Steerer tube Replace or Repair? A Summary of Good Advice for Vintage Bike
03-20-24, 10:57 AM
#1
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Steerer tube Replace or Repair? A Summary of Good Advice for Vintage Bike
Steerer tube Replace or Repair? A Summary of Good Advice for Vintage Bike
“This must have been discussed here, but I haven't found it. Show me the way. Thanks, Steve”
This is a compilation of worthy advice I received from our members. Many agreed that the search capability of this site is limited. I hope this helps light up this little corner. Thanks to all of them. To save time and provide clarity, I have not acknowledged them individually
You are right, I was not clear enough. I have a "'44 vintage Rollfast ladies ballooner, which has a steerer tube that has been blown out. I wish to keep the original fork and replace it preferably, or repair the steerer tube. Despite my shabby articulation, our members understood and I have gotten some wonderful advice about repairing the tube, Thank you all for those responses. So far not much about removal. I imagine removal to be a less complicated process, and structurally more sound, but I'm here because i really don't know diddley.
Steve
I can't tell you about replacing it entirely. That might be more for a question in theFramebuilderssub-forum. I don't think many do that as a normal thing.
But since you are likely talking about a steel steerer tube, then cut it off at least a inch or so below where ever a quill stem might get too. And far enough away from the fork crown that the heat of brazing doesn't bother it.
Then braze on another piece of steerer tube of the same ID and OD with a internal union that is at least a half inch into each section of the joined tubes. Then dress up the outside with a file or something to bring the brazed joint back to the OD spec.
I wondered why a heating the original brazed joint and pulling the damaged tube out wouldn't be easier and the subsequent fix stronger.
My original search on this was disappointing, but I'm still learning how to navigate here.
Thanks for any ideas, Steve
If you get everything properly clean and close fitting you can use silver solder instead of bronze, significantly lower melting point so no risk of the steerer moving in the crown, and within the ability of a propane torch rather than needing oxy-fuel. I'd go with 7/8" insertion on each side i.e. the width of the inserted tube. Just be sure the solder flows fully, so you can see it all around the other end of the joint.
Not sure what the question is, so I'll guess and answer accordingly.
Assuming you're looking for a new fork for an old frame, odds greatly favor it being a standard (USA) 1" steerer. These are very similar, but different to modern 1" steerers, with a slightly smaller ID, different thread pitch, and different headset standards.
You may search for a vintage USA standard 26" middleweight fork, or use a modern fork, but having to replace the stem and headset.
Can you post a picture of the steerer/crown? I personally feel more comfortable replacing the entire steerer. But given the bike, I'm wondering if it's a standard steerer.
Do you know the stem diameter? Lots of older American bikes have an undersized stem, 0.833" instead of the more standard .875" (7/8")
Assuming you want a proper restoration, you might want to source the thicker-walled steerer that fits your undersized stem.
Both the "splice" method and the total-replacement method have been done plenty of times and can be safe and reliable if done well. Don't give it to someone who's never done one, there are enough experienced folks out there.
Personally I would not "sweat" (melt) the steerer out, too many unknowns. Like if they pinned it or tack-welded it and you don't know that, you can keep heating and heating until the crown is ruined and the steerer still hasn't budged. Safer to bore the crown to diamater on a mill or a lathe. Advantages: done cold so no more heat damage to the crown, and it doesn't care if the original was pinned or spot-welded. Disadvantage is it takes longer, mostly in the setup. A dedicated fixture is best, but building one will normally cost as much as buying a new fork. Maybe your repair guy has one already or wants to have this kind of fixture for future repairs, so you won't have to pay the full cost of making it. I have "planned" (dreamed of) to make one for something like 40 years now and haven't got around to it, just waiting for a fork that I care enough about to make it worth my time. I'm not offering to do it; I won't work on someone else's fork without product liability insurance. Maybe someday.
Mark, have you ever seen a picture of someone's steerer boring setup on a lathe? I suppose it's a lot like the fixtures people make to miter unicrown fork blades. I'll have to think about it.
I want to replace a steerer where I munged the threads at a bad place, right under where the threaded headset cup would go. Seems like it could be an annoyance for the life of the fork if I don't get rid of it. Or maybe I could fill it in with brass and thread it again.
No haven't seen one, that I can recall, but yeah about the same as for unicrown mitering. The same fixture could be used for both. Hold the dropouts, and the blades up near the crown. Bolt it to the cross slide somehow that lets you ensure it's parallel to the spindle, maybe with a center hole where you can stick a center mounted on the tailstock.
