Red Kryps in action.
Further to the requests for info I took around 60 shots before I had one without camera shake.
Attached a tripod (closed) to my skateboard via the use of a metal splint which was taped at both ends either side of the board. I then set it to self-timer and [carefully] did some toe-side kickturns on the smoothest part of the road I could find.
Shutter speed was faster than you might imagine - I had a ND filter attached to a Sony F717.
There's no Photoshop blur involved as I'm a bit of a purist!