I finally was able to take my Trek Crockett 5 into the woods for some trail riding. It was pretty fun but was noticed the hills were a bit of a hassle. I don't want to change the front so is it possible to go to a different cassette. It has a 12-30 now, would going to a 12-34 or lower work with the rear derailleur? I need to build my fitness back up, but I don't think this will affect the main reason I have the bike which is gravel and crappy days.