It'll need a height adjustment at the dropout end for the rake, and one at the crown end, though maybe just shimmimg there. Not much range of height adjustment needed since blades don't vary in size all that much. I figger I'd make it from 80/20, since you can bolt it together from off-the-shelf parts in minutes, no need to mill T-slots.
Filling with brass (or nickel-silver if you're concerned about strength) and re-cutting threads seems like a ton less work, and almost certainly good enough to last "forever". I'd try that for sure, because if it doesn't work, you can still replace the steerer.
“This must have been discussed here, but I haven't found it. Show me the way. Thanks, Steve”
This is a compilation of worthy advice I received from our members. Many agreed that the search capability of this site is limited. I hope this helps light up this little corner. Thanks to all of them. To save time and provide clarity, I have not acknowledged them individually
You are right, I was not clear enough. I have a "'44 vintage Rollfast ladies ballooner, which has a steerer tube that has been blown out. I wish to keep the original fork and replace it preferably, or repair the steerer tube. Despite my shabby articulation, our members understood and I have gotten some wonderful advice about repairing the tube, Thank you all for those responses. So far not much about removal. I imagine removal to be a less complicated process, and structurally more sound, but I'm here because i really don't know diddley.
Steve
I can't tell you about replacing it entirely. That might be more for a question in theFramebuilderssub-forum. I don't think many do that as a normal thing.
But since you are likely talking about a steel steerer tube, then cut it off at least a inch or so below where ever a quill stem might get too. And far enough away from the fork crown that the heat of brazing doesn't bother it.
Then braze on another piece of steerer tube of the same ID and OD with a internal union that is at least a half inch into each section of the joined tubes. Then dress up the outside with a file or something to bring the brazed joint back to the OD spec.
I wondered why a heating the original brazed joint and pulling the damaged tube out wouldn't be easier and the subsequent fix stronger.
My original search on this was disappointing, but I'm still learning how to navigate here.
Thanks for any ideas, Steve
If you get everything properly clean and close fitting you can use silver solder instead of bronze, significantly lower melting point so no risk of the steerer moving in the crown, and within the ability of a propane torch rather than needing oxy-fuel. I'd go with 7/8" insertion on each side i.e. the width of the inserted tube. Just be sure the solder flows fully, so you can see it all around the other end of the joint.
Not sure what the question is, so I'll guess and answer accordingly.
Assuming you're looking for a new fork for an old frame, odds greatly favor it being a standard (USA) 1" steerer. These are very similar, but different to modern 1" steerers, with a slightly smaller ID, different thread pitch, and different headset standards.
You may search for a vintage USA standard 26" middleweight fork, or use a modern fork, but having to replace the stem and headset.
Can you post a picture of the steerer/crown? I personally feel more comfortable replacing the entire steerer. But given the bike, I'm wondering if it's a standard steerer.
Do you know the stem diameter? Lots of older American bikes have an undersized stem, 0.833" instead of the more standard .875" (7/8")
Assuming you want a proper restoration, you might want to source the thicker-walled steerer that fits your undersized stem.
Both the "splice" method and the total-replacement method have been done plenty of times and can be safe and reliable if done well. Don't give it to someone who's never done one, there are enough experienced folks out there.
Personally I would not "sweat" (melt) the steerer out, too many unknowns. Like if they pinned it or tack-welded it and you don't know that, you can keep heating and heating until the crown is ruined and the steerer still hasn't budged. Safer to bore the crown to diamater on a mill or a lathe. Advantages: done cold so no more heat damage to the crown, and it doesn't care if the original was pinned or spot-welded. Disadvantage is it takes longer, mostly in the setup. A dedicated fixture is best, but building one will normally cost as much as buying a new fork. Maybe your repair guy has one already or wants to have this kind of fixture for future repairs, so you won't have to pay the full cost of making it. I have "planned" (dreamed of) to make one for something like 40 years now and haven't got around to it, just waiting for a fork that I care enough about to make it worth my time. I'm not offering to do it; I won't work on someone else's fork without product liability insurance. Maybe someday.
Mark, have you ever seen a picture of someone's steerer boring setup on a lathe? I suppose it's a lot like the fixtures people make to miter unicrown fork blades. I'll have to think about it.
