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-   -   Campy BB fixed cup damaged threads (https://www.bikeforums.net/classic-vintage/1254160-campy-bb-fixed-cup-damaged-threads.html)

merziac 07-06-22 01:49 PM


Originally Posted by oneclick (Post 22565041)
Go backwards - if a right-threaded cup, place it in the shell and turn anti-clockwise with light pressure. When the cup gets to a point it will drop inwards one thread and that's when you know you have the start.

For damaged threads there may be more than one point where the cup drops. Check the cup visually as most often the original threads will still be there, and hopefully they are still deeper and better formed than whatever damage there is. Go around several times and decide which point has the best-feeling drop - size, and at the moment after the drop look at the alignment. Use that.


Yeah, that's the standard working theory for this, not always that straight forward and not for the inexperienced.

Not always, that's where many make their mistake, if the starting threads are only half good after a rework, they can get you in more trouble so caution wins the day.

If you screw this up at the drag strip, you don't make the next round, I never missed a round in 25 years.

Never had to pull a motor or transmission out or apart either for this in 35 years, 25 professionally. ;)

JackJohn 07-06-22 03:33 PM


Originally Posted by merziac (Post 22564703)
Thats the best kind to use and they have single bade ones kind of like a knife blade, as we know a hacksaw isn't tapered like a file. Well my hacking inclination is pretty strong having been a mech/tech all my life, drag racing mc's for 25 years and plenty else, many here don't agree with some of my methods but if you proceed with an abundance of caution and patience, you can succeed with some pretty unorthodox workarounds.

In general, any "loctite" other than red is an oxymoron, its not loctite if it doesn't hold semi permanent.

In this situation it seems likely to come loose more easily when already prone to do so.

Never had anything put up much of a fight, even with red, I would get this completely clean and dry and lock it down good. these are where I use my removal method setup to tighten these when I think they won't stay tight and it always gets them apart afterwards too.

This has never failed to remove a cup without any damage to the tools, parts, frames, paint or flesh.

The oldschool Sugino wrench is the key but others work with this when you trap them in place so you can really lean on them, adding a pipe when necessary. ;)

Great, will follow your tips. I have a similar removal tool, but instead of a pipe I use a hammer :crash:

merziac 07-06-22 03:56 PM


Originally Posted by JackJohn (Post 22565861)
Great, will follow your tips. I have a similar removal tool, but instead of a pipe I use a hammer :crash:

Yeah but if you are going the wrong way or you slip/miss, it can get way uglier in a big hurry.

Hammers are for nails or problems that will result in destruction anyway.

And they can screw up the other tool.

JackJohn 07-06-22 04:11 PM


Originally Posted by oneclick (Post 22565041)
Go backwards - if a right-threaded cup, place it in the shell and turn anti-clockwise with light pressure. When the cup gets to a point it will drop inwards one thread and that's when you know you have the start.

For damaged threads there may be more than one point where the cup drops. Check the cup visually as most often the original threads will still be there, and hopefully they are still deeper and better formed than whatever damage there is. Go around several times and decide which point has the best-feeling drop - size, and at the moment after the drop look at the alignment. Use that.


Originally Posted by merziac (Post 22565696)
Yeah, that's the standard working theory for this, not always that straight forward and not for the inexperienced.

Not always, that's where many make their mistake, if the starting threads are only half good after a rework, they can get you in more trouble so caution wins the day.

If you screw this up at the drag strip, you don't make the next round, I never missed a round in 25 years.

Never had to pull a motor or transmission out or apart either for this in 35 years, 25 professionally. ;)

I think I see your point here, certainly you need some experience to get that kind of feeling and precision and to be able to detect anomalies in threads.
I had taste of this today on another campy bb, Italian thread. The lockring engaged in the adjustable cup and just using hands it was stuck as soon as all threads were in. I tried to inspect it having in mind what has been said here, but couldn’t find anything. Another identical lockring from another bb worked just fine, so the problem was not the cup. As I went on with a wrench and did a few back and forth, eventually I was able to tighten by hand up to halfway. However, when I tried the lockring on another adjustable cup, it engaged but stopped after the first thread. This is the kind of situations where I’m still not sure of what happens and what would be acceptable, and where experience matters.
All this to say that yes, you have to practice through different situations to learn. But also that this forum is an exceptional source of knowledge thanks to all of you !!! :thumb:

