 18:10
  • It's not a crack because cracks do no start in the middle of frame tubes Nit pick - they do when you're t-boned by a car blasting through a crosswalk at 40+ mph/60+ kph. :-/ May 6 '20 at 2:20
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If you saw my Stevens Team Carbon cyclocross frame you'd feel much better.

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    We should compare scars, I have not been kind to my 2011 Scott Spark MTB. Had a moemnt when the headset area was creaking and groaning that had be worried, but turned out it was a shifter cable ferrel.
    – mattnz
    May 5 '20 at 5:02
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    This could be made into a very useful answer by including a picture of some of the more severe scratches. This would help inexperienced bike users to get a better feeling for what is and isn't a worrisome damage.
    – Emil
    May 5 '20 at 7:38
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It's very unlikely to be a crack because it is the same width throughout (cracks tend to be wider in the centre, or at least irregular width) and because it is straight, not jagged.

The shallow depth is also a clue that it is a scratch. You can shine a focussed flashlight into it and see if it reflects from the bottom. If it does, then a scratch is the likely explanation. A crack's ratio of depth to width is much larger, so it looks darker in the centre.

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Its a scratch you shouldn't be worried about it

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  • Welcome to the site. Do please take the moment to browse the tour to learn how SE is a little unusual, as a Q&A site.
    – Criggie
    May 5 '20 at 11:57
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    Welcome Rough. This did get flagged up, I'm not sure if because it's so short or if because it says the same as an existing answer, which is also very short. Normally answers should have a bit more detail, so if there's more to add then feel free to edit in some further detail if it's relevant, or supporting evidence for why you have made this conclusion; imagine you're in the asker's shoes and you don't know how to judge for yourself.
    – Swifty
    May 5 '20 at 16:58

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