Graves Yamaha’s Hacking heads up Repsol Superstock coming into Barber. Pickerington, Ohio (April 19, 2006) The AMA Lockhart-Phillips USA Formula Xtreme Series has been the domain of factory Honda rider Miguel Duhamel over the last couple of years, but now that the two-time champ has moved on to concentrate on AMA Superbike it leaves the class wide open. Honda has dominated Formula Xtreme and hopes to keep that going with Erion Honda riders Josh Hayes and Aaron Gobert, but Yamaha has thrown its hat in the ring with a potent pair of riders in Jason DiSalvo and Eric Bostrom. This weekend, April 21-23, at Barber Motorsports Park in Birmingham, Ala. the battle for the championship gets back underway after an early season break.