Strange Bung

[DODDY]

So, the new carbon Alpina (second hand) ebay forks have arrived! They are as good as new. I take off the dedaelementi top cap and underneath is an M6 female thread in an aluminium bung. Nothing strange so far. The thread is in the bottom of a 8mm A/F female hex pocket. If I undo this bung using an 8mm allen key I can then withdraw the bung. It has on the underside an M12 male thread that has been fixing the assembly to what is left in the steerer.

Inside the steerer is an M12 female thread in another aluminium billet that has been split along its length in four positions. Now this part is not very thick, I would suggest only about 8mm and looks like it has been driven into the steerer down to a pre-machined shoulder. There is nothing I can see 'expanding' this part and nothing I can see retaining this part but it is in there good and hard!!!

Any idea what this type of bung is???

Cheers
CRAIG

 

[youngoldbloke]

Photos please! If it has a Deda top cap it may be a Deda plug, but it is (obviously) very easy to change the top cap. If the part left inside is firmly fixed it may be one of the 'glue in' variety.

 

[DODDY]

Sorry, no photographs available at the moment. Is glueing in the bung thread a common practice.

Back to an earlier question............... If the bung is glued in could I use this as a basis to 'extend' my steerer by 25mm????

 

[youngoldbloke]

Sorry, no photographs available at the moment. Is glueing in the bung thread a common practice.

Back to an earlier question............... If the bung is glued in could I use this as a basis to 'extend' my steerer by 25mm????

Not common. 3T make such a system apparently. There are quite a few different plugs out there, some longer and more complex than others. As to the wisdom of extending - I have no idea! - but a gut feeling that it is probably unwise. Can't you flip your stem to gain height?

 

[DODDY]

Unfortunatly the steerer is about 12mm under the top of the stem without any collars

 

[youngoldbloke]

- oh dear ...... your head tube too long then (sorry if I'm stating the obvious!)?

 

[DODDY]

Yep!

I am going to give it a great deal of thought tonight and try the forks for size. As yet its all theory They may not be as bad as first stated, but I am preparing myself for worst cases. I think I will have to extend the steerer somehow!!!!!