Hi, I am new to riding and love it. I have a 12-26 9 spd cass but need help up hill. Looking at a new cassette 11-28 9 Saint/SLX HG80 9-speed. Will i need to get a new chain? Also need a new lge chain ring (50) as i a big bloke and bent mine. I ride a cannondale optimo 3 cycle X with a shimano 9 spd chain(only on road as it was a bargain). Need to do it online and get it right. Pse help.