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    Badly worn BB from derailleur cable

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    18 Comments

    1. Ramoutarb on

      How the hell does a derailleur cable do this? How frequently are you shifting? Lmao I’m picturing you shifting so fast and frequently that the shifts never complete

    4. Tomac_123 on

      Could it be from movement of the suspension? Every time the rear moves, the cable housing rubbed a bit?

    5. Sir_Ronald_Bont_III on

      https://www.easycomposites.co.uk/black-epoxy-repair-filler

      Similar issue a few years back on a road bike carbon frame seatstay from a mudguard essentially trying to hack through it. Wore a deep groove into the stay.

      After seeking advice with detailed pics, ended up using EF1 2-part epoxy repair filler.

      Still going strong now.

      BUT that’s my situation and this may need a carbon filler reinforcement added as well as I see it’s broke through in one area. I’d imagine the thickness of the remainder of the groove is <1mm.

      I’d say it’s repairable but to echo the comments of others, would preferably like to see more pictures

    7. Big-Don-Kedic on

      Honestly, I’d fill it with epoxy and send it. You can probably have someone do an actual composite repair with a patch so it holds it together better, but I wouldn’t worry too much at this location.

    13. SmellyButtFarts69 on

      So my Commencal FS bike did this. It didn’t make it quite all the way through, but it was similarly deep. I had probably been riding it for a year or less when I noticed it.

      I covered it with a piece of tape and it never came back. Wild how a piece of gorilla tape is somehow more resilient than a chunk of metal, but apparently it’s a thing.

      I put a 180 fork on it and it has survived multiple seasons as my downhill bike.

      YMMV but I think it’s a good indicator that this is not as bad as it looks. There’s no crack, no dent, no material has been bent/pushed/pulled. It is across the BB, so it’s weakening it perpendicular to the direction of travel…I just don’t think it’s going to break. The stresses on that short, stout piece of tube in that direction cannot be that high.

      I say send it.

      Right after you file the sharp bits and tape it, anyway…

    14. ronniearnold on

      Just curious, do you WANT to ride on this? A broken back would be WAY worse than getting this replaced/fixed.

      Good luck…

    15. badger906 on

      I’ve seen this a few times in my frame painting days. Realistically the frames fine. It’s not going to fail. i tend to fibre glass body fill it, sand and paint. Good as new

    18. mikebikema on

      I don’t know why people are buying carbon fiber frames AL is the way to go only time is if you were a professional racer and the bike was given to you for free

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