Step 1Combine vinegar, honey, ketchup, oil, garlic, rosemary, sage and pepper flakes in food processor or blender. You will have about 2 cups. Place chicken in resealable plastic food bag and pour 1 cup over chicken. Through plastic bag, work marinade around chicken. Seal bag and place in shallow pan. Refrigerate overnight, turning bag occasionally.
Step 2Simmer remaining 1 cup sauce in small saucepan, uncovered, 5 minutes. Strain, discarding solids. (Can be refrigerated up to 1 week. Reheat before serving.)
Step 3Prepare grill for indirect grilling. When hot, toss half of chips on each pile of coals, if using charcoal. For gas, put chips in smoker box.
Step 4Transfer chicken from marinade to pan; reserve marinade. Season chicken with salt and pepper. Grill chicken over indirect heat, turning after 30 minutes and brushing often with reserved marinade (use it all), until fully cooked and bronzed, about 60 to 70 minutes. Internal temperature (taken in thickest part of thigh) should be at least 165 degrees. Pass warm barbecue sauce separately.