Threadless headset shannigans

[MrGrumpy]

Ok Son no2 decided that it would be good idea to take the stem and handle bar of his BMX however when I saw what he had done I flipped . The stem bolt ( one in the middle ) has been stripped to the point that it wil not grip the middle nut/washer inside the fork crown. Now I was thinking yes no probs I can knock out the star fangled washer thingy but it is one of those that has been spot welded inside?? Also there is a spacer that fits into the top crown race which has split and thus I cannot get the fork crown and the headtube to sit nice and tight! Anyway question is this does this centre nut need to be tight? I`m thinking might get away with a repair of the threads and new bolt (along with a new washer for the top crown race)

 

[accountantpete]

1. The star nut inside the steerer/top cap/bolt just draw up the forks so that the stem can positioned correctly and then tightened up - and it is the grip of the stem which holds things together. So the easy solution if I read it correctly is to get another bolt - even if this is just a temporary measure to get the forks into position.

2. The split ring washer usually goes at the top - so you have the cup, then the bearing on top and then the washer.

3. With some headsets it can all seem to be not fitting that well until you tighten things up with the top cap bolt - so I'd sort out 1 and then give it a go.

 

[MrGrumpy]

hmm so the washer is meant to be split?? Ok shall try another bolt my fear is that the star nut inside is boogered but its not that easy to remove, well from what i can see as it looks like its welded in!

 

[RecordAceFromNew]

hmm so the washer is meant to be split?? Ok shall try another bolt my fear is that the star nut inside is boogered but its not that easy to remove, well from what i can see as it looks like its welded in!

If the stem bolt is stripped as Pete said you can just use another bolt, if the star nut is stripped if there is enough space for another one on top you can knock a new one in.

 

[accountantpete]

hmm so the washer is meant to be split?? Ok shall try another bolt my fear is that the star nut inside is boogered but its not that easy to remove, well from what i can see as it looks like its welded in!

If there is space you can always wedge another inside.

 

[Tim Hall]

Or just preload the bearings by leaning heavily on the bars while you do up the pinch bolts.

 

[P.H]

You need something to compress the bearings to get the correct fit, then tighten the stem. Once this is done it's the stem holding it together and whatever method was used to get the correct compression becomes redundant. It's probably the misunderstanding of this that led to the thread getting stripped, I've seen it a number of times where people have tightened the bolt without loosening the stem.
Anyway, bit of imagination and you'll see there's several possibilities.
Heres one - drill through the existing welded star nut*, use a length of threaded rod with something acting as a washer either end, simply tighten with a nut each end.

* I have my doubts that it is welded, I can't see any advantage to doing so.

 

[fossyant]

Big hammer - always works

 

[MrGrumpy]

You need something to compress the bearings to get the correct fit, then tighten the stem. Once this is done it's the stem holding it together and whatever method was used to get the correct compression becomes redundant. It's probably the misunderstanding of this that led to the thread getting stripped, I've seen it a number of times where people have tightened the bolt without loosening the stem.
Anyway, bit of imagination and you'll see there's several possibilities.
Heres one - drill through the existing welded star nut*, use a length of threaded rod with something acting as a washer either end, simply tighten with a nut each end.

* I have my doubts that it is welded, I can't see any advantage to doing so.

I can assure you that the washer is welded in, however having access to some taps has allowed me to run a 12mm tap through the hole and I found a new 12mm threaded bolt in our scrap box so all is well in the world Managed to repair the existing hollow bolt by running a tap down it but not convinced it would hold tightening it up!

 

[Pat "5mph"]

Ok, this came off this

How do I put it back in? Hammer? Right into the bottom part of the headset, or stop at the top "fatter part"? Greased?
Guess you cannot adjust the height of that kind of headset, eh?
I understand it's a threaded headset, but I did not think it warrants starting a new thread
Thank you for your help!

 

[youngoldbloke]

That looks like the wedge from the bottom of a quill stem. There should be a long threaded bolt too that tightens it against the angled base of the stem - see sheldon brown. Yes (the stem) is height adjustable.

 

[Pat "5mph"]

That looks like the wedge from the bottom of a quill stem. There should be a long threaded bolt too that tightens it against the angled base of the stem - see sheldon brown. Yes (the stem) is height adjustable.

Yes, got the bolt too, gonna go see sheldon again, saw him yesterday already but did not know I had a quill stem.
Thank you!

 

[Pat "5mph"]

Aha, I see now! I was doing it all wrong Got the minimum insertion mark too, won't have to guess it.
Cheers for that!