Headset loose Steerer Fork Bung

harringtonp

I have a little play in my headset even though I have replaced the bearings recently and cleaned it out.

What seems to happen is that when I tighten the headset cap bolt the steerer fork bung lifts a little as shown in the first image.

I can push it down again but am wondering why it lifts in the first place ? How tight should the star nut be that the bolt goes in to (I have it fairly tight) ? As an aside I notice that I can't loosen the star nut completely it just keeps turning, I presume this is normal.

Basically I am wondering is the bung broken or am I doing something wrong. A replacement could be bought at

https://www.planetx.co.uk/i/q/FSPXFBUMK2/planet-x-carbon-steerer-fork-bung-mk-2

if necessary but how would you get the original out in this case ?

Cee-Jay-Cee

The exact same thing started happening on my bike after replacing the headset. I bought a new steerer bung and it solved the problem.

I’m not sure about the PX bung you linked to, I’d be going for something with a more knurled surface to increase grip. The bung I replaced had very fine cross hatching which simply didn’t offer enough grip on the inside of the steerer despite me using a load of carbon paste with it.

harringtonp

Cee-Jay-Cee wrote: »

The exact same thing started happening on my bike after replacing the headset. I bought a new steerer bung and it solved the problem.

I’m not sure about the PX bung you linked to, I’d be going for something with a more knurled surface to increase grip. The bung I replaced had very fine cross hatching which simply didn’t offer enough grip on the inside of the steerer despite me using a load of carbon paste with it.

How did you get the old bung out, just grip the top with a pliers and pull ?

I see the Planet X replacement is out of stock, I presume these are fairly standard components. Am wondering would

https://www.chainreactioncycles.com/ie/en/deda-elementi-expander-bung/rp-prod166220

be compatible and what the 28.6x23 refers to on the current bung ?

harringtonp

Looking at

https://www.youtube.com/watch?v=aBjJ35B-Og0

it would seem that in theory it is just a case of loosening the nut and the bung should pop out. I have the bike since 2009 (winter bike last few years) so it may not be this easy.

I get the impression from reading that I should probably buy and try carbon paste on the existing bung before purchasing a new one as there may not be anything wrong with it.

Cee-Jay-Cee

harringtonp wrote: »

How did you get the old bung out, just grip the top with a pliers and pull ?

I see the Planet X replacement is out of stock, I presume these are fairly standard components. Am wondering would

https://www.chainreactioncycles.com/ie/en/deda-elementi-expander-bung/rp-prod166220

be compatible and what the 28.6x23 refers to on the current bung ?

I'm not sure about the bung in your bike but with the one on my bike I used a 3mm allen key which inserts down into the bung and contracts the sides of the knurled barrel which in turn allows it to be removed. If you look at the picture of yours there is an allen key slot at the top but there should also be one further down into the bung (the top one looks like 5 or 6mm so try a 3mm or 4mm allen key down into the bung and see if it loosens it.

harringtonp

It came out without much trouble in the end, just loosened the screw. Fell apart in the process but the bottom bit could be shook out of the fork easy enough.

The bottom black cap seems to have a bit broken off (see last photo) which looks like it locked the metal tube in place while tightening. I think this may have been the problem.

Anyhow for now got it in tight and the cap bolt does not seem to be pulling the bung up.

If it goes again, I know what to order. Read reviews and like the sound and price of

https://www.chainreactioncycles.com/ie/en/brand-x-headset-compression-device-carbon-cap/rp-prod130961