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TAW
05-01-2008, 02:24 PM
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!

Jeff N.
05-01-2008, 03:07 PM
Not to worry...they'll spin just fine. Jeff N.

tbushnel
05-01-2008, 03:53 PM
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.

Grant McLean
05-01-2008, 04:29 PM
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

dvs cycles
05-01-2008, 07:31 PM
Those concerned about the drag usually go for the ceramic replacements.$$$

vaxn8r
05-01-2008, 10:21 PM
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.

Der_Kruscher
05-02-2008, 01:39 AM
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...

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!

RudAwkning
05-02-2008, 09:05 AM
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.