Was wondering where you'd went Ewan, it's been a while since I've seen a post from you :P

Nice looking little kilobot there! That's probably one of just a few properly active ones around just now, most of the designs people have been discussing haven't yet fully materialised, mine included.

Those are the Lego Technic tracks aren't they? Just curious what you're using for rollers/hubs/whatever-you-want-to-call-them in place of the plasticy yellow rollers that are part of the Technic track kits, as I was contemplating making a tracked kilobot out of them but deemed the yellow bits too much of a weak spot for being brittle/not very robust.
In fact, a general parts breakdown would be cool if that's okay? Motors, controller etc?