Prepare a medium-hot banked fire in covered kettle style grill.
Cut each slab of ribs between ribs into four pieces. Place rib-side-down over indirect heat and grill for 1 1/4 hours.
Meanwhile in a saucepan combine catsup, Worcestershire sauce, cherry cola, vinegar, paprika, chili powder, pepper and onion; simmer 10 to 15 minutes, stirring occasionally.
Brush ribs generously with sauce and continue to cook, about 20 to 30 minutes, basting and turning often, until ribs are nicely glazed.