BB thread differences...
03-01-13, 02:10 PM
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BB thread differences...
...at the risk of asking ANOTHER question that shows my lack of apparent "lack of knowledge", I'm going to anyway! 
I have been able to thread a Sugino CBB-103(BC 1.37 x 24t) bb into a 66mm bb shell. However an RPM BB7420(BC 1.37 x 24t) WILL NOT thread in. 
Is there a difference in the respective threads that would prevent the RPM unit from "going in?" The adj. side of the RPM goes in but the fixed side does not? Is this possible operator error?
I have been able to thread a Sugino CBB-103(BC 1.37 x 24t) bb into a 66mm bb shell. However an RPM BB7420(BC 1.37 x 24t) WILL NOT thread in. Is there a difference in the respective threads that would prevent the RPM unit from "going in?" The adj. side of the RPM goes in but the fixed side does not? Is this possible operator error?
03-01-13, 03:22 PM
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First make sure you have the threading directions right. Second there are differences in how 'full" the thread profile is. A BB cup with a tall/pointy thread profile might not fit in a shell cut with dull or low height thread profiles. Third dirt and grime in threads can cause hang ups. Fourth have you tried both BBs in another frame? Fifth I suspect your shell is a 68mm wide one (not 66) (minor nit pick admittedly). Sixth does the RPM not even start a tiny bit? Usually it takes a thread or two before things start to jam up. Seventh have you had any BB problems or work done? have you had a LBS look at it yet? Can't say what's going on without more info, and even then not having all in hand makes things difficult to place blame. Andy.
03-01-13, 04:30 PM
#3
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Did you just remove a prior BB yourself? or, is this a new to you used frame ,
which may have a buggered up CCW thgreaded side of the BB shell.
Dropping by a Proper, Bike Shop will allow them to chase, Ie clean up the potentially damaged threads,
using a frame tap set will be the best approach.
which may have a buggered up CCW thgreaded side of the BB shell.
Dropping by a Proper, Bike Shop will allow them to chase, Ie clean up the potentially damaged threads,
using a frame tap set will be the best approach.
03-01-13, 04:44 PM
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Mechanic/Tourist
This is new thread for previous issue: https://www.bikeforums.net/showthread...061-BB-removal-!
03-01-13, 09:17 PM
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@the OP: generally speaking, it is less confusing and considered more conscientious
when you start a thread on a particular problem, to stay with it on that same thread.
It is, of course, your choice as to whether you wish to do so.
I can assure you that going over your confusion again will result in no better answers
than you have already been given.........but you might get some additional confusion,
so what the hell.........
when you start a thread on a particular problem, to stay with it on that same thread.
It is, of course, your choice as to whether you wish to do so.
I can assure you that going over your confusion again will result in no better answers
than you have already been given.........but you might get some additional confusion,
so what the hell.........
03-01-13, 09:37 PM
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03-02-13, 08:46 AM
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This is new thread for previous issue: https://www.bikeforums.net/showthread...061-BB-removal-!
03-02-13, 09:00 AM
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First make sure you have the threading directions right. Second there are differences in how 'full" the thread profile is. A BB cup with a tall/pointy thread profile might not fit in a shell cut with dull or low height thread profiles. Third dirt and grime in threads can cause hang ups. Fourth have you tried both BBs in another frame? Fifth I suspect your shell is a 68mm wide one (not 66) (minor nit pick admittedly). Sixth does the RPM not even start a tiny bit? Usually it takes a thread or two before things start to jam up. Seventh have you had any BB problems or work done? have you had a LBS look at it yet? Can't say what's going on without more info, and even then not having all in hand makes things difficult to place blame. Andy.
1st:I believe that I have the threaded directions correct! I will have the LBS check that today!
2nd:Tall and pointy vs dull/low threads...LBS will check that today!
3rd: The shell will be properly cleaned with solvent and fine wire brush today!That makes sense!
4th: Don't enjoy the luxury of a 2nd frame. LBS will assist with that today!
6th: the RPM adj. side threads in smoothly but the drive side bind 2-3 turns in! perhaps OP error! LBS will check that today!
7th: No BB work done except to remove loose bb, etc.
Again, after a careful and reasonable attempt at these tasks myself the LBS will assist!
Unfortunately, those of us that are novices that enjoy doing these things ourselves we do ask questions that make evident our "apparent lack of knowledge."
03-02-13, 09:07 AM
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03-03-13, 08:15 AM
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Didn't you describe in another thread that you discovered the threading to be messed upon the fixed cup side? This could be the reason.
As pointed out by others: You'll get better answers if you contain your questions to the same thread. This allows everybody to have a more comprehensive view of your challenge.
Good luck to you.
As pointed out by others: You'll get better answers if you contain your questions to the same thread. This allows everybody to have a more comprehensive view of your challenge.
Good luck to you.
