It's never easy (graphic content)
#1
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 912
Likes: 9
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:

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

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

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...
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:

The steerer tube was attached to the fork crown not by brazing, but by the brake center bolt
It appears there is hardly any brass in the interface:
On the plus side, the BB area looks clean, even if the mitering is not to the highest standards. The tubes are pinned:

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...
#2
Spin Forest! Spin!
Joined: Sep 2007
Posts: 5,956
Likes: 18
From: Arrid Zone-a
Bikes: I used to have many. And I Will again.
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.
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.
#6
www.theheadbadge.com



Joined: Sep 2005
Posts: 29,001
Likes: 5,492
From: Southern Florida
Bikes: https://www.theheadbadge.com
#9
Membership Not Required
Joined: Jan 2005
Posts: 16,853
Likes: 18
From: On the road-USA
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Might prove expensive...unless we can get it wholesale 
Aaron

Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(
ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.
"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"_Nicodemus
"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"_krazygluon
#11
www.theheadbadge.com



Joined: Sep 2005
Posts: 29,001
Likes: 5,492
From: Southern Florida
Bikes: https://www.theheadbadge.com
#12
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.
The steerer tube was attached to the fork crown not by brazing, but by the brake center bolt
It appears there is hardly any brass in the interface:

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...
The steerer tube was attached to the fork crown not by brazing, but by the brake center bolt
It appears there is hardly any brass in the interface:
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...
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.
__________________
Jeff Wills
Comcast nuked my web page. It will return soon..
Jeff Wills
Comcast nuked my web page. It will return soon..
#15
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 912
Likes: 9
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?
#19
Senior Member


Joined: Jun 2006
Posts: 21,802
Likes: 3,703
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.
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.
#20
Old fart



Joined: Nov 2004
Posts: 26,323
Likes: 5,232
From: Appleton WI
Bikes: Several, mostly not name brands.
Yes, definitely a defective joint. The brass should have fully penetrated the joint, and if it had it never would have failed.
#21
Thread Starter
Senior Member
Joined: Apr 2005
Posts: 912
Likes: 9
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.
#22
Half way there
Joined: May 2011
Posts: 1,109
Likes: 1
From: Durham, NC
Bikes: 69 Hercules, 73 Raleigh Sports, 74 Raliegh Competition, 78 Nishiki Professional, 79 Nishiki International, 83 Colnago Super, 83 Viner Junior
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
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







