It helps to know *just* where to push an oncoming bike without damaging yourself. I've only done that once - walking down the pedestrianised area of town some years back and a bunch of chavs were generally being idiots (as per). I had a pop at one of them because they were behaving properly anti-socially, and shouldn't even have been riding as it was quite busy. Anyhoo, after about 5 minutes they came back the other way, so I stood right in front of the lead chav, ducked out of the way at the last second and gently tagged the end of his left bar as he sailed past. Nothing quite as satisfying as a crumpled heap of whimpering Adidas
They all got off and walked