Originally Posted by
RexRobinson
I'm' not sure if Disc breaks require a "special frame" for them to fit or could they simply be installed on any bike.
I have the 2016 Allant 7.2, which is the same as FX 7.2 but with mechanical disc brakes. The frame and fork have mounts for disc brakes and there's no mount posts for V-brakes. You can't switch an Allant from disc to V, or an FX from V to disc (without doing something to the frame/fork). You can change or upgrade the Allant to different disc brakes, of course.
Some of the Surly frames, e.g. Troll, are compatible with both discs and rim brakes.