It's there a standard size bolt for bottom bracket spindles?
10-08-21, 05:00 PM
#1
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It's there a standard size bolt for bottom bracket spindles?
Title says it all. I ordered a cup and cone one from eBay and the threading inside the spindle is damaged, I think. Either that or they're the wrong size bolts.
10-08-21, 06:06 PM
#2
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...If it's a square taper spindle, the threading is pretty standard, just the heads of the bolts come in different sizes.
...If it's a square taper spindle, the threading is pretty standard, just the heads of the bolts come in different sizes.
10-08-21, 06:15 PM
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The threading is usually M8x1.0mm. This is a finer thread than the more commonly available M8x1.25mm but bike shops or better hardware and industrial supply shops will have the proper bolts. As noted, the head configuration can vary among bb and crank makers.
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10-08-21, 06:46 PM
#4
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Thanks guys. I want to order a tap to clean out the threads and needed to know what size.
10-08-21, 07:31 PM
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M8 x 1.0 mm, but the bolt length varies.
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10-09-21, 04:58 AM
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If this is a used spindle from ebay, they may have used the wrong tool to pull the crank and damaged the threads inside the spindle. As others have said, is is a M8 x1.0mm. Good luck with using a tap, the spindles are hardened steel.
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10-09-21, 05:58 AM
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Harder than usual, but a better word is toughened, should be no problem for the really hardened tap to clean out
buggered threads. A dollop of oil is a good idea when using the tap.
buggered threads. A dollop of oil is a good idea when using the tap.
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10-09-21, 07:44 AM
#8
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10-09-21, 07:48 AM
#9
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It is supposedly new, and the cups s and bearings look new, but I suspect the spindle is "refurbished". Seems to have been coated with something that made the threads unusable. I could be wrong. It's not worth returning, so I'm going to mess around with it. I'll post an update and some photos when I've got it fixed or destroyed.