merziac 07-06-22 05:29 PM


Originally Posted by JackJohn (Post 22565925)
I think I see your point here, certainly you need some experience to get that kind of feeling and precision and to be able to detect anomalies in threads.
I had taste of this today on another campy bb, Italian thread. The lockring engaged in the adjustable cup and just using hands it was stuck as soon as all threads were in. I tried to inspect it having in mind what has been said here, but couldn’t find anything. Another identical lockring from another bb worked just fine, so the problem was not the cup. As I went on with a wrench and did a few back and forth, eventually I was able to tighten by hand up to halfway. However, when I tried the lockring on another adjustable cup, it engaged but stopped after the first thread. This is the kind of situations where I’m still not sure of what happens and what would be acceptable, and where experience matters.
All this to say that yes, you have to practice through different situations to learn. But also that this forum is an exceptional source of knowledge thanks to all of you !!! :thumb:

Yep, when ever I have a hangup, I clean it spotless, get out the strong reading glasses and a right angle pick. Starting from the inside I scribe the pick through the threads mm by mm in the unscrewing direction, sometimes the anomaly is so small you barely notice it with the pick but it works better after you scribe it. You can push some pretty bad gacks into a better state doing this, then the anti-seize and chaser can really refine it from there.

Never had one I didn't save, often it goes worse for the frustration and challenge of it.

It is a tedious process but can save the day when it goes well.

Biggest thing is to lean into it so you really get a feel for it. ;)

bulgie 07-06-22 08:59 PM


Originally Posted by merziac (Post 22565900)
Hammers are for nails <snip>

I try to keep hammers away from my nails, they grow back so slowly and I really miss them... so I try to miss them!

Road Fan 07-06-22 10:10 PM


Originally Posted by juvela (Post 22554568)
-----

you show the threads on the cup but what about those in the shell?

you could test fit another metric thread fixed cup as a diagnostic

if shell threads slightly damaged you can make a chasing tap by cutting slots into an old metric fixed cup with a bench grinder/die grinder/Dremel tool

https://www.bikeforums.net/attachmen...1&d=1637938312
such a chaser is not capable of making new threads but can reform damaged ones

-----

Another too that can help is a thread restoring file, from McMaster-Carr. It has a set of teeth you can run along the damaged threads. It won't restore steel which has already been lost, but it will help to cut the remnants of the old threads to that threading can happen between the cup and the BB inner surface. The strength will not be exactly what it was because the threads have lost some material, but it will often result in usable parts recovered from an absolute disaster.for a french 10 threads per centimeter thread, the too has a 0.100 edge.

Road Fan 07-06-22 10:19 PM


Originally Posted by JackJohn (Post 22554659)
Thanks guys! Yes, I can make a chaser if the bb shell is not too damaged, as said I tested another bb cup and worked fine, hence my puzzling, if the the shell was damaged that wouldn’t have worked.
In the end, my aim is to understand if I can still use that Campy bb cup or if the risk of damaging the frame shell is high, from my experiment above it’s not clear, your answers are clearer on that ;)
oneclick in point c) do you mean completely removing the damaged threads and have a flat surface instead? Will the cup have enough threads to hold tight?


I would suggest trying a thread restoring file before more drastic measures like cutting the existing cup into a thread chaser (a chaser is not a tap or die, it's more of a cleaner than a cutter.) or grinding threads. Mainly because my hand skills are better than my machine tool skills, and I'm 99.9% sure I can do a lot less damage with a hand tool than with a cutting machine or a serious cutting tool, and 100% sure I can make those threads rather clearer and straighter with the thread restoring file.

merziac 07-06-22 10:26 PM


Originally Posted by Road Fan (Post 22566325)
Another too that can help is a thread restoring file, from McMaster-Carr. It has a set of teeth you can run along the damaged threads. It won't restore steel which has already been lost, but it will help to cut the remnants of the old threads to that threading can happen between the cup and the BB inner surface. The strength will not be exactly what it was because the threads have lost some material, but it will often result in usable parts recovered from an absolute disaster.for a french 10 threads per centimeter thread, the too has a 0.100 edge.

:wtf:See post #19-24, we discussed this at length and yes they can save the day with patience and practice.

Road Fan 07-07-22 06:08 AM


Originally Posted by merziac (Post 22566348)
:wtf:See post #19-24, we discussed this at length and yes they can save the day with patience and practice.

Yes, thank you, mea culpa! The one I have is the same as the one in your picture.

