New to the site. Just purchased Giant roam 3 yesterday. Love so far. I got this knowing it didnt have disc brakes, but could upgrade to them. I purchased it on sale for $385 giving me flexibility to do so. I just so happened to get a amazon gift card for xmas and i dont shop on amazon. I want to use this card to upgrade the rear brakes to hydraulic disc. The same brake is on amazon for less than $100 that are used in the roam 1. Has any body does this transformation, and could I do it myself? Would the cables fit b/c it is not bike specific on amazon. Is it a fairly easy thing to do? Should I buy and have LBS install. Thanks for your help.