I've got an Allez Sport 2014 edition which is fitted with a SORA 9 speed groupset. The rear cassette is an HG-50, 9-speed, 12-27T. I'm looking at purchasing an 11-30T version of the 9 speed HG-50 to get up some sharp hills which are, at times, ruining my fun on rides.
Firstly, could someone...