In contrast to the frozen action images, I started panning the subject in order to show motion and speed, but when using a lower shutter speed, unfortunately we then have a small aperture with huge depth of focus… panning hides what would have been an in-focus background, and therefore would be very difficult to separate the subject from the background.

Suzuki – 1/160th Sec f18 ISO200 Focal Length 200mm (Nikon 70-200mm f2.8)
I needed to get the rider in sunlight and chose a position on the outside of the bend… making it more difficult to pan as the subject distance from the camera changes continuously…

No77 – 1/200th Sec f9.0 ISO200 Focal Length 200mm (Nikon 70-200mm f2.8)
Panning alone a straight section may be easier to focus, however it also brings a challenge of higher speeds…