Mike CT has posted his method for bending GarGraves several times and while it's mostly half circles, the same concept can be used for other size arcs. I don't think he went as tight as O54, but I could be wrong. From what I've read here, the key to bending any O scale flex seems to be to over-bend it so there's less pressure to return to it's original position. My very limited experience playing around with ScaleTrax says bending the final few inches is the pits. Someone suggested bending most of it to the position you want and then cut off the end. I'm sure you'll figure out a way that works for you.
BTW, the bridges were just so you could see the 3D aspect better.
