For the ribs: Pat ribs dry with paper towels. Rub evenly on both sides with salt and place on wire rack set in rimmed baking sheet. Let stand at room temperature for 1 hour.

For the vinaigrette: Combine oil, garlic, and rosemary in small bowl and microwave until fragrant and just starting to bubble, about 30 seconds. Stir in lemon juice and set aside.

For a charcoal grill: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour evenly over grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.

For a gas grill: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Turn all burners to medium-high.

Clean and oil cooking grate. Brush meat side of ribs with oil and sprinkle with pepper. Place ribs meat side down on grill. Cover and cook until meat side begins to develop spotty browning and light but defined grill marks, 4 to 6 minutes. Flip ribs and cook, covered, until second side is lightly browned, 4 to 6 minutes, moving ribs as needed to ensure even browning. Flip again and cook, covered, until meat side is deeply browned with slight charring and thick ends of ribs register 175 to 185 degrees, 4 to 6 minutes.

Transfer ribs to cutting board and let rest for 10 minutes. Cut ribs between bones and serve, passing vinaigrette separately.