Thanks for the help folks. If I were to swap the cassette then would the medium cage 105 derailleur still work with a 12-27 or would I have to get a short cage?
The medium cage mech will work perfectly. You might need to shorten the chain a tad for it to be optimum but if you were going to switch back to a 32 large sprocket at any point you could just leave it.
The medium cage mech will work perfectly. You might need to shorten the chain a tad for it to be optimum but if you were going to switch back to a 32 large sprocket at any point you could just leave it.