[bht]

Novice question:

I live in an area that requires a significant amount of climbing. I was considering changing my casette from a 12-25 to a 12-27. I have 9-speed Ultegra.

Is this a worthy change, and are there any downsides? I would prefer to do this rather than change to a compact, triple, etc...

Thanks in advance for any help.

 

[ericm979]

It's a fine change. If your chain is very short then it may be too short with the 27t. When you fit the new cluster, check on the workstand that the bike will shift into the 53x27. You should not use that cross-chain combination but your bike should allow you to shift into it in case you make a mistake when you are tired.
The only drawback to the 12-27 vs the 12-25 is the larger gap between the last two cogs.

 

[JayTee]

Don't bother until you need a new cassette. It isn't worth the dough straight up. It's only one more cog. Wait until cassette replacement time.

 

[chang100]

Ditto that

I recently replaced my 12-27 with a 12-25, since the shop was out of stock on the larger cassette. I haven't noticed any significant difference in effort, and I ride a lot of hills. It was nice having the 27 as a security blanket, but chances are you won't use it too frequently. Just wait until the old one wears out and then get the 12-27.

 

[funknuggets]

For what its worth, I agree as well, its not worth the $$$ to get to a 27. Don't give up, I would say that technique, experience and weight loss (either you or on your bike) would probably do more to help you than getting a 27. Im sure that someone will be able to tell you the specifics on how "easier" it would be, but I would say if a 39x25 is hard for you, a 39x27 will be too.

I have three, one 11-21, 11-23 and 12-27.

 

[BarryG]

Is this a worthy change?

yes, this is a worthy change