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Square taper BB spindle Female threads

Old 10-07-19, 10:33 AM
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merlinrkd
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Square taper BB spindle Female threads

I have a wrecked Specialized aluminum frame. I'm trying to extract the Shimano square tapered BB cartridge. The lock rings are chewed up so I'm not confident I can get a secure bite with the lock ring tool. My tool is the Park BBT-2. I'm thinking if I could get a 2-3" long bolt I could could bolt thru the tool and pull the tool tight on the ring. Then use a BFW on the tool to extract the ring. I've looked the crank bolt and I'm not sure what the thread and diameter are. Is it a standard size bolt I could get at the hardware or NAPA store to bolt into the end of the spindle?

Thx
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Old 10-07-19, 10:45 AM
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Bill Kapaun
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Like this? You need M8x1.0 bolts, not the more common M8x1.25mm.
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Old 10-07-19, 10:49 AM
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merlinrkd
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That looks exactly right! And yes I do have a bucket of the common 8X1.25 from my Saab days. I'll have to safari around town for 1.0mm.
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Old 10-07-19, 10:53 AM
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Bill Kapaun
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A couple different bolt lengths are handy since spindle lengths can vary.
I use enough washers to give me good purchase without running out of thread.
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Old 10-07-19, 12:37 PM
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I use a bar clamp across BB, tool and all, holds the tool in nicely. Just loosen it after you break the BB loose, you probably won't need it further once the BB starts moving..
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Old 10-07-19, 01:39 PM
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The M8 bolts w/1mm thread pitch is sometimes listed as "fine" thread.

A 2" length w/washer or spacers is about right. I use a 40mm length bolt with about 8mm of spacers on a 118mm BB. This is with a Pedros BB tool.
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