How To Repair The Steering Head On My Motorcycle?

Having broke several on my bmx bikes yeeeeears ago headsets always worried me on motorcycles..it is one thing to fail at 20 mph but 120 is a different story
 
I don't think the old girl ever got to 120mph but I take your point.
 
One other thing to keep in mind is the original cause of failure. Although it may have taken many years to get to the current state, once you start moving metal, structurally it can be changed in a detrimental way. I would stronly consider turning up a reinforcing ring to fit around the OD, as thick as practical, depending on what type of cover fits over the bearing housing end of the head tube.

Another possible "repair", although not near the top of the list, would be to make such a ring and put a few set screws around it so they would bear on the OD of the bearing boss and put a little squeeze on things. I don't suppose you have a good way to bore that boss, do you? It could be built up in a variety of ways and bored to desired size. Or if you have TIG, you could machine it off completely and make a new insert.

Too many ways to skin this cat!
 
people put way to much trust in metal...lol

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Tony, I like the way you are thinking - sort of looking for an over engineered solution rather than a adequate and workable fix (I appreciate other might express it differently)
I do have a milling machine and it has a horizontal and vertical drive. Just giving it a quick estimation - off the top of my head - maybe the horizontal drive coupled with my boring head could machine the bearing mount.

I also have a TIG welder - while I do not feel expert enough to just go for broke - I would certainly consider welding up the mount surface and then machining back to a suitable press fit. Tony I also like your idea of a reinforcing ring - with interference fit pressed over the outside of the steering head - I have an engineer friend who might run the numbers on which material, by what dimensions to achieve a suitable (what might that be?) increase in strength. I like the idea particularly for the lower bearing - which is the really loose bearing race (so the most stretched) - The top race would seem to get substantially less impact and strain than the lower race. I guess 50 years is fifty years - I know I have stretched in certain parts of my anatomy in that time.

Thanks heaps guys.

Mal
 
I would stronly consider turning up a reinforcing ring to fit around the OD, as thick as practical, depending on what type of cover fits over the bearing housing end of the head tube.

Personally, this is the approach I would take. I don't know how loosely your bearing race fits, but if you make the ring with a substantial press fit, you may gain enough shrinkage to make that race a press fit again.

Ted
 
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Here is my scale drawing of the steering head. I am not very bright so I like pictures.

I have measured the top mount - North-South measurement 50.95 and East-West 50.97 (so a little out of round.

Bottom mount North-South measurement 50.99 and East West measurement is 50.95

Bearing OD of taper Bearing race 50.93mm.

By test fitting the outer race to the bearing mount it also apparent that the bearing mount has been splayed at the mouth - and the measurements I have taken are about mid way down - so right at the base of the bearing mount they are probably very close to right if not right - however the splayed mount seems to be the issue I want to address.

So the idea to press a collar onto the outside of the steering head - would seem to have merit - the question is how much spring is likely to exist?
I squeeze it in, it springs back to basically where it has been stretched to.

Secondly what is the impact of heat? Then it is a case of how much heat?

Thanks guys for listening and providing a lot of much appreciated advice.


Mal
 
sand the edges, put the middle ring/race in the freezer. heat the out edges, gease it then push and tap it in. done quite a few if them all balls conversions myself. plus make shure top and bottoms are correct. some times I,ve had to do a little more sanding on the inside than I, would like. just a sore thumb. but that's how mine have looked also. seems not rite but persuation will work.
 
Ryan, my problem is the bearing is loose in the race, I need the bore where the bearing fits to be smaller. David could you elaborate on heat shrinking the part (I assume you mean the steering head) - what temp would you heat the steering head too? Also given it has taken 50 years for the steering head to yawn - will it be more prone to stretching or will it take another 50 years to reoffend? If you see my grey hair (what I have left) you might appreciate I don't need to fix it for eternity - I just like the idea when the next person works on this machine will see the work I have done as elegant and competent (and while I hope that will be a long time down the track - I hope it remains worth maintaining).

Cheers


Mal
 
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