Memphis Style Dry Rub Spare or Back Ribs

1 cup brown sugar
1/2 cup paprika
2 1/2 Tbsp fresh ground pepper
2 1/2 Tbsp salt
1 1/2 tsp chili powder
1 1/2 Tbsp garlic powder
1 1/2 Tbsp onion powder
1 tsp cayenne pepper
2 large racks baby back ribs