Rub ribs with oil. In a small bowl, combine the brown sugar, paprika, pepper, onion powder, garlic powder and cayenne; rub over ribs. Wrap in a large piece of heavy-duty foil (about 28 in. x 18 in.). Seal the edges of foil. In a small bowl, combine barbecue sauce and beer; set aside.
Prepare grill for indirect heat. Grill ribs, covered, over indirect medium heat for 1 hour. Carefully remove ribs from foil. Place over direct heat; baste with sauce mixture. Grill 20 minutes or until meat is tender, turning and basting occasionally with sauce.