Compression plug

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macinblack
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Compression plug

Post by macinblack »

I'm new to carbon forks and so after some extended judder I have checked the headset and noticed that the compression plug has raised its ugly head above the steerer.

Image

I've had a quick google and none of the posts I've seen feature this form of plug.

What's the correct way to reinsert it please?
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fatbikephil
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Re: Compression plug

Post by fatbikephil »

Is it an expander plug with a bigger hex socket to tighten it into the steerer? Usually a 6mm with the smaller M5 bolt that preloads the headset screwing into this.
A bit of friction paste on the bung will help keep it in place without having to tighten it too much.
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faustus
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Re: Compression plug

Post by faustus »

Always a joy. Try find a bung with a long clamping surface, and as Phil says, use plenty of paste.
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macinblack
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Re: Compression plug

Post by macinblack »

[urlImage][/url]

It's this style. I should mention that it seems quite well held, what's the best way to loosen it?

Cheers, Mac.
Hyppy
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Re: Compression plug

Post by Hyppy »

macinblack wrote: Mon Jun 09, 2025 8:11 pm what's the best way to loosen it?
Undoing the same outer hex Phil mentions. I find that sometimes you need to angle the hex key a little once inserted—and so with it the plug—to force it to grip the steerer and stop the whole thing from rotating.
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fatbikephil
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Re: Compression plug

Post by fatbikephil »

macinblack wrote: Mon Jun 09, 2025 8:11 pm [urlImage][/url]

It's this style. I should mention that it seems quite well held, what's the best way to loosen it?

Cheers, Mac.
That looks lie a couple of flats to get a big open ended spanner on to unloosen rather than an allen key?
Hyppy
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Re: Compression plug

Post by Hyppy »

fatbikephil wrote: Mon Jun 09, 2025 9:56 pm
macinblack wrote: Mon Jun 09, 2025 8:11 pm [urlImage][/url]

It's this style. I should mention that it seems quite well held, what's the best way to loosen it?

Cheers, Mac.
That looks lie a couple of flats to get a big open ended spanner on to unloosen rather than an allen key?
Ah! Quite coincidently I had to tighten up mine yesterday which looks the same, and never thought to use the flats: I reckon they're just to stop it rotating as per earlier post and it's still an Allen key job.
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macinblack
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Re: Compression plug

Post by macinblack »

I think so, the rounded edges sit on top of the steerer. Just wanted to check before applying any force.
redefined_cycles
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Re: Compression plug

Post by redefined_cycles »

macinblack wrote: Mon Jun 09, 2025 10:36 pm I think so, the rounded edges sit on top of the steerer. Just wanted to check before applying any force.
Yes Mac. Indeed the lip at the top of the bung sits above the carbon steerer tube. The better squared (or whatever the word is for a perfect 90 degree angle on a round tube, if you know what I mean) you have the steerer tube, the more flush that bung will sit up against it.

I usually push down as well as what Phil/Hyppy said about slight sideways pressure. Remember, there is a sweet spot of torque on that bung, you don't wanna swing on it and once everything is done up nicely - including top cap etc - it all locks each other into place.

Last thing is that all bungs are not created equally. If that bung has been slipping, you might want to have a low threshold for upgrading the bung, and bunging this one away (pardon the pun).
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macinblack
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Re: Compression plug

Post by macinblack »

Thanks everybody - Tools out, so to speak, in the morning. :-bd
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