Should be a relatively easy answer, I'm sorry as I'm a newbie. 2011 Trek 1.2 C with a 50/34 crank and 11-26 cassette. I needed a little better ration for steep sustained climbing so I ordered a 11-30. I've heard this may need a new RD and chain. Is there any info I could provide you guys with that would help me determine that, or is there a chance of a straight swap if I stay away from the 50/30 combo.