Sigma-galant.com

This is by far the best video explanation of how a differential actually works.
Give it a couple of minutes to get into it, and the Motor bikes do have a part in it, so dont necessarily skip through.
But if you really have to, skip to 1:50min

Cheers

http://www.youtube.com/watch?v=yYAw79386WI

That is an awesome video, thanks for that Dan. Definately worth watching

nice video man

nice one.