I seem to have stripped the threads on the front forks of my old Dahon made folding bike..It takes an old style conventional headset..1 and 1/8 inch and the handlebar post fits in and a wedge is tightened. Is there any way that the threads on the fork steerer tube be repaired. A friend of mine has suggested the only way is to get a welder to fill in the threads with a braze and recut the threads..Is this the only way to fix the threads?
The other alternative is to buy an old bike with similar forks and fit them?

I'd get another fork. The last thing you want is a patch job to fail during a ride.

I have tried some studlock..a bit like loctite..and I have tried a different thinner headset so the nuts are slightly lower down the steerer tube on good threads.Seems firm now..and will go gently over the next few days..If no good..will go for an old pair of forks..

There is but do you want to pay Machine shop rates ?

You Know I cannot see a thing to actually be able to suggest other solutions

go with the brazing in more metal then getting it re threaded .

You might also be able to use a threadless headset with a pre-load adapter.

https://store.bikefriday.com/product...oducts_id=8137



Odd, I'm seeing an upper lockring and lower adjuster on the BF photos that I'm not seeing above. It does give a fairly tall stack height.

I wonder if I keep the adjuster that holds the ball bearings but take off the locknut and then replace that with a 28.6mm seat stem clamp that would do the job..The handlepost would then fit on top so nothing can come loose. I realise that using a seat clamp on a threaded fork is not too good but with the quill inside it there is no likelihood of anything going wrong..