Stuck expander/compression bung

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  • Cant really explain it in words but the bottom bit of the bung is stuck in the steerer tube, the top bit comes out just not the the bottom bit.

    can anybody help remedy this?

  • pictures

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  • can anybody help remedy this?

    Looks like the collet that expands the bung is still the bung. So the bung is stuck in its 'expanded' state. Try threading a bolt in to it - just a few threads - and then 'convincing' it to come out. Which might involve a rubber mallet and some gentle taps....

  • how do i tap it out? i dont understand, sorry for sounding dumb.

  • OK - the bungs usually work buy pulling a cone shaped collar up in to a metal tube, expanding the tube and then gripping the steerer. Because the tube is divided in to four quarters, held together by a rubber band / o-ring that raps around it, it expands as the cone moves in to it.

    What you need to do is push the cone down and out of the tube, which will allow the tube to contract and reduce the pressure on the walls of the steerer, and then be released.

    To do this, try screwing that thing in your hand back in to the bung a few threads , then give it a gentle tap with a rubber mallet. I assume its the larger of the two threads that screws in to the bung.

  • So tap it into the tube?

  • Ang on, I've got one kicking around, I'll take a photo or somn'.

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  • So yes, you see the black cone on the base of the bung in my photo? On yours, that's stuck inside the metal tube.

    You need to screw the thing in your hand back in, partially, in to the cone, then tap the whole thing down towards the fork crown with a rubber mallet. This will push the cone down, out of the metal tube, and free the tube.

    Or just set the thing on fire

  • thanks makes sense now, Ronson lighter fluid?

  • I have a specialized expander bung that I hoped would lift out serenely when I released this screw, but it appears to be stuck.

    Should I bang it with a hammer?

    Edit: banged it harder and something happened. Hopefully not catastrophic.

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  • It's one of these. Don't bang it with a hammer it won't budge. I had one so tight it made the stem harder to slide off despite using the recommended 9nm on installation. I took it to a bike shop and they hit it with a hammer 😕
    I don't know whether this is a good or bad design but at least they're secure. I kept the instructions so i don't forget and end up fucking it.

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  • There's a YouTube vid with a neat way to remove that specialized bung

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Stuck expander/compression bung

Posted by Avatar for badmanlongtime @badmanlongtime