around 1/30 is definitely where you want to be unless the bike is going so fast. Since this is a set up shot I suggest just ride your bike at like 20mph with 1/30 shutter speed. People wont know how fast you are riding the bike anyway. Set the camera to burst mode, AI focus (Canon term, not sure what Nikon is), and turn on all of your AF points. Then just try to keep the bike in the middle of the frame while shooting (follow the bike while shooting). Just burst your shot so you take 4-5 shots and pray one is good LOL. Here is some of my panning shots.
http://www.thephotoforum.com/forum/...orum-photo-gallery/216765-how-my-panning.html
1/30 came out blurry. It worked great on the cars though. I'm going twice as fast as the cars though. I can't really slow down because I need the speed to get down low (lean) since that was the shot I wanted. I had the camera's focus set to continues servo so that it AF and was using burst mode. Thanks for the tips though. Looks like yours came out great!
Here is what I was going for. This was me at tail of the dragon (North Carolina) taken by professional photographers on the good corners.