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Shimano 7800/7900 chainrings
Last Post 12/30/2013 10:46 PM by Hoshie S. 4 Replies.
Author Messages
Ride On

Posts:537

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12/29/2013 08:52 AM
Looking for some new chain rings. Any real difference between the Shimano 7800 and 7900 rings, other than price ? I understand I should get a matched set ( inner/outer ) of the 7800 or 7900 pairs. I'm pretty sure it is 7900 chain, if that matters. 130BC if that matters.
Master50

Posts:340

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12/29/2013 01:13 PM
I don't know if the bolt circles are the same but in terms of chainring quality. DA rings are forged I believe to enhance wear and hardness of the metal. DA rings should last longer but whether that justifies the cost difference I suppose depends on how long either lasts. I have chainrings that have 10 years of wear and have seen people wear them out in 2 seasons. In 1 case the guy never shifted out of his big ring so he tended to wear out the big ring just from severe chain angles when climbing in the big/big.
stinkyhelmet

Posts:94

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12/30/2013 10:04 AM
if you have a 7900 crankset, get the 7900 outer ring. Inner rings don't have ramps or pins so no need to get "matching". I currently use a SRAM 38 inner with no shifting issues. I have used 105, ultegra and dura ace chains.....none of the same 7900 generation and no issues.

If you have anything else, get the 7800 outer. I used FSA 38 inner for years with no shifting issues. You can use a 7900 ring but it cosmeticaly looks hacked together...the arms aren't flush. Like this. http://i527.photobucket.com/albums/cc355/CAADHEAD/Road%20bike%20hall%20of%20fame/IMG_0358.jpg
Oldfart

Posts:511

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12/30/2013 01:51 PM
7900 rings, big rings have hollow mounting tabs. Really thick which makes them stiff which makes them shift better than flat rings. Pretty marginal shifting difference in my experience over any other good quality tings I have tried. I would select something that is both mechanically and aesthetically compatible. I think that DA rings are also 7000 series aluminum whereas many others are 6000 series and as such the Shimano rings last longer. I know that XTR rings last far far longer that Race Face rings. Twice as along for me.
Hoshie

Posts:134

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12/30/2013 10:46 PM
Check out wick werks rings...

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