I used it very extensively on wheel axles, hub cones, BB cups, and freewheel threadings when rebuilding my friend's two Witcombs. Used carefully, it's a great way to "subtract" the distorted metal which prevents threads from interleaving. When the damage was done the possibility of a full strength joint was reduced, but with the ability to join restored, a lot of bikes can be good enough.

merziac 07-07-22 01:25 PM


Originally Posted by Road Fan (Post 22566501)
Yes, thank you, mea culpa! The one I have is the same as the one in your picture.

I used it very extensively on wheel axles, hub cones, BB cups, and freewheel threadings when rebuilding my friend's two Witcombs. Used carefully, it's a great way to "subtract" the distorted metal which prevents threads from interleaving. When the damage was done the possibility of a full strength joint was reduced, but with the ability to join restored, a lot of bikes can be good enough.

Yep, no worries.

I like to use the scribeing method or chasers first, they can push the displaced material back in place and it will fill the the void closer to what it was and stay that way if we properly clean and tighten it as well as using some thread locker, red at least or SG. ;)

JackJohn 07-07-22 04:45 PM


Originally Posted by merziac (Post 22566033)
Yep, when ever I have a hangup, I clean it spotless, get out the strong reading glasses and a right angle pick. Starting from the inside I scribe the pick through the threads mm by mm in the unscrewing direction, sometimes the anomaly is so small you barely notice it with the pick but it works better after you scribe it. You can push some pretty bad gacks into a better state doing this, then the anti-seize and chaser can really refine it from there.


Originally Posted by Road Fan (Post 22566501)
I used it very extensively on wheel axles, hub cones, BB cups, and freewheel threadings when rebuilding my friend's two Witcombs. Used carefully, it's a great way to "subtract" the distorted metal which prevents threads from interleaving. When the damage was done the possibility of a full strength joint was reduced, but with the ability to join restored, a lot of bikes can be good enough.


Originally Posted by merziac (Post 22567134)
I like to use the scribeing method or chasers first, they can push the displaced material back in place and it will fill the the void closer to what it was and stay that way if we properly clean and tighten it as well as using some thread locker, red at least or SG. ;)

Thanks for these details guys! Next investments: a pick and a thread file! Can a 1mm (25.4tpi) file also be used on a 24 tpi (1.06mm) or the pitch must be exactly the same?

FYI on that Italian lockring mentioned above I still haven’t come to a conclusion: it eventually ended up tightening on its cup but doesn’t work anywhere else. Another lockring that tightens everywhere is now a bit looser on this cup. I wonder if a lockring can be harder than a cup at the point of damaging it…
ps: very practical the reading glasses, one of the benefits of aging;)

Road Fan 07-07-22 05:42 PM


Originally Posted by JackJohn (Post 22567352)
Thanks for these details guys! Next investments: a pick and a thread file! Can a 1mm (25.4tpi) file also be used on a 24 tpi (1.06mm) or the pitch must be exactly the same?

FYI on that Italian lockring mentioned above I still haven’t come to a conclusion: it eventually ended up tightening on its cup but doesn’t work anywhere else. Another lockring that tightens everywhere is now a bit looser on this cup. I wonder if a lockring can be harder than a cup at the point of damaging it…
ps: very practical the reading glasses, one of the benefits of aging;)

No, you have to have a file with the right pitch for each bolt. McMaster-Carr sold (may still sell) a set of two combination files, one with an assortment of metric sizes and one with an assortment of English sizes. What I did not find is 26 tpi, the obsolete Raleigh thread pitch.

merziac 07-07-22 10:30 PM


Originally Posted by JackJohn (Post 22567352)
Thanks for these details guys! Next investments: a pick and a thread file! Can a 1mm (25.4tpi) file also be used on a 24 tpi (1.06mm) or the pitch must be exactly the same?

FYI on that Italian lockring mentioned above I still haven’t come to a conclusion: it eventually ended up tightening on its cup but doesn’t work anywhere else. Another lockring that tightens everywhere is now a bit looser on this cup. I wonder if a lockring can be harder than a cup at the point of damaging it…
ps: very practical the reading glasses, one of the benefits of aging;)


Originally Posted by Road Fan (Post 22567393)
No, you have to have a file with the right pitch for each bolt. McMaster-Carr sold (may still sell) a set of two combination files, one with an assortment of metric sizes and one with an assortment of English sizes. What I did not find is 26 tpi, the obsolete Raleigh thread pitch.

