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Swap 7900-28h rear hub for 6600-28h hub?

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Swap 7900-28h rear hub for 6600-28h hub?

Old 10-10-18, 08:36 PM
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Swap 7900-28h rear hub for 6600-28h hub?

I have a 7900 28h rear hub that cracked. I have found an Ultegra 6600 28h rear hub and would like to swap in the 6600 hub with the same spokes and rim. Here are the specs. They are close but not a perfect match.
Opinions?




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Old 10-10-18, 09:56 PM
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The differences are insignificant. Swap away.
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Old 10-12-18, 12:45 PM
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Originally Posted by Jeff Wills
The differences are insignificant. Swap away.
Thanks for the info. I think I am going to overpay for the 6600 28h hub, (it is NOS) but finding a 7900 28h rear hub may be difficult and using the same rim and spokes would be simple.
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Old 10-12-18, 01:05 PM
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Run those numbers through a spoke length calculator to see what length you need to have the nipples take up. It's probably within a couple of mm, which is usually easily taken up by the nipple.
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Old 10-12-18, 01:10 PM
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You can use most any online spoke calculator to compare the 2 hubs and note the difference.

FBinNY's rule of the thumb was for every 10mm difference in offset equaled about 1mm in spoke length.
For crossed spokes, the greater the number, the less difference in flange diameter, with radial (0 cross) obviously have the greatest effect.
Radial spoke length will be 1/2 the difference of hub diameter.

Unless your spoke lengths were borderline in length, you should be just fine.
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Old 10-12-18, 01:50 PM
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I will use a spoke calc to see what it says. It's radial NDS and 2x DS. I ran the calculator. It's within 1/10 of a millimeter.

Last edited by tmh657; 10-12-18 at 03:35 PM.
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Old 10-14-18, 07:10 AM
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Gonna agree with Jeff Wills (always a good bet btw).

Most of the difference in spoke length requirements are due to rim differences.
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