stripped threaded fork
#1
Thread Starter
46 bikes and counting...
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Bikes: 1992 Trek multitrack 700 sourgrape with red decals, 1992 Trek multtrack 700 (with 1" threadless conversion), 2009 jamis Aurora Elite, 2007 Jamis Cross Country 2.0, 1981 Trek 613, 1980's Fuji "Redlof" folding bike, Iron Horse AT-70 with 48cc motor....
stripped threaded fork
Ok I have a common problem here, the threads on the fork have been stripped so that the headset can't bite and rocks. So heres my question: Short of replacing the fork, which has huge sentimental value (don't ask), is there any crazy way of making it work? Time, effort and money are no object (again huge sentimental value). I've been thinking of filling down the rest of the threads, using a shim and a quill stem adapter. But that doesn't allow me to keep the correct pressure on the headset.
Yes I know this is kinda stupid, but help me out here. Thanks.
Yes I know this is kinda stupid, but help me out here. Thanks.
#2
Senior Member
Joined: Aug 2005
Posts: 33,657
Likes: 1,119
From: Pittsburgh, PA
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
I presume the original threads are damaged to the point where just "chasing" them with a threading die won't be enough.
I have heard of having a frame maker melt brazing brass into the damaged threads and then recut the threads using the proper threading die.
I have heard of having a frame maker melt brazing brass into the damaged threads and then recut the threads using the proper threading die.
#3
Senior Member

Joined: May 2004
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From: Wilmington, DE
Bikes: 2016 Hong Fu FM-079-F, 1984 Trek 660, 2005 Iron Horse Warrior Expert, 2009 Pedal Force CX1, 2016 Islabikes Beinn 20 (son's)
A shorter stack headset is another option if your current headset stack height allows for it.
#5
cab horn

Joined: Jun 2004
Posts: 28,353
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From: Toronto
Bikes: 1987 Bianchi Campione
Ok I have a common problem here, the threads on the fork have been stripped so that the headset can't bite and rocks. So heres my question: Short of replacing the fork, which has huge sentimental value (don't ask), is there any crazy way of making it work? Time, effort and money are no object (again huge sentimental value). I've been thinking of filling down the rest of the threads, using a shim and a quill stem adapter. But that doesn't allow me to keep the correct pressure on the headset.
Yes I know this is kinda stupid, but help me out here. Thanks.
Yes I know this is kinda stupid, but help me out here. Thanks.
#6
Bump since I think the same thing happened to me, see attached.
I have no idea how this happened. It's an old used fork with a basic, bought-new headset. I've commuted daily on the bike for over a year since I replaced the headset. Suddenly it started loosening up while I ride. Tightening the top nut just hits the stop, even after I added two spacers to the stack.
I'm willing to replace the fork, but I think I might have a hard time finding a shop that stocks used parts around here. Would this eventually stop loosening if I added more spacers? Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
I have no idea how this happened. It's an old used fork with a basic, bought-new headset. I've commuted daily on the bike for over a year since I replaced the headset. Suddenly it started loosening up while I ride. Tightening the top nut just hits the stop, even after I added two spacers to the stack.
I'm willing to replace the fork, but I think I might have a hard time finding a shop that stocks used parts around here. Would this eventually stop loosening if I added more spacers? Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
#7
Senior Member

Joined: Mar 2003
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From: Beaufort, South Carolina, USA and surrounding islands.
Bikes: Cannondale R500, Motobecane Messenger
1" threaded forks can still be found. Nashbar even has a 1" threaded carbon fiber 700c fork.
I hope that is just a paint crack on the weld at the top tube/head tube joint on Capt. Cool's frame.
I hope that is just a paint crack on the weld at the top tube/head tube joint on Capt. Cool's frame.
#8
Senior Member
Joined: Dec 2009
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From: Melbourne, Oz
Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231
Suddenly it started loosening up while I ride. Tightening the top nut just hits the stop, even after I added two spacers to the stack.
...
Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
...
Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
Yeah, that's a bit disconcerting... bears investigation.
#9
I hope that is just a paint crack on the weld at the top tube/head tube joint on Capt. Cool's frame.
It's an old gaspipe frame, heavy and solid, but I should look it over again. Thanks.
I should be able to tighten the cup by tightening a nut above it. And if I "lock" two nuts together above the cup, the cup won't go anywhere. Right?
#10
Having a frame-builder with brazing-rod would be idea - but also more expensive than replacing same. Certainly in the long run. If you have a classic bicycle where substituted forks would harm it's value - go ahead with the frame-builder. And hang it on your wall.
1 inch forks are available and a mitre-block is pretty cheap - or have your LBS assist.
Tally Ho!
1 inch forks are available and a mitre-block is pretty cheap - or have your LBS assist.
Tally Ho!
#11
Old fart



