Originally Posted by
Princess_Allez
The drivetrain is all fairly new. It has ~1500 miles on it. It's all the factory stuff that came on my 2018 Specialized Allez Sprint.
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
I wore out a chain in about 1500 miles a few years ago. Chains are cheap enough that it's a no-brainer to get a new one when you buy a different cassette. You could always put the old one in a baggie and save it in case you ever want to put the old cassette back on.