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Old 06-05-07, 09:14 PM
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cascade168
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One thing that should be considered is that, despite standards, your BB tube may just be a loose fit. In any machining operation, taps and dies do not last indefinitely. When cutting tools approach the end of their useful life the cuts are just not as sharp.

The result of this is that some threaded fits are tighter than others, based on the condition of the cutting tools. If you get a BB tube that was tapped with an aging tap it may be a bit loose. If it is loose at all then it's going to creak. The easy way to detect this is to completely clean your threads on the BB and the BB tube and see just how easy or difficult it is to screw in the BB. You should be getting some resistance most of the way and it should be a bit difficult to thread in by hand. If it's relatively easy to thread in by hand - and I've seen this often - then it's a loose fit and there is a good chance it will creak if you don't do something.

While it's subject to debate, the way I fix this problem is to wrap the BB with some teflon tape. I have used one, two, or occasionally three layers to build up the BB threads. Try one layer, then two, then three. It will be pretty obvious when you have gone one layer too much. At that point I like to clean it all off and put on the proper thickness of tape that I now know is correct. Done properly, this will make the BB more and more difficult to install - just as it should be. You still grease the BB tube threads and put some on over the tape. This will eliminate BB installation related creaks. It will last a long time and will not be frozen solid when you get around to removing the BB in the future. You're just giving the threads a little tighter interference fit by using the tape.

I don't ever use any type of locking compound on BBs. It's just not necessary if you use teflon tape. It's important to remember that you wrap the tape around the BB in the opposite direction of the way it threads into the BB.
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