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Correcting a cross-threaded bottom bracket?



 
 
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  #1  
Old October 12th 15, 10:06 AM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
Default Correcting a cross-threaded bottom bracket?

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers
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  #2  
Old October 12th 15, 01:28 PM posted to rec.bicycles.tech
AMuzi
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Posts: 13,447
Default Correcting a cross-threaded bottom bracket?

On 10/12/2015 4:06 AM, Sir Ridesalot wrote:
I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


A piloted tap set can remove occlusions and ensure both
threads are on the same axis.

Taps however are subtractive machining. You won't have any
more thread height than now, and likely less. Some
inspection, measurement, analysis and advice from someone
who does this work regularly would be a good start.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


  #3  
Old October 12th 15, 01:47 PM posted to rec.bicycles.tech
[email protected]
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Posts: 6,374
Default Correcting a cross-threaded bottom bracket?

1 April, 1971

OCCLUSIONS !!! ***rrr44DSx00))&$))) !!

yeah el tapo ! you need expert hands for starting the tap...as AM sez

blue locktite on 2 prepared clean surfaces will hold that area together no prob.

and if the BB falls out...go with red.

I had spelts for dinner...

then we skinned the nabs weimeraner for winter gloves

https://www.google.com/#q=occlusions

  #4  
Old October 12th 15, 02:44 PM posted to rec.bicycles.tech
John B.[_6_]
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Posts: 2,202
Default Correcting a cross-threaded bottom bracket?

On Mon, 12 Oct 2015 02:06:12 -0700 (PDT), Sir Ridesalot
wrote:

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.p...-brackets.html
--
cheers,

John B.

  #5  
Old October 12th 15, 03:00 PM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
Default Correcting a cross-threaded bottom bracket?

On Monday, October 12, 2015 at 9:44:49 AM UTC-4, John B. wrote:
On Mon, 12 Oct 2015 02:06:12 -0700 (PDT), Sir Ridesalot
wrote:

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.p...-brackets.html
--
cheers,

John B.


I'm taking the frame to a shop tomorrow(closed today due to it being Thanksgiving Monday here in Canada) and see what they charge to chase the threads.. The threadless bottom braket might be the easiest way to go though. It's a very nice frame ideally suited for conversion to a drop bar touring bike for fire/logging/mining roads touring.

Cheers
  #6  
Old October 12th 15, 03:34 PM posted to rec.bicycles.tech
[email protected]
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Posts: 445
Default Correcting a cross-threaded bottom bracket?

On Mon, 12 Oct 2015 07:28:14 -0500, AMuzi wrote:

On 10/12/2015 4:06 AM, Sir Ridesalot wrote:
I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


A piloted tap set can remove occlusions and ensure both
threads are on the same axis.

Taps however are subtractive machining. You won't have any
more thread height than now, and likely less. Some
inspection, measurement, analysis and advice from someone
who does this work regularly would be a good start.

And an application of locktite to the repaired thread on assembly
would be a good second step. I had a Raliegh Twenty with a
cross-threaded bottom bracket (fixed cup) that I got the thread
cleaned up on resulting in about halth thread depth (or less) and it
would not stay tight. I took it apart, cleaned it with acetone,
sprayed it with loc-tite prime-bond, and applied a couple drops of
locktite stud mount. It never moved again. That was a good 10 years
ago.
  #7  
Old October 12th 15, 08:46 PM posted to rec.bicycles.tech
Frank Miles
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Posts: 40
Default Correcting a cross-threaded bottom bracket?

On Mon, 12 Oct 2015 20:44:44 +0700, John B. wrote:

On Mon, 12 Oct 2015 02:06:12 -0700 (PDT), Sir Ridesalot
wrote:

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.p...-brackets.html


Ooohhh! Thanks! Never saw one of those before. We bought my son a used bike
(from a local used-gear store), only to discover recently that the right side's
threads were toast. He took it to a local bike shop - they charged him $100
for chasing the threads and replacing the good sealed bearing unit with a
crappy one that didn't even fit properly. In an act of desperation I drilled
and tapped a couple of setscrew holes and installed an old non-sealed hub that
kinda fit (threads still loose - just not enough metal left). This has worked
for a few months without any issues but eventually something like this threadless
version will probably be needed.

