Anyone can answer . What do you think of drivers leaning back in the gig?
IMO leaning back in the the gig gives no more of an advantage than sitting up straight with your weight balanced over the axel. In fact weight behind the the axel can cause a wobble action even if unseen. This is demonstrated by people towing caravans with more weight behind the axles. They are called "wobblers" .Watch a movie called " The Worlds Fastest Indian "