shortening steering tube carbon

knobstop

Hi
im trying to shorten my steering tube by one spacer.
i have all the cutting tools i need and measurements but im stuck.
i have remobe the centre allen key bolt but where i want to cut the internal
part that the allen key bolt goes into is in the way, could someone please tell me
how to move this.
many tnx

bobones

If it's an expanding bung (as it should be on a carbon steerer) like this

then you can unscrew the top with a large hex key (8mm I think), which will loosen the wedge at the bottom of the bung so that you can pull it out. You may need to give it a tap to release the wedge. If you loosen it too much then the wedge may fall into the steering tube.

If it's a star nut (which really shouldn't be used on carbon steerers) then you can knock it down a little by inserting a suitable screwdriver into the middle screw hole and tapping the handle with a hammer.

knobstop

I will post a photo at lunch so you can tell me what type i have tnx

knobstop

Ok keeps saying file is too big.
ive taken the normal first allen bolt out and inside the thread hole is another allen hole so i assume its like u said i have the one in the picture tnx.
also does it matter on the exact location of this when i put back together?

keef66

My guess is it should really sit in the steerer at the point where the stem is clamping it.

On my Scott the bung won't go right down into the steerer; it has a lip and so sits right at the top of the steerer tube. Scott say you can't have more than 5mm spacers above the stem, presumably so the stem is clamping the steerer where it's supported internally by the bung.

g00se

You can get different types of bung. Some sit with a lip over the top of the steerer - this dictates where te stem can clamp. For this reason - I guess - these types of bung can be quite long:



Some you place where you need to and tighten down into it - more like a star nut:



Alternatively - you can glue a metal tube into the steerer and use a star nut