Originally Posted by
Retro Grouch
The important thing that nobody has mentioned yet is chain length. A bigger cassette will need a new, longer chain.
It's important to have a chain that's long enough to safely cover your big/big combination. If your chain is too short, and you ever accidentally shift into that combination, it can cause a BUNCH of damage in less time than it took me to type this sentence.
I did not think of the chain length issue, thanks for mentioning it. I am in a habit of not using the upper half of my cassette when in the big ring up front, and would for sure not cross gear big/big rings.
Would I have to get a new chain if I just went to 28T?