For the ribs: Position an oven rack in the middle of the oven and preheat to 325 degrees F. Line a large baking sheet with aluminum foil.
Remove the silver skin on the backside of the ribs and discard. Place the racks of ribs on the prepared baking sheet, meaty-side up. (If the racks of ribs are too long for your baking sheet, arrange on 2 lined baking sheets, cutting the racks in half as necessary.)
For the dry rub: In a small bowl, mix together the sugar, chili powder, paprika, garlic powder, onion powder, cayenne, cumin, 1 tablespoon salt and 1 teaspoon pepper. Sprinkle the rub generously on top of the ribs, saving just enough for a light rub on the underside. Tightly cover the entire baking sheet with another sheet of foil and bake until the meat falls easily off the bone when you pierce it with a fork, 2 1/2 hours.
For the beer-b-q sauce: Meanwhile combine the ketchup, beer, honey, Worcestershire, sugar, mustard, garlic powder and onion powder in a medium bowl and set aside.
Remove the ribs from the oven and let rest for 15 minutes. Meanwhile, preheat a grill for cooking at medium-high heat. Using a pastry brush, brush a medium layer of beer-b-q sauce on the meaty side of the ribs. Gently place the racks of ribs, meaty-side down, on the grill and cook until there is a nice char on the meat, 5 to 7 minutes. Remove from grill and let rest for another 5 minutes. Slice and serve with your favorite sides!