# P2C Rear Cassette



## gmarch (Apr 18, 2007)

Hi all...

I want to change my rear cassette, and I've been looking on ebay for a Dura Ace 12/27. As with most things, the more you read, the less you know.

So, now I'm unsure of what the "CS-xxxx" specification means. I found one on ebay and it says it's a "CS-7800". I see references to CS-7700 and others.

Can anyone explain this to me? And, more specifically, explain which one I would need? My P2C is a 2007 model with the Easton wheels, 11/23 Ultegra rear cassette and chain (Dura Ace everything else, i.e. stock setup).

Are there other specifications I should look for in addition to the "CS" number?

Thanks very much,

/greg


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## chrissa (Nov 12, 2006)

I believe the CS-7700 series are the older 9 speed Dura Ace cassettes. CS-7800 are the current 10 speed Dura Ace cassettes. You most likely want the CS-7800.

Maybe someone else can answer if there has been any specific changed to the CS-7800 over its product life so far?

Chris.


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## gmarch (Apr 18, 2007)

Chris,

Thanks. I also just got this from the Cervelo forum:

7800 is 10sp

7700 is 9sp

6600 is ultegra 10sp

6500 is ultegra 9 sp

/greg


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