Anybody know of any good cross trails?
do you mean cyclocross and exactly where are you talking by Sydney (North), its a big place?
Yes, I do mean cyclocross. Anywhere this side of the bridge, maybe within about 25kms or so.
CX Winter Series
the only ones I know of and that's only because I have a mate that races them. The course is not laid out when there is no race on and shares equestrian facilities but I think you can ride most of it most of the time.