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-   -   From an 11-23 to a 12-27 Cassette. Will I need to change my chain? (

DCnoJ 05-08-10 07:25 PM

From an 11-23 to a 12-27 Cassette. Will I need to change my chain?
I have the Super Record Group Set with a compact crank. I'd like to switch between an 11-23 cassette to a 12-27. Will I have to change to a longer chain? If so, can I make an initial change so that I can continually switch between cassettes? Is that even possible?

Thanks in advance.

Servo888 05-08-10 07:41 PM

You should use a longer chain with the 12-27, as recommended by manufacturers. Basically running too short of a chain will damage the rear derailleur over time when using big+big sprocket combinations.

But, if you avoid cross chaining with the big+big combination, you can definitely run the same (short) chain.

ericm979 05-08-10 07:57 PM

Try to shift (very gently) into the big chainring/big cog. If the chain's too short to make it, you need a longer chain.

I would not recommend "trying to remember" not to shift into it. You'll do it by accident when you're tired on a long ride or busy paying attention during a race. And when you do it'll cost you way more than a new chain would.

goodtimes5 05-08-10 08:33 PM

Yes (probably).

jdott 05-08-10 10:36 PM

The chain should be adjusted to the small-small, which did not change. The problem is that with a compact and a 27, your der will be crazy stretched to the limit. But if you lengthen the chain, small-small will be rubbing very badly. So, it will never be all the way 'right', but rubbing on small-small is way less of a problem than an exploding der when you cross-chain in the other direction.

jdott 05-08-10 10:37 PM

actually, now that I actually read your entry - with a 12 you may actually be able to get it really close.

DaveSSS 05-09-10 07:10 AM

If you followed Campy's instructions for adjusting chain length, you would have no problem at all. Campy suggests using the little/little method that makes the chain as long as possible and able to handle any 11 speed cassette they sell, with one chain length, including the new 12-29.

As an example, I use a 53 inch length for my frames with 405mm chainstays and a 50/34 crank. If a 53/39 is used, the chain length would be 54 inches.

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