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Old January 10th 17, 10:18 PM posted to rec.bicycles.tech
AMuzi
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Posts: 13,447
Default Need advice on bottom bracket repair

On 1/10/2017 2:24 PM, wrote:
On Tuesday, January 10, 2017 at 11:51:53 AM UTC-8, Theodore Heise wrote:

Yes, another "yikes!" on this. Getting beyond my skill/comfort
level...


Ted, these people have been inundating you with all of these things that they've never actually done themselves. So they are advice and not instructions. Andrew Muzi is the only professional.

Usually the reason that a bottom bracket cup with not pull out is because there was something in the threads when it was inserted. Or they used the incorrect kind of Loctite.

Since your bike is polished aluminum I assume you've been careful with it and not left it out in the weather.

If you carefully work the adjustable cup back and forth and it doesn't gradually start turning out take it to a COMPETENT bike shop. Even if you force it out eventually there's the chance that you can damage the frame's finish. A good shop will have shop quality tools that made this a whole lot less likely.

As I said before, in one case I removed the BB from the fixed side and then sawed the adjustable cup down ALMOST to the threads and then the cup would distort enough to allow it to come out. But that was an awful job and I certainly wouldn't recommend it. In another case the incorrect loctite was used in a bottom bracket on a carbon frame and it was twisted so hard that the liner broke loose from the frame and spun in the bottom impossible to remove. I'm still deciding to take that frame down to Santa Cruz so that the carbon people would forcibly remove the entire liner and repair it back to normal. I NEVER use loctite that hasn't been applied to a new bottom bracket by the manufacturer.

There is no need in English bottom brackets anyway. And the new sealed units do not walk out anyway. But tandems are a special case and I don't think you can get a sealed BB for them. The spindle length on a tandem is peculiar to the specific bike.


In fact there are not only tandem cartridge BB units in both
spline and square, those have been oem standard for 30 years.

p.s. Mr Slocumb's experience with airplanes and other
equipment makes him very qualified to comment about
mechanical service processes.
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


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