Anyone know the difference between...

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03-10-11 | 10:58 AM

Wrench_Monkey

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Anyone know the difference between...

Dura Ace A-type versus B-type, specifically where chainrings are concerned?

03-10-11 | 11:20 AM

desertdork

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I believe one is designed for use with 42t inner rings, while the other is designed for 39t inner rings.

03-10-11 | 11:00 PM

vredstein

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From: Tucson, Arizona

Bikes: '02 Lemond Buenos Aires, '98 Fuji Touring w/ Shimano Nexus premium, '06 Jamis Nova 853 cross frame set up as commuter, '03 Fuji Roubaix Pro 853 back up training bike

Quote:

Originally Posted by Wrench_Monkey

Dura Ace A-type versus B-type, specifically where chainrings are concerned?

https://www.sheldonbrown.com/dura-ace.html#chainrings

Set "A" uses a 42 tooth small ring, and a corresponding "A" type 53.
Set "B" uses a 39 tooth small ring, and a choice of "B" type 52 or "B" type 53

03-11-11 | 02:08 AM

fietsbob

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yea shift pins and gates are in different spots, depending on the inner chain ring.

03-11-11 | 07:31 PM

DOS

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I have mixed A Type big ring with B type small ring with no discernible negative consequence.

03-11-11 | 08:49 PM

jasonrobo02

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Bikes: 2006 Bianchi 928 Record and 2002 Bianchi Axis 1x9

I agree with all the posters above. The A and B designations refer to the chainring combinations that will provide optimal performance. But it's not like your bike will explode if you mix an "A" big ring with a "B" little ring.