Well, in a perfect world, maybe yes, maybe no, if its a bicycle only specific size and VAR didn't make it, then you may be SOL. :twitchy:

You may have to go with what you have or can find, I have several different multi thread files, 6 I think and still don't have the right pitch often and have to get as close as I can. Sometimes you have to blaze a trail and make the best of it.

At a certain point you have gather your chi and dive in, feel your way through and trust your judgement when it doesn't go wrong but try to be quick to recognize when it does and hopefully correct course before it goes too far south

The lockring above is a good example, if you can determine it works well enough to try it then do so with caution and diligence, keep an eye on it and see how it goes. In this case I would reinforce it well with loctite at least although I would go further, SG or even a tiny bit of JB.

If it holds together then all good, maybe only this one time but you have garnered judgement and experience that can mitigate some of this uncertainty next time.

There are usually only a few right ways, lots of wrong ways and a combination of those and more, my way.

I've made a pretty good living, won a heck of lot of races at the drag strip and solved many pita problems along the way.

oneclick 07-08-22 04:21 AM


Originally Posted by Road Fan (Post 22567393)
No, you have to have a file with the right pitch for each bolt. McMaster-Carr sold (may still sell) a set of two combination files, one with an assortment of metric sizes and one with an assortment of English sizes. What I did not find is 26 tpi, the obsolete Raleigh thread pitch.

Search for a Blue Point No 2 restore tool - there are a couple right now on that auction site..

JackJohn 07-08-22 02:40 PM


Originally Posted by Road Fan (Post 22567393)
No, you have to have a file with the right pitch for each bolt. McMaster-Carr sold (may still sell) a set of two combination files, one with an assortment of metric sizes and one with an assortment of English sizes. What I did not find is 26 tpi, the obsolete Raleigh thread pitch.

ok, I’ll start searching… :thumb:

JackJohn 07-08-22 02:44 PM


Originally Posted by merziac (Post 22567625)
Well, in a perfect world, maybe yes, maybe no, if its a bicycle only specific size and VAR didn't make it, then you may be SOL. :twitchy:

You may have to go with what you have or can find, I have several different multi thread files, 6 I think and still don't have the right pitch often and have to get as close as I can. Sometimes you have to blaze a trail and make the best of it.

At a certain point you have gather your chi and dive in, feel your way through and trust your judgement when it doesn't go wrong but try to be quick to recognize when it does and hopefully correct course before it goes too far south

The lockring above is a good example, if you can determine it works well enough to try it then do so with caution and diligence, keep an eye on it and see how it goes. In this case I would reinforce it well with loctite at least although I would go further, SG or even a tiny bit of JB.

If it holds together then all good, maybe only this one time but you have garnered judgement and experience that can mitigate some of this uncertainty next time.

There are usually only a few right ways, lots of wrong ways and a combination of those and more, my way.

I've made a pretty good living, won a heck of lot of races at the drag strip and solved many pita problems along the way.

thanks a lot, precious advice!!!

merziac 07-08-22 02:55 PM


Originally Posted by JackJohn (Post 22568306)
ok, I’ll start searching… :thumb:

You're going after messed up threads, its not going to be perfect no matter what you use, close will likely be good if you proceed with enough caution.

The exact tool will be best but I'm not holding up a project searching and waiting for a unicorn, especially if I can get plenty close and get it done.

All comfort zone and experience dependent of course, ongoing skill building being part of the goal as well.;)

merziac 07-08-22 03:03 PM


Originally Posted by JackJohn (Post 22568309)
thanks a lot, precious advice!!!

Tx, and you're welcome, just my 200c for what its worth.

All about building skills that will save, prevent and solve challenges like this when they come up.

If you lean in to these things with the right mindset, it can be very good experience coming out the other side with a far steadier hand that can really save you down the road.

bulgie 07-09-22 06:02 PM


Originally Posted by oneclick (Post 22567705)
Search for a Blue Point No 2 restore tool - there are a couple right now on that auction site..

Won't a hardened bearing cup dull your expensive thread file, without even being improved much in the process? Dunno, never tried it myself. And never will, unless someone else is paying for the file!

I have used thread files, but only on bolts and other non-hardened applications. Like on a cheap BB cup, but not on a Campy

I might try a fine triangle file on a Campy cup, since they're cheaper and easier to come by. Filing a thread with a triangle file takes more skill and good eyesight, but you can concentrate your filing on only the part of the thread that needs filing. Harder to do that with a thread file, that files on several threads at once. The triangle file needs to be a fine one because coarse files have too much of a radius where the two sides of the triangle meet. They can't file down into the bottom of the thread "valley".


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