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dura ace BB replacement

Old 10-29-10, 03:43 PM
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dura ace BB replacement

My old 7800 BB has seen better days. Was looking to replace it. will the new 7900 stuff work? Or even the ultegra 6700? Or do I need to grab a 7800 set somewhere?
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Old 10-29-10, 04:00 PM
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The BB I think should but not the components. The 7900 group is not interchangeable with 7800 series as the lever ratios have changed as well as the deraileurs and offset of the crank set, we just built a bike w DI 2 and the 7800 brakes seamed to work fine with the rest of the 7900. Good luck
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Old 10-30-10, 01:23 AM
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octolink is not backed by more than a few lengths of bb,
square taper you have many options.
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Old 10-30-10, 08:36 PM
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I presume you're talking about the outboard bearings that work the hollowtech crankset.
Any Shimano road bottom bracket (7900, 7800, 6700, 6600, etc.) will work for your 7800 cranks. Other manufacturers units, such as FSA) will work too, but be watchful of bearing width. You may need shims. If you stay with Dura-Ace or Ultegra, though, you can't go wrong.

I'm very satisfied with 7800, 7900 should be at least as good, and the only drawback to Ultegra is a few more grams. Also, your local shop may be able to simply replace the bearings in your existing cups.
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Old 10-30-10, 08:40 PM
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Originally Posted by fietsbob
octolink is not backed by more than a few lengths of bb,
square taper you have many options.
7800 is not octalink
Originally Posted by nwbikeman
The BB I think should but not the components. The 7900 group is not interchangeable with 7800 series as the lever ratios have changed as well as the deraileurs and offset of the crank set, we just built a bike w DI 2 and the 7800 brakes seamed to work fine with the rest of the 7900. Good luck
the op wants a new BB, not a new set of shifters.


Just get any set of shimano road outboard BB cups. Be it tiagra, 105, ultegra or DA, they're all interchangeable between the previous 4500, 5600, 6600, 7800 and current 5700, 6700 and 7900 BB cups.

the best deal, by far is ultegra, but if you want DA BB cups and ceramic bearings, then I won't stop you.
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Old 10-30-10, 09:19 PM
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So you see, not everyone lives by the Shimano product Number code.
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Old 10-31-10, 01:00 PM
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Originally Posted by fietsbob
So you see, not everyone lives by the Shimano product Number code.
You could have at least looked up what 7800 was before posting.

To the OP's question, here are some current options that will work:

Dura Ace 7900 Bottom Bracket
Ultegra 6700 Bottom Bracket
105 5700 Bottom Bracket
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Old 10-31-10, 03:07 PM
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thanks all!

Ultegra 6700 it is.

i appreciate the assistance.
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