Carbon steerer tube - bulge preventing removal

darjeeling

I was trying to check my carbon steerer tube for cracks. However, the tube has bulged out slightly where the internal headset plug sits, so it can't be pulled out through the spacers & headset cups.

The headset is a Chris King threadless ('NoThreadSet'), but seems to have been fitted with non-standard internal parts. Instead of the expected star nut, there's a plug of some kind, and an alloy cup screws down into that (see photos).



I was wondering if anyone here has come across this kind of headset setup before. Also, does anyone know if a bulge in a carbon steerer tube is a cause for concern, and how I might go about pulling the tube out?

Thanks!

[EDIT]
The internal plug seems to be an Oval headset expander.

victorcarrera

Seems that the wrong size plug was inserted, over tightened or that the plug is expanding against the spacers(steerer length was cut short or incorrect spacer height).
Unscrew the expanding bolt in the steering tube and you might be able to remove the plug - unlikely because the plug is probably embedded in the steerer. (A long screw with the same thread might be able to shift the plug when it when it is not in compression)
If you are sure the steerer is damaged even slightly, push it down as far as you can and try to get enough room at the bottom cut it off and replace or cut through one of the spacers that you think is below the plug.
Sounds like an extreme situation and star nuts only in aluminium steerers.
If you are not 100% sure of your fork assembly I suggest you take it to someone who is.

darjeeling

victorcarrera wrote: »

star nuts only in aluminium steerers.

Thanks - I didn't know that, though now I think of it my last bike also had a carbon steerer with a similar plug.

victorcarrera wrote: »

Seems that the wrong size plug was inserted, over tightened or that the plug is expanding against the spacers(steerer length was cut short or incorrect spacer height).

[...]

If you are not 100% sure of your fork assembly I suggest you take it to someone who is.

Yes, it looks as though one or other has happened.

After posting here this morning, I mailed the company that made and assembled the bike, and had a reply asking for photos, and recommending not to use the bike until getting it checked out, so I shall do that.

The photo below, which I've sent on, shows the steerer with a slight bulge around 3cm from the top.

victorcarrera

Does the stem clamp have a cut out that would line up with the bulge? I have only ever seen them fitted to aluminium steerers. (BBB and Pro Lite mostly).

darjeeling

victorcarrera wrote: »

Does the stem clamp have a cut out that would line up with the bulge? I have only ever seen them fitted to aluminium steerers. (BBB and Pro Lite mostly).

It doesn't have a cut-out, no. Reassembled it looks like this:

darjeeling

The outcome of the story is that, having seen the photos, the company that made the bike have asked me to post the fork to them for a replacement. I'll probably go with that option for now, but may eventually put a steel fork on the bike so that it's all steel.