Here's a bike story (actually more than one). DEFINITELY NOT AGAINST A PIT BULL . . . but . . .
I used to train out in farm land and the dogs often would come running across a field and give chase. I was super fit ON A BIKE and I could out run them. So I have ben chased a lot by medium sized dogs.
In the city, commuting to work, I have had a few goof balls that think the street is their turf and get all bity and stupid on a repetitive basis. For them I have a special service . . . I wheel around and with single mindedness to get my hands on their throat I CHASE THEM !
To a man they totally fall apart and run for their life. I once chased one across a yard, threw the bike down, into an apartment building ( the door was propped open ) and up three flights of stairs until I cornered the poor sucker cowering and trying to hide under it's self. I've chased them back into their yard around their house ( no fence ) and down the street for a block still on the bike.
Only after repeated "attacks".
Funny as hell.
Probably not the best Idea. But I enjoy it.