In a bowl, mix cola, ketchup, thyme, Worcestershire sauce, chilli pepper, garlic, salt and pepper to make a marinade. Place the ribs in a large flat container and pour the marinade over them. Cover and refrigerate for at least 12 hours, turning the ribs several times.
Preheat the oven to 180 °C (350 °F). Drain the ribs and place them on a wire rack with a drip pan underneath. Bake for roughly 90 minutes, turning once halfway through, until the internal temperature reaches 63 °C (145 °F).
Pour the drained marinade into a saucepan, bring to a boil over medium-high heat, then reduce to low and simmer for 15 minutes, stirring. Serve the ribs with this sauce, accompanied by baked potatoes and salad.