Moving from a bigger rear cassette to a smaller one

[lonetoe]

Sorry for the stupid question:

If I am moving from a 12-27 rear cassette to a 12-25 rear cassette, I don't need to change the length of the chain, correct? Reason being that if the derailleur can handle the 27, it can certainly handle the 25, and since the small cog (12) hasn't changed, I don't need to shorten the chain. Your help is most appreciated.

 

[dabac]

Correct.
No issues with bigger-to- smaller cassette.
Your new biggest sprocket will be like your old 2nd biggest.
Not a problem.

 

[lonetoe]

great! thanks very much