# What's the largest campy 10-speed cassette that i can use?



## Speed_Metal

What's the largest campy 10-speed cassette that i can use with a regular sized rear derailleur and a regular 39-53 crank set?


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## Kerry Irons

*It depends*



Speed_Metal said:


> What's the largest campy 10-speed cassette that i can use with a regular sized rear derailleur and a regular 39-53 crank set?


A standard derailleur will handle the 29t largest cog with no problem, but it most likely would not have enough capacity to keep the chain under tension with a 39/12 or maybe a 39/13. If you never go into those combinations, then you can stick with a standard cage. For example most people who would need a 29t cog would get a 13-29 cassette, and so the 39/13 would be "off limits" due to cross chaining. If you want to be able to use the 39 with smaller cogs then you need a longer cage RD.


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## bikerjulio

Just use my rule. 30t total takeup is max with the std RD.

So, a 53/39 front it taking up 14 of those. Leaving 16 to go.

If you use a 29T large cog then 29 - 16 = 13.

So a 29 x 13 cassette will work.

All this also implies that the chain length has to be just right also.


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## David Loving

You can use a small rear der with a 13-29 if you don't cross chain. I'd use at least a medium though (I do).


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## soup67

David Loving said:


> You can use a small rear der with a 13-29 if you don't cross chain. I'd use at least a medium though (I do).


Can the cage be swapped out without replacing the whole derailleur?


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## Drew Eckhardt

soup67 said:


> Can the cage be swapped out without replacing the whole derailleur?


The spare parts catalog indicates that the long cage cannot be used on the short and medium derailleurs but omits any mention of conflicts between those which suggests that a short <-> medium interchange is officially supported.

Note however that prior to the current redesign Record and usually Chorus rear derailleurs affixed the cage with a bolt whilst lower level offerings sometimes had a stud on the cage which was retained via a clip.

Also note that at least some of the parts affixing the non-body end of the B-tension spring have at least two positions for more and less tension so changing cages may suggest an adjustment there.


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## David Loving

Report back on how it went if you try it, please


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## bikerjulio

soup67 said:


> Can the cage be swapped out without replacing the whole derailleur?


You don't need to change the cage. Just get the chain length right. It should look something like this:


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## soup67

I am trying to make this work on my wife's 2006 10sp Chorus Compact. I think I need a longer cage. Sounds like the medium should bolt on?


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## Walvis43

What's the largest campy 10-speed cassette that i can use with a regular sizedrear derailleur and a regular 34-50 crank set? 
I have a centaur 10sp from2008, and would like to use a 29-13. Is this possible?


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## bikerjulio

My pictures above were of a 50-34 crank.

There is a 2-part answer to your question.

If you want to be able to use both the big-big and small-small combinations (not that either is advisable), then my 31T max rule for a short cage RD applies.

So, since 16T are used in the chainrings, 15T is left for the cassette. If you start with a 29T big cog then (29-15) a 14T small cog is the smallest that can be used.

The second part of the answer is that you can still use a 29-13 safely, it's just that the chain may go slack in the small-small combo. The picture above should help.

I just fitted a friends bike with a 12-29 and 50-34 up front. He understands that he's not going to use the 12 and 13T cogs while in the small ring.

As I said before, all of this ONLY WORKS if the chain length is right. It's useful to use a chain with a link, to make fitting to correct length easier. And in this case fit so that the big-big can be used safely without overextending the RD.


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## Walvis43

Thanks for this, Julio!


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## bikerjulio

One thing I forgot to mention is to back out the "H" screw for maximum clearance of the upper jockey wheel from the 29T cog.

Steps 12 and 13 here http://www.campagnolo.com/repository/documenti/en/10s_Rear_derailleur.pdf


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## Walvis43

Again, thanks for this. I just found a 30-12 cassette. Do you think it's too much for my CT crankset, standard cage?


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## bikerjulio

Walvis43 said:


> Again, thanks for this. I just found a 30-12 cassette. Do you think it's too much for my CT crankset, standard cage?


It will work, now I'm thinking that my friend's might have been a 30T not 29.

Size the chain to be safe in big-big, and realize that you won't be able to go small-small.


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## Walvis43

Great, Thanks!


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