# Dura Ace 7900 (compact) with SRAM cassette



## DionSF (Apr 22, 2009)

SRAM's new Apex 11 - 32 cassette intrigues me. I'm registered for the Death Ride and have 32 on the back would be sweet.

Does anyone know if the 7900 rear derailleur can handle a 32 tooth ring?


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## Wheelman55 (Jul 10, 2009)

Shimano claims that it will work up through a 28.


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## DaveT (Feb 12, 2004)

DionSF said:


> SRAM's new Apex 11 - 32 cassette intrigues me. I'm registered for the Death Ride and have 32 on the back would be sweet.
> 
> Does anyone know if the 7900 rear derailleur can handle a 32 tooth ring?


I'm running a 6700 Ultegra group very similar to 7900 and am using an 11-30 cassette with no issues. One of the two problems that you will run into, and won't be able to find out if it will or will not work on your bike until you install the cassette, will be if the upper jockey wheel will clear the cassette teeth. This can vary from bike to bike due to chain stay length and exact location of the rear derailleur mount, so one person's success can be another's failure. The other problem, chain wrap, can be figured mathematically.


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## Clevor (Sep 8, 2005)

DaveT said:


> I'm running a 6700 Ultegra group very similar to 7900 and am using an 11-30 cassette with no issues. One of the two problems that you will run into, and won't be able to find out if it will or will not work on your bike until you install the cassette, will be if the upper jockey wheel will clear the cassette teeth. This can vary from bike to bike due to chain stay length and exact location of the rear derailleur mount, so one person's success can be another's failure. The other problem, chain wrap, can be figured mathematically.


Is that an 11-30 SRAM cassette? Isn't there shifting issues with SRAM that has to do either with the cogset, chain, or crank? Mainly in that it doesn't shift as good as Shimano.

I am using a 53/39 and 12-25 and need some lower gearing. I like the Campy cogs since on a 12-27 the last two cogs are 25 and 27, but on the Shimano it is 24 and 27. Ideally I'd like a 26 and maybe 28 or a bit lower. Anybody has any suggestions?


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## DaveT (Feb 12, 2004)

Clevor said:


> Is that an 11-30 SRAM cassette? Isn't there shifting issues with SRAM that has to do either with the cogset, chain, or crank? Mainly in that it doesn't shift as good as Shimano.
> 
> I am using a 53/39 and 12-25 and need some lower gearing. I like the Campy cogs since on a 12-27 the last two cogs are 25 and 27, but on the Shimano it is 24 and 27. Ideally I'd like a 26 and maybe 28 or a bit lower. Anybody has any suggestions?


It's an IRD cassette and no shifting or noise issues at all. I used an SRAM 11-28 cassette previously and it was merely too noisy.

Another, though expensive alternative would be to use a compact crankset.


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