Threaded Head Set

[Marchrider]

I think its called a head set. Anyway, its a 1980s steel frame bike and the threaded round tube on the top of the forks is threaded, I have tried a new nut and locknut but it just slips, it has been doing this for several years but is getting worse - it rattles alot, but I don't feel it unsafe.

I will have a chance to work on it between xmas and new year (a week off) and I am not wanting new forks, the forks are original to the bike and I am not wanting a triggers broom

any thoughts how this could be fixed ?

 

[Gunk]

Common problem is fitting the wrong size bearings, and threaded 1” headsets are not a standard size. I’ve has this problem myself, correct JIS bearings solved the play in the headset, some really useful information on the website below.

https://velo-orange.com/pages/threa...re five fairly common,inside of the head tube).

 

[Ian H]

Do you mean the headset nut works gradually loose, or it jumps the thread when you tighten it?

 

[Marchrider]

The headset is the original and worked fine for 20+ years - so I'm presuming it is the correct part.

3 or 4 years ago I noticed it was not staying tight, I marked the nut and locknut and realised it was not working loose and that it must be jumping a thread (maybe on a pot hole?)
But it has been getting progressively worse, I bought a new headset earlier this year and when I disassembled the whole thing to fit the new headset, I noticed that the problem is the threads on the round tube (that is brazed or welded onto the forks) are worn and damaged!

I don't want to bin the forks off as its part of the original bike.

 

[Gunk]

The headset is the original and worked fine for 20+ years - so I'm presuming it is the correct part.

3 or 4 years ago I noticed it was not staying tight, I marked the nut and locknut and realised it was not working loose and that it must be jumping a thread (maybe on a pot hole?)
But it has been getting progressively worse, I bought a new headset earlier this year and when I disassembled the whole thing to fit the new headset, I noticed that the problem is the threads on the round tube (that is brazed or welded onto the forks) are worn and damaged!

I don't want to bin the forks off as its part of the original bike.

There is no need to change the fork, if the headset is worn out just change the headset.

 

[Marchrider]

NO.

The problem is with the threads on the fork, the threads within the nut and lock nut are good, the damage is with the threads on the fork!

here is a picture of some similar front forks, and I have pointed to the threads that are damaged

so just to recap for clarity - the headset is OK (and I also have new unused headset) the problem exists with what the headset attaches to

 

[Ajax Bay]

If the threads on the steerer tube are no longer good enough to allow the cone and locknut to 'lock' securely, then I'm afraid it's new fork time.
I guess you could explore recutting the threads but I suspect over its many years' use you have lost some material there as well.

 

[Marchrider]

If the threads on the steerer tube are no longer good enough to allow the cone and locknut to 'lock' securely, then I'm afraid it's new fork time.
I guess you could explore recutting the threads but I suspect over its many years' use you have lost some material there as well.

indeed that is the problem, I iether need to add more material then recut it, it seems to be a very fine thread, (anyone know what it is dia & pitch?) trouble is my welding is not that good, I could distort it.
Or that metal repair paste?

 

[Gunk]

To start with I would clean and retap, then just use some loctite

 

[biggs682]

Welcome @Marchrider a good bike shop or an engineering company might be able to clean or re cut the threads up on the forks enough to use.

But more than likely it will be new forks.

Or you could get a frame builder to replace the stearer section of the forks IE the piece that is causing you an issue.

See below link https://www.woodrupcycles.com/renovations/

 

[Ian H]

3 or 4 years ago I noticed it was not staying tight, I marked the nut and locknut and realised it was not working loose and that it must be jumping a thread (maybe on a pot hole?)

This is unlikely. More likely is that the two nuts are loosening together. This is known to happen, especially if you don't have a tabbed washer between them or the tab is worn out or broken. The tabbed washer fits in the groove on the steerer-tube. Not every fork has one, but most do.

 

[Marchrider]

This is unlikely. More likely is that the two nuts are loosening together. This is known to happen, especially if you don't have a tabbed washer between them or the tab is worn out or broken. The tabbed washer fits in the groove on the steerer-tube. Not every fork has one, but most do.

I had marked them, and if they were loosening together then they must have been doing it in full rotations
in any case,when I dismantled it last xmas it was clear the threads on the stem were in poor condition,

think i will try ptfe tape or a thread lock glue - it might be enough?

does the headset matter if its loose, feels absolutely fine on normal roads - sounds hideous on cobbles, and feels annoyingly loose if I lift and carry the bike - can it suddenly become dangerous?

 

[biggs682]

With the front brake applied you should not have any rocking in the forks when you push against the brake .
And also the handlebar needs to be able to swivel without being too tight when you steer

 

[All uphill]

As someone who set off on his bike with the quillstem not tightened I'd advise against anything that might deprive you of the ability to steer.

Spoiler: I survived, but it was the worst moment I've had on a bike.

 

[Gunk]

does the headset matter if its loose, feels absolutely fine on normal roads - sounds hideous on cobbles, and feels annoyingly loose if I lift and carry the bike - can it suddenly become dangerous?

I really would not recommend riding with a loose headset, it will cause premature wear on the bearing races, if they fail it is possible that the bike will suffer from a dangerous head shake, which means that you could loose control especially at speed