The question is... is it normal to feel -1g in a heartline roll? I always find it hard to control g's there while it's pretty easy to reduce lateral g's to a minimum or an acceptable level.
Like dcs already said. If the heartline roll is just a straight roll with no curvature. You'll be experiencing about -1g during the roll. This would be the hangtime you're experiencing when upside down.
Coastercount: 1410(I've seen the world and it's horrid contraptions... @.@) - Wood: 142 - Steel: 1268