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  #1  
Old 05-01-2008, 01:24 PM
TAW TAW is offline
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Dura Ace Bottom bracket

In switching over to the newer Dura Ace cranks (7800) on both of my bikes, it seems to me that the new bottom brackets have more drag and don't spin as well as the older style. Anyone noticed this? Do they "loosen up" over time?

Thanks!
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  #2  
Old 05-01-2008, 02:07 PM
Jeff N. Jeff N. is offline
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Not to worry...they'll spin just fine. Jeff N.
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  #3  
Old 05-01-2008, 02:53 PM
tbushnel tbushnel is offline
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Pw

I think phil wood makes replacement cartridge bearings for the 7800 crankset. I don't know if you need to replace them but have heard that the phils are an improvement.
Ted.
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  #4  
Old 05-01-2008, 03:29 PM
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Grant McLean Grant McLean is offline
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Quote:
Originally Posted by TAW
In switching over to the newer Dura Ace cranks (7800) on both of my bikes, it seems to me that the new bottom brackets have more drag and don't spin as well as the older style. Anyone noticed this? Do they "loosen up" over time?

Thanks!
The drag you feel the seals doesn't affect the riding performance.
Were you under the impression that Shimano's top of the line bearings aren't any good?

It's under the full weighted load that matters, when hundreds of pounds of force are applied.

...unless all you do is move your crankarms with your fingers?

Bearings are very efficient.


-g

Last edited by Grant McLean; 05-01-2008 at 03:34 PM.
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  #5  
Old 05-01-2008, 06:31 PM
dvs cycles dvs cycles is offline
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Those concerned about the drag usually go for the ceramic replacements.$$$
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  #6  
Old 05-01-2008, 09:21 PM
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vaxn8r vaxn8r is offline
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Originally Posted by dvs cycles
Those concerned about the drag usually go for the ceramic replacements.$$$
Until the ceramaic bearings wear out the races because they are so dang hard. Then you start over and buy another BB.
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  #7  
Old 05-02-2008, 12:39 AM
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Der_Kruscher Der_Kruscher is offline
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Have the BB shells been faced?

Maybe a dumb question but external BB's can bind if the BB shell faces aren't totally parallell. Maybe this isn't the "issue" you're having but I just thought I'd throw it out there...

Quote:
Originally Posted by TAW
In switching over to the newer Dura Ace cranks (7800) on both of my bikes, it seems to me that the new bottom brackets have more drag and don't spin as well as the older style. Anyone noticed this? Do they "loosen up" over time?

Thanks!
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  #8  
Old 05-02-2008, 08:05 AM
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RudAwkning RudAwkning is offline
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Quote:
Originally Posted by vaxn8r
Until the ceramaic bearings wear out the races because they are so dang hard. Then you start over and buy another BB.
Been there. They lasted one season. Never again. And that was just the BB. I can only imagine how long they'd last in a wheelset.
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