It's never easy (graphic content)
 

So I started disassembling the '69 Raleigh Pro I talked about in this thread. It started easy enough, but I noted that the stem nut was stuck. I sprayed some PB Blaster, then removed other components. The front Mafac centerpull was hard to removed, I had to thread the bolt rather than just push it out.

Then I noticed that the headset suddenly got looser. It was tight and had a slightly indexed feel, but now felt loose. I was hoping it wasn't what I feared, but it was:

http://i180.photobucket.com/albums/x...f/P1040652.jpg

The steerer tube was attached to the fork crown not by brazing, but by the brake center bolt :eek: It appears there is hardly any brass in the interface:

http://i180.photobucket.com/albums/x...f/P1040654.jpg

On the plus side, the BB area looks clean, even if the mitering is not to the highest standards. The tubes are pinned:

http://i180.photobucket.com/albums/x...f/P1040651.jpg

So, how easy is this repair? I assume the crown race area will have to be built up from brass, is this OK? Time to talk to a framebuilder...

Wow! I feel your disappointment. From the photos, where IS the crown race?!? Looks like it's completely worn away. Could someone have simply dropped the bearing cage onto the fork without the headset race installed?

Perhaps that's why the fork failed?
I don't think you can build it back up with brass. Maybe a machined steel ring could be fitted and brazed on.

JB Weld it.

Hell, let's just see if we can make a whole bike out of JB Weld.

We have cardboard bicycles, why not JB?

http://www.treehugger.com/student-de...rd-bicycle.jpg

I've seen a few Raleighs where the raceway has been milled/cut that far down until it looks like that. Don't know why.

-Kurt

I'd think it could be rebrazed if they could get it clean enough.

The crown race (part of the headset) just fell of when I pulled off the steerer. It looks to me like not enough brass penetrated the junction, so the milled area around the crown race was overstressed.

Might prove expensive...unless we can get it wholesale :D

Aaron :)

Silver solder???

Silver, brass - any of these repairs will burn the original paint, but they're his only option.

...short of threading the brake back in there :eek:

-Kurt

Sweet plastic Elvis, you got lucky. I can't imagine what would have happened if the brake bolt wasn't holding it together.

Yes, talk to a framebuilder. It's going to be an iffy proposition, filling that worn gap with brass without overheating the whole shebang and still having it come out straight.

It should be fairly easy to fix. No problem building up the race seat with brass and re-milling it to the proper diameter.

Please.

That's a "fiber composite" (or maybe "fiber compost") frame.

Would you say this is a defective joint? I have never looked at a fork crown failure before, but I would have expected more brass visible. Or is it hard to say without a magnifier?

That Mafac Brake bolt must be grade 8.

puts the death fork on my viscount to shame, at least that has a couple pins in it. :lol:

I have an acetylene torch...no skills with it beyond the crude though.

Monday morning brazing, the flux held it together for a time. Too many pints on Sunday evening.

Not the first time I have seen this. I would probably opt for a new steerer, the outside diameter will not be worn, it can be left long then filed back after, the extra length makes the application of heat easier and the flow too. The paint is going to be toast of course.

Yes, definitely a defective joint. The brass should have fully penetrated the joint, and if it had it never would have failed.

The paint is in poor shape overall, but I like the patina. I would like to ride it a bit to see I want to spring for a real paint job. I will probably spray it with appliance enamel temporarily, white should be a good enough match for the frame color.

Definitely a poor brazing job - with the easy ability to gauge brass penetration on this joint, it's hard to imagine how this happened. Built on Monday maybe?

How's the fit of the steerer tube to the fork crown? It certainly looks a bit gauled. If the fit is still good, it should be easily rebrazed. If it is too loose, rebrazing may introduce an alignment problem.

Find either a good framebuilder or a replacement fork (which may be hard to find)

Good luck

-Gary

I wouldn't think this would be a difficult repair. That's just me, though.

i don't even get it..

What? A social disease?