# Campagnolo Chorus 11 Speed Cassette Question



## thaugen (Aug 20, 2007)

I am currently running a Shimano Ultegra 50/34 with a 12-25 rear cassette on my road bike. I just purchased a new Canyon Ultimate CF with Campagnolo Chorus 11. Unfortunately, the compact 50/34 was not available so I went with a standard 53/39 crankset. The standard front crank is paired with a 12-25 rear cassette.

I live in Switzerland and do a fair bit of climbing. Presently my climbing gear is a 34/25 and I've never had any trouble on even the steepest climbs. On my new bike the climbing gear will change to a 39/25 which might not be enough for some of the steep stuff. 

I am considering changing the rear cassette to either a 12-27 or a 12-29. Any thoughts on the pros and cons of these two options?

Thanks in advance for your help!


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## bigbill (Feb 15, 2005)

I use a 12-27 with a standard crankset but I don't have anything "epic" as far as climbs go. I can probably recall each time I have used the 27, mostly really steep short stuff. The wider the range of gears, the bigger the jump between cogs. With 11 speed it's not as noticeable but if you did a lot of riding on flatter terrain you might want a smaller cassette. In your case, the 12-27 or 29 sounds like it would be the right choice with longer climbs in really low gears and fast descents on high gears. Be careful of the 53/29 combination, just remember to think ahead when approaching a climb.


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## veloci1 (Nov 29, 2005)

you could also buy a smaller inner front ring. that will help you across all gears. i think they are hard to find, but,i am sure you LBS will find you one. i think they might have 38 or 36 for a standard crqnk.


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## C-40 (Feb 4, 2004)

*not for Campy...*



veloci1 said:


> you could also buy a smaller inner front ring. that will help you across all gears. i think they are hard to find, but,i am sure you LBS will find you one. i think they might have 38 or 36 for a standard crqnk.


Campy;s 135mm BCD limits the inner ring to 39T.


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## fallzboater (Feb 16, 2003)

A 34/25 is the equivalent of a 39/29, but only you can know if you need that low of a gear. If you like the compact gearing, you can sell your Chorus crank and buy a Campy or any other brand 10 speed compact crank, which is what I'd recommend.


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## BryanSayer (Sep 22, 2009)

I concur. Just get the compact crank and sell your existing crank. ShinyBikeParts has good prices, at least against the dollar.


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## tom_h (May 6, 2008)

delete, double post


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## tom_h (May 6, 2008)

With 50/34 and 12-25 rear cassette , 
lowest gear = 34 chainring + 25 cog = *36 gear-inch*.

11sp Campy 53/39,
39 chainring + 27 cog = *38 gear-inch*, just 5.6% "harder".
39 chainring + 29 cog = *36 gear-inch*, exactly same gearing as your Shimano setup.

I've read that 2009 Campy 11 rear derailleurs require a minor factory-approved and supprted modification to be compatible with 12-29 cassette, but that 2010 RD are fully compatible "as is".

Considering how expensive it would be to replace the Campy crank set, choosing the 12-27 or 12-29 cassette option makes sense to me ... 

Also, 53 - 12 will give you a plenty high gear for pedaling downhill.


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## thaugen (Aug 20, 2007)

Thank you for your helpful and informative replies. 

Yesterday I tried to ride my loop without my 25 and had one hill that was very uncomfortable without the climbing gear. I really like my present set-up and agree the best option is to go with the 12-29 with the 53/39. 

I was just wondering about those 3 tooth jumps in the 12-29. Will that create some strange shifting or gaps in my gear choice?


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## AlexRandall (Nov 29, 2008)

By the time you get to the 3 tooth jumps you will want them. Also as you get to that area you need a larger gap in teeth to maintain the same % change in gear ratio


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