At left, Maiky Cabrero of San Sebastián By THE STAR STAFF Riders from the Dominican Republic will compete against their Puerto Rican counterparts in the extreme sport of motocross on Sunday, Aug. 2 at the “Rush Motocross & Off Road Park” in Vega Baja, an event expected to draw extreme sports enthusiasts in large numbers. “This sport has a fanbase that thrives on the adrenaline and euphoria of these engines, and this time our national riders will be facing off against our Domi