In reply to beneboy: In reply to beneboy: Nice work Ben, really think we should get a shoot together this summer.
In terms of the shots, I appreciate the stylised effect but a closer balance bewteeen flash and ambient would bring some more detail into the shadows you mention. Up the ISO, down the flash power. (Increased aperture would have same effect but can make focus tracking a bit more hit and miss with the reduced DoF.) Does mean you have to be a bit more accurate with your panning technique though, but you only really need a small amount of panning blur to convey the sense of speed, so at that close range maybe a 60th would work. So at the other end of the 'strobe lit panning shot' scale you'd have an effect like the second shot in this gallery:
http://nelsonimages.co.uk/galleries/3_Mountain_Biking_Downhillv3/
Just a matter of playing with the set-up till you find what you like.
Personally I like what you've done already.