Joe, 11.25" is pretty sharp - toy train territory. There was a design decision along the way, "do we want a toy, or a model?" Sharp curves with an 8-driver steam locomotive would mean a serious, serious compromise in model fidelity to be able to negotiate the sharpest curves. The J is best on 15" minimum radius. While I feel for you with your disappointment, there has to be a little bit of expectation management on your end: you can't have it both ways - accurate model running on curve radii that are impossible "in nature".
Yes, you do need to research easements. Easements are how the real thing handles transitions from straight ("tangent") track to curves - the operative word being "transition". This can be approximated by using a section of larger radius - 19", for example - between the straight section and your smaller curve. It will significantly reduce the tendency for the J to climb the rails.
This is all the crux of my particular beef with Bachmann, the older DDA40X models - they compromised the model design to allow the tower-type drive mechanism to handle 9.75" curves. As a result, the model is nearly 2 scale feet (20%) too wide, which completely buggers the proportions. Model fidelity goes out the window, reducing them to toys. I'm gritting my teeth in hopes that the new version fixes this.
Yes, you do need to research easements. Easements are how the real thing handles transitions from straight ("tangent") track to curves - the operative word being "transition". This can be approximated by using a section of larger radius - 19", for example - between the straight section and your smaller curve. It will significantly reduce the tendency for the J to climb the rails.
This is all the crux of my particular beef with Bachmann, the older DDA40X models - they compromised the model design to allow the tower-type drive mechanism to handle 9.75" curves. As a result, the model is nearly 2 scale feet (20%) too wide, which completely buggers the proportions. Model fidelity goes out the window, reducing them to toys. I'm gritting my teeth in hopes that the new version fixes this.