they are barred; Barring is sex linked which is why so many autosexing breeds use it (legBAR, welBAR, and so on).
What you get in a cross, depends on what you cross it to, and if your legbar is the roo or the hen. What hen breeds do you have to cross your roo to? Have you tried playing with the online 'chicken calculator' to get some idea of the cross results posssible?
What is your aim for crossing? Just curiousity? To get sexable chicks? To get some pretty looking chickens (for the last, I'd go for a crele look, which is basically barred, but more colour/red rather than just black/white)