Again - thanks!
  #8  
Old October 12th 15, 09:39 PM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
Default Correcting a cross-threaded bottom bracket?

On Monday, October 12, 2015 at 3:48:50 PM UTC-4, cassiope wrote:
On Mon, 12 Oct 2015 20:44:44 +0700, John B. wrote:

On Mon, 12 Oct 2015 02:06:12 -0700 (PDT), Sir Ridesalot
wrote:

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.p...-brackets.html


Ooohhh! Thanks! Never saw one of those before. We bought my son a used bike
(from a local used-gear store), only to discover recently that the right side's
threads were toast. He took it to a local bike shop - they charged him $100
for chasing the threads and replacing the good sealed bearing unit with a
crappy one that didn't even fit properly. In an act of desperation I drilled
and tapped a couple of setscrew holes and installed an old non-sealed hub that
kinda fit (threads still loose - just not enough metal left). This has worked
for a few months without any issues but eventually something like this threadless
version will probably be needed.

Again - thanks!


According to that manufacturer make sure your bottom bracket shell is no more than 68mm wide otherwise this threadless BB won't work.

Cheers
  #9  
Old October 13th 15, 08:42 AM posted to rec.bicycles.tech
John B.[_6_]
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Posts: 2,202
Default Correcting a cross-threaded bottom bracket?

On Mon, 12 Oct 2015 13:39:35 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, October 12, 2015 at 3:48:50 PM UTC-4, cassiope wrote:
On Mon, 12 Oct 2015 20:44:44 +0700, John B. wrote:

On Mon, 12 Oct 2015 02:06:12 -0700 (PDT), Sir Ridesalot
wrote:

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers

Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.p...-brackets.html


Ooohhh! Thanks! Never saw one of those before. We bought my son a used bike
(from a local used-gear store), only to discover recently that the right side's
threads were toast. He took it to a local bike shop - they charged him $100
for chasing the threads and replacing the good sealed bearing unit with a
crappy one that didn't even fit properly. In an act of desperation I drilled
and tapped a couple of setscrew holes and installed an old non-sealed hub that
kinda fit (threads still loose - just not enough metal left). This has worked
for a few months without any issues but eventually something like this threadless
version will probably be needed.

Again - thanks!


According to that manufacturer make sure your bottom bracket shell is no more than 68mm wide otherwise this threadless BB won't work.

Cheers


And the threaded bottom bracket standard seems to be 68mm for the
British, French, ISIS and Swiss bottom brackets. the Italian is 70mm.
In addition, the 'Bottom Bracket Tool' comes in two flavors. the
"Threading and Facing" Tool" or the "Facing Tool", so essentially any
shop that "does bottom brackets" has the ability of cutting the bottom
bracket a bit narrower, if necessary.
--
cheers,

John B.

  #10  
Old October 13th 15, 10:16 PM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
Default Correcting a cross-threaded bottom bracket?

On Monday, October 12, 2015 at 5:06:19 AM UTC-4, Sir Ridesalot wrote:
I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers


I used an old pair of bottom bracket cups to make a tool to cleanup the threads. I cut some grooves into a fixed cup and made a spacer to fit inside the fixed cup and adjustable cup. I screwed the adjustable cup inmost of the way and then started the fixed cup supported by the internal spacer as I threaded the fixed cup in I backed out the adjustable cup which with the spacer kept the fixed cup square to the bottom bracket shell. Surprisingly, by working very slowly on it, it worked and I was able to cleanup the cross threading and then install a sealed cartridge bottom bracket. Everything tightened up okay. i guess my next step will be to strip the frame and repaint it. i also need to either get a riser quill stem, a quill to threadless stem adapter and stem, or an adjustable stem to get the bars uo to where I most prefer them. A shakedown ride today shows that all's well except I'd prefer a bit longer reach on my stem.

Cheers
 




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