I want to replace a steerer where I munged the threads at a bad place, right under where the threaded headset cup would go. Seems like it could be an annoyance for the life of the fork if I don't get rid of it. Or maybe I could fill it in with brass and thread it again.
No haven't seen one, that I can recall, but yeah about the same as for unicrown mitering. The same fixture could be used for both. Hold the dropouts, and the blades up near the crown. Bolt it to the cross slide somehow that lets you ensure it's parallel to the spindle, maybe with a center hole where you can stick a center mounted on the tailstock.
It'll need a height adjustment at the dropout end for the rake, and one at the crown end, though maybe just shimmimg there. Not much range of height adjustment needed since blades don't vary in size all that much. I figger I'd make it from 80/20, since you can bolt it together from off-the-shelf parts in minutes, no need to mill T-slots.
Filling with brass (or nickel-silver if you're concerned about strength) and re-cutting threads seems like a ton less work, and almost certainly good enough to last "forever". I'd try that for sure, because if it doesn't work, you can still replace the steerer.
03-20-24, 06:14 PM
#2
Junior Member
I had my 1 inch steel fork ( "531 Pro" ) steerer repaired by a highly experienced frame builder. I wouldn't have used anybody for this critical repair but I am 100 % convinced the repair he did is as strong as the original set-up. I have some welding background so was able to confirm procedure and inspect outcome.
He did it the way described above ( cut and internally sleeve ) except he full penetration tig welded it. I am guessing he cooled the crown area perhaps with wet rags or similar. Not a mark of discolouration on the chrome ( all chrome fork ). He also ground down the proud weld areas and checked the runout of the steerer, I think in a lathe.
I think repair is easier than replacement if you can find a highly competent welder ( or brazer ? ). But not something an amateur should even think about as requires very high skills.
I think pulling out an old steerer from a fork crown and rebrazing a new one in, probably involves more unknowns ( cleaning up old braze while maintaining original parts clearances, and perhaps alignment issues with the steerer and the fork, may need a jig ) compared to repair.
Repair seems to involve well-known and common practices, compared to more obscure and esoteric practices involved in replacement.
My fork repairer totally saved an in practice unobtainable 40 year old original fork and replacing it with a new high-quality "generic" fork ( not easy to find anyway ) would have spoiled the bike's originality.
He did it the way described above ( cut and internally sleeve ) except he full penetration tig welded it. I am guessing he cooled the crown area perhaps with wet rags or similar. Not a mark of discolouration on the chrome ( all chrome fork ). He also ground down the proud weld areas and checked the runout of the steerer, I think in a lathe.
I think repair is easier than replacement if you can find a highly competent welder ( or brazer ? ). But not something an amateur should even think about as requires very high skills.
I think pulling out an old steerer from a fork crown and rebrazing a new one in, probably involves more unknowns ( cleaning up old braze while maintaining original parts clearances, and perhaps alignment issues with the steerer and the fork, may need a jig ) compared to repair.
Repair seems to involve well-known and common practices, compared to more obscure and esoteric practices involved in replacement.
My fork repairer totally saved an in practice unobtainable 40 year old original fork and replacing it with a new high-quality "generic" fork ( not easy to find anyway ) would have spoiled the bike's originality.
03-21-24, 08:19 AM
#3
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"Repair seems to involve well-known and common practices, compared to more obscure and esoteric practices involved in replacement." redshift1
Only obscure/esoteric to those who haven't done this stuff. In my world replacement is easier to do better, although with more heat issues to the crown and upper blades' paint/chrome. Andy
Only obscure/esoteric to those who haven't done this stuff. In my world replacement is easier to do better, although with more heat issues to the crown and upper blades' paint/chrome. Andy
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03-25-24, 07:40 PM
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I had my 1 inch steel fork ( "531 Pro" ) steerer repaired by a highly experienced frame builder. I wouldn't have used anybody for this critical repair but I am 100 % convinced the repair he did is as strong as the original set-up. I have some welding background so was able to confirm procedure and inspect outcome.
He did it the way described above ( cut and internally sleeve ) except he full penetration tig welded it.
He did it the way described above ( cut and internally sleeve ) except he full penetration tig welded it.
03-26-24, 02:53 AM
#5
Junior Member
Yes this is a specialist job outside my welding experience. I know about pre-heating and post-cooling of crack prone steels but I still wouldn't do this job at home, in part because as you infer, 531 is more suited to being brazed rather than welded. However I remain 100 % convinced as to the quality of the repair entirely because of the reputation of the frame builder who did the job.
