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I need to remove the bottom bracket bearing cups from my 2010 Athena groupset. Do they both unscrew anti-clockwise, or is one side different (and which one)?

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  • Unfortunately, there is not a single rule. If the bearings are standard "internal" bearings (everything fits inside the bottom bracket cylinder at the bottom of the frame), then the left side cup unscrews "normally". Depending on the whims of the manufacturer, though, the right side cup may be "backwards" or may not be (though most likely it is backwards). If you're lucky there is thread sticking out and you can test the thread (run your thumbnail through it as you "unscrew" your hand) to see which way it goes. When you get to fancy external bearings and the like, all bets are off. Sep 24, 2015 at 23:47
  • I've come to understand that the issue is English v Italian threading, where English is more usual. Sep 26, 2015 at 8:42
  • I think it's also the case that some older English BBs are "normal" on both sides, relying on a lock ring to hold the one side in place. And I'd not be surprised to find some relatively new BSOs similarly threaded, relying on thread lock compound to prevent the cup from turning -- I vaguely recall that that's been done occasionally. Sep 26, 2015 at 12:38

2 Answers 2

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For English-threaded Ultra Torque, the right (chain) side cup unscrews clockwise, the left one anti-clockwise. For Italian, both unscrew anti-clockwise.

It's most likely that you have English. I don't know how you could tell for certain though without asking your bike maker, measuring the size, or seeing which way they actually unscrew.

For the reason why the English is 'correct' see the link in the comment below.

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  • It all has to do with precession. Sep 25, 2015 at 11:54
  • The question was: which BB does the bike have. Saying "it might have either" doesn't really help.
    – Móż
    Sep 27, 2015 at 3:57
  • The question wasn't which BB does the bike have? The question was, given it is Athena, which way does it unscrew? As there are English and Italian Athena BB's, you need to establish which you have in order to answer the question. Nov 12, 2015 at 11:02
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I used google: from the Campag website the Athena groupset has an Over-Torque BB (pdf) with a BSA thread. Further searching reveals that BSA is an english thread, which is the modern standard. So yes, the left hnd cup unscrews anticliockwise and the right hand one clockwise.

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    Campag also sell Ultra Torque bearing cups with an Italian thread though, and 2010 Athena was Ultra Torque. Sep 28, 2015 at 6:33
  • 2
    Reasons to hate Campag #999...
    – Móż
    Sep 28, 2015 at 7:10

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