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I opened up my FSA BB30 bottom bracket to find metal shavings all around. I opened up the bracket to try to find the source of a creaking sound, I’m guessing this is it - but I’m not quite sure what to fix/replace based on the metal shavings.

metal shavings before cleaning

bottom bracket and bearings after cleaning area

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    First look to see if the bearings are all there. If not then they probably ate themselves. But this could be shavings that fell down the seat tube, as someone was trying to make a seat post fit or some such.
    – Daniel R Hicks
    Jul 17, 2018 at 22:39
  • @DanielRHicks thanks! So buy a BB30 bearing removal tool to check out the bearings? Something like this? amazon.com/dp/B00426ENBU/ref=cm_sw_r_sms_c_api_ubNtBbDKXZ86Q
    – dpollitt
    Jul 17, 2018 at 22:43
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    If the bearings are intact then it seems unlikely that they're the source of the shavings.
    – Daniel R Hicks
    Jul 17, 2018 at 22:49
  • @DanielRHicks I think your frame shavings from a drilled out hole is a real good theory. Doesn’t explain my BB creak, but does seem unrelated based on your theory. Probably will pull the bearings anyways to find the creak :)
    – dpollitt
    Jul 17, 2018 at 22:52
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    Metal shavings are obviously chips from a cutting tool. They seem to be the same metal as the frame They actually may have gotten there during frame prep stage of assembly - perhaps from bottom bracket shell or sear tube reaming.
    – Argenti Apparatus
    Jul 17, 2018 at 23:52

1 Answer 1

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Some possibilities:

  • The seat tube or theoretically the head tube was reamed after the bottom bracket was installed, either at the factory or during assembly or service.
  • A little deposit of cuttings somehow got lodged in the seat tube or down tube from any of the many manufacturing steps that could create them, perhaps sticking to the inside of the tube with the help of some cutting fluid, and they made it all the way through the process but came loose over time once the bike started being ridden.
  • Some kind of simple brain fart, or laziness, or apathy, or some combination thereof on the part of whoever reamed the shell or seattube or assemeble the BB/cranks at the factory.
  • One corner case scenario that's theoretically possible with all cartridge bearing bike components is the bearing seizes due to extreme wear, alignment, fit, and/or quality issues (maybe some other factors too) and the spindle, axle, or bearing bore they're supposed to have stationary contact with is now a dynamic contact, which will start wearing away material, in this case from the crank spindle. If something like that did happen here I'd have no idea how the material got lost in such a shaving-like way, but I've seen weirder

It's not necessarily connected to the creak in any way. BB30 is simply prone to creaks.

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