yep, as brandoz said, in the motocross world they are called whoops but have a million different names. on a side note, damn those guys are good, and that track looks amazing
Whoops. The reason you want a good a-arm and shock set up, 4+1 rims and no spacers. I love a nice rhythm/whoop section.... but if your bikes not set up for it, you get beat to hell.