On level ground on my set up if I put it in level 1 re-gen, I would have to pedal hard to ride "normal", in level 2 re-gen I would need to pedal like up a 5-6% hill, On level 3 re-gen I would have to pedal like going up a 12-13% hill, On level 4 re-gen I would have to stand up and pedal to go anywhere... That's how much resistance re-gen can make in rolling resistance on level roads...