Mix the rub ingredients together in a small bowl using fingertips. Whisk together the mop ingredients into a medium bowl.
Section the ribs: separate the flap and rib tips (separated by a line of fat). De-membrane ribs. Halve any full racks.
Grill over indirect low heat for an hour beore mopping and basting every 30 minutes or so until the meat is tender: 2 1/2 to 3 hours total.
Transfer ribs to a baking sheet and cover in foil to let rest 30 minutes before serving.