Joined: Nov 2004
Posts: 26,327
Likes: 5,238
From: Appleton WI
Bikes: Several, mostly not name brands.
Bump since I think the same thing happened to me, see attached.
I have no idea how this happened. It's an old used fork with a basic, bought-new headset. I've commuted daily on the bike for over a year since I replaced the headset. Suddenly it started loosening up while I ride. Tightening the top nut just hits the stop, even after I added two spacers to the stack.
I'm willing to replace the fork, but I think I might have a hard time finding a shop that stocks used parts around here. Would this eventually stop loosening if I added more spacers? Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
I have no idea how this happened. It's an old used fork with a basic, bought-new headset. I've commuted daily on the bike for over a year since I replaced the headset. Suddenly it started loosening up while I ride. Tightening the top nut just hits the stop, even after I added two spacers to the stack.
I'm willing to replace the fork, but I think I might have a hard time finding a shop that stocks used parts around here. Would this eventually stop loosening if I added more spacers? Could I add another threaded nut / old top race to the stack, to lock against the top nut like the current top race is supposed to?
#12
I will look for a replacement fork. But I still don't see how this follows. If I could tighten down a nut above the spacers to set the cup, and then another nut on top of that to lock it, why wouldn't that hold?
#13
Most likely the steering tube is pressed in, and so it can also be pressed out and subsequently replaced by and machine shop or, as suggested, frame builder.
Sometimes improvising a little bit is the most cost effective way to proceed. The purpose of the top nut is to preload the bearings of the headset, providing the radial and axial stability the application requires. If you can find an appropriately sized spacer and engage the thread where it's not stripped, go for it
. You might even put a dab of loctite on those threads to keep it from backing out ever.
Sometimes improvising a little bit is the most cost effective way to proceed. The purpose of the top nut is to preload the bearings of the headset, providing the radial and axial stability the application requires. If you can find an appropriately sized spacer and engage the thread where it's not stripped, go for it
. You might even put a dab of loctite on those threads to keep it from backing out ever.
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#14
Here is an interest trick that may work from https://ratrodbikes.com/forum/viewtop...p=13190#p13190 (scroll down for more info. Alot of the images are missing but you should get the idea)
grind of the top beveled/cap part of the nut so it will look/act like any ordinary nut. You would be able to screw it down the fork tube as far as you want without it bottoming out.
Then cut the nut in two so you have a right and left half.
Wrap the 2 halves around the fork tube below the bad spot thus putting the nut back together. Vice grip the 2 halves to hold them together.
Now unscrew up and over the bad spot.
grind of the top beveled/cap part of the nut so it will look/act like any ordinary nut. You would be able to screw it down the fork tube as far as you want without it bottoming out.
Then cut the nut in two so you have a right and left half.
Wrap the 2 halves around the fork tube below the bad spot thus putting the nut back together. Vice grip the 2 halves to hold them together.
Now unscrew up and over the bad spot.
#15
Old fart



Joined: Nov 2004
Posts: 26,327
Likes: 5,238
From: Appleton WI
Bikes: Several, mostly not name brands.
You really do need to either fix the threads or replace the fork.
#16
Senior Member

Joined: Sep 2009
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Bikes: Masi, Giant TCR, Eisentraut (retired), Jamis Aurora Elite, Zullo, Cannondale, 84 & 93 Stumpjumpers, Waterford, Tern D8, Bianchi, Gunner Roadie, Serotta, Serotta Duette, was gifted a Diamond Back
Without intact threads, there's nothing to hold the cup in a stable position. If you adjust it so the bearings rotate smoothly, the cup will wobble on the steer tube (try it if you don't believe me -- it may work for a short while in the work stand, but not on the road in the long term). If you adjust it so the cup doesn't wobble, the the bearing will not turn smoothly.
You really do need to either fix the threads or replace the fork.
You really do need to either fix the threads or replace the fork.
I think that the op is thinking is to press the race cap with spacers and similar to a threadless headset. This will not work well because of the existing damage to the threaded portion of the steerer. there are no longer the close tolerances neccessary to prevent the race cap from wobbling and will eventually cause more damage to the steerer and the races and bearings. This is something that should be fixed the correct way.
#17
Without intact threads, there's nothing to hold the cup in a stable position. If you adjust it so the bearings rotate smoothly, the cup will wobble on the steer tube (try it if you don't believe me -- it may work for a short while in the work stand, but not on the road in the long term). If you adjust it so the cup doesn't wobble, the the bearing will not turn smoothly.
You really do need to either fix the threads or replace the fork.
You really do need to either fix the threads or replace the fork.
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