Fork crown repair
#1
Thread Starter
Senior Member


Joined: Jan 2008
Posts: 2,421
Likes: 22
From: Aurora, IL
Bikes: '73 Raleigh RRA, 1986 Trek 500 commuter
Fork crown repair
Due to a machine shop screw up (back in the '70s), my '73 Raleigh RRA fork has a crown race portion which was cut too small for an ISO Campy race (26.4mm). The fork crown measures ~25.96mm (according to my digital calipers). I either need to find a shop which can knurl this, or braze up the crown race portion and remachine it correctly.
Anyone on this board do this, or does anyone know of a shop in Chicago or burbs that can do either of these?
re: the original screw up; I had the fork replaced by the LBS because of an alignment issue with the original. The replacement must have been JIS size, as the Campy race would not fit on. The LBS was relatively new and didn't have a crown race cutter (NE Iowa).
Anyone on this board do this, or does anyone know of a shop in Chicago or burbs that can do either of these?
re: the original screw up; I had the fork replaced by the LBS because of an alignment issue with the original. The replacement must have been JIS size, as the Campy race would not fit on. The LBS was relatively new and didn't have a crown race cutter (NE Iowa).
#2
Before you try to braze or knurl the fork crown race oversize, you might try finding some sheet-metal that is 0.2mm thick, use it to make a shim between the fork steertube race and the headset race.
#3
Senior Member


Joined: Feb 2012
Posts: 19,353
Likes: 5,471
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
I'd probably lay some brass then remachine. Depends on the filler used for the crown/steerer. Andy.
#4
Randomhead
Joined: Aug 2008
Posts: 25,930
Likes: 4,825
From: Happy Valley, Pennsylvania
if knurling on a lathe would work, it would save the paint job if it is still good. Dunno if there is anyone in that area with a lathe, maybe check with Clockwork in Minneapolis ?
#5
Thread Starter
Senior Member


Joined: Jan 2008
Posts: 2,421
Likes: 22
From: Aurora, IL
Bikes: '73 Raleigh RRA, 1986 Trek 500 commuter
I checked with Chris Kvale in the twin cities and he will do it for a reasonable price (rebuild with silver and remachine). I've used shims for 35+ years, but I can only get those so tight, and figured it was time to fix it once and for all. Thanks for the suggestions.
EDIT: BTW, it was interesting to check with a few shops I know of down here. One, that has been in business for quite some time, had no idea what I was talking about
I also sent an email to RRB Cycles, as Ron at least used to build custom frames, but no reply yet. I'm not originally from here, so other than Licktons, have never been to any of the bigger or old school Chicago shops and don't know much about them.
EDIT: BTW, it was interesting to check with a few shops I know of down here. One, that has been in business for quite some time, had no idea what I was talking about
I also sent an email to RRB Cycles, as Ron at least used to build custom frames, but no reply yet. I'm not originally from here, so other than Licktons, have never been to any of the bigger or old school Chicago shops and don't know much about them.
Last edited by Pars; 02-11-13 at 06:30 PM.
#6
Senior Member


Joined: Feb 2012
Posts: 19,353
Likes: 5,471
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
You might check with Owen Lloyd <olloyd1@gmail.com> South side of Chitown doing a collective frame shop thing and owns a shop. Andy.
#7
Senior Member

Joined: Dec 2006
Posts: 1,221
Likes: 23
From: Toronto/Montréal
Bikes: Eight homemade, three very dusty
+1 on knurling. With the right tool (not any knurler would work) it's a quick job on a lathe, with no effects on the paint. JA Stein has a nice tool exactly for that, but I doubt many shops have it. I've also tried shimming, it works but it's a pain.
#8
Senior Member
Joined: Sep 2006
Posts: 201
Likes: 8
From: Bozeman MT
Bikes: Kirk
I'd shy away from trying to shim it. That is a VERY thin shim and will tend to crumple up below the race as it's pressed down. This very well could make the race fit tightly on the crown race seat but not sit squarely down onto the crown. It's a tough row to hoe.
The Stein tool was designed for just this and works just as it should.
Good luck.
dave
#9
For those not familar with the knurling tool it is $185 from one vendor, here's the link: https://www.universalcycles.com/search.php?q=stein+tool
and instructions: https://www.jastein.com/PDF/Stein%20K...nstruction.pdf
and instructions: https://www.jastein.com/PDF/Stein%20K...nstruction.pdf
#10
Randomhead
Joined: Aug 2008
Posts: 25,930
Likes: 4,825
From: Happy Valley, Pennsylvania
I guess I'll get a straight knurling wheel for my lathe. I suspect the crosshatched knurls would work just as well and Stein just went with straight because it's better for bench use, but why mess with success
#11
Thread Starter
Senior Member


Joined: Jan 2008
Posts: 2,421
Likes: 22
From: Aurora, IL
Bikes: '73 Raleigh RRA, 1986 Trek 500 commuter
Already sent off to Chris Kvale to be built up and remachined. If I could have found someone who could do the knurling I would have probably gone that route.
I would think crosshatched knurls would work better than straight (as the Stein tool does), but I might be missing something...
I would think crosshatched knurls would work better than straight (as the Stein tool does), but I might be missing something...
#13
Member
Joined: Apr 2009
Posts: 34
Likes: 1
if knurling on a lathe would work, it would save the paint job if it is still good. Dunno if there is anyone in that area with a lathe, maybe check with Clockwork in Minneapolis ?





