Only got to have enough power to overcome friction up! Having said that, many are surprised how quick and “nimble” the ultra’s are through the twisties. The foot boards prevent me from dragging my knee when I ride.
Same with the Street Glide Steelo. I am surprised how well such a big and heavy bike corners. Took it inland from Lorne on Deans Marsh/Lorne road through some very decent twisties the other day and had a fair crack at them. Surprised how it went through the bends! I couldn't get the fat boy to behave that well through the corners. Maybe because of that big wide rear tyre.