I started by selecting the motorcycle, rider and shadow and moving it all to a new layer. I then needed to fill the hole left from removing the bike and rider in the background. Since I was not only planning on including the parallax effect but also making the whole thing look like the motorcycle was banking through the turn as well, I need to make sure that the background fill looked as realistic as possible. I then turned my attention to the shadow of the motorcyclist- I needed it to be transparent and consistent no matter where it fell against the background to add to the realism. After all of that was done, I set up the overall movement of the background and the rider. Photoshop only has a linear curve progression between key frames so it took a little while of tweaking and the creation of 17 key frames to get the motion right.
It all came together quite well and I am very pleased with the results- it looks like an actual scene from a motorcycle race! Check out the progression of modifications as this project came together.