The picture is from the movie "Yes Man", and they could have used some tips on controlling that scooter. So it brings up another lecture topic.
Countersteering was not well known in motorcycling circles until the late 70's. But the concept is easy to discover without any prior knowledge, and I'm sure many people knew about it before it had a name. I first discovered the concept after a brush with death on one of my first motorcycling trips. I was taking a sharp curve in the road a little too fast, and tried leaning over further in order to avoid drifting into the lane of an oncoming truck. But the further I leaned, the more the bike stood up. I don't know how I missed the truck finally, but the bike eventually leaned over enough to get back into my lane.
I didn't want this to happen again, and tried to find out why the bike didn't want to lean over. This was a very small bike, and I should have been able to easily overpower its tendency to remain upright. And most of the time it darted around in a very nimble way - but just when I got surprised by the corner and the truck, it suddenly stood up and refused to budge. Why?
After a couple of weeks, experimenting while driving, I discovered an interesting phenomenon. If I tried to steer into a corner with the handlebars, instead of leaning, the bike leaned the opposite way. Obviously, when I met that truck, my instinct must have been to steer out of its way, which had the effect of making me go straight into it. Finally I had the answer to my problem. The amount of turning the bars actually did was so small you could detect it as only as a slight pressure on the bars.
But soon I was thinking - if steering into a corner has the opposite effect, what if I deliberately steered away from the corner? It should theoretically make me lean into the corner even quicker. I tried it and found out that this worked quite well. Before I discovered countersteering, I was a bit slow leaning the bike into the corners - partly because the gyroscopic forces on the wheels build up a bit of stability. Counter steering allows the rider to lean the bike over very quickly without waiting for it to "fall" over to the right angle for the corner.
So the correct technique for cornering is to lean the bike to the appropriate angle by counter steering. Then once at the correct angle, maintain the curve by steering through the corner. Adjustments to avoid potholes can be done by pressing on the bars.
When Mary Ann learned to ride the scooter, I tried to explain counter steering without too much success. But one day I was riding on the back without much traffic around and I decided to see how much control she had so I leaned over to one side. It took her a bit of time to lean the opposite way to straighten up the bike - which means she was not aware of counter steering. If you use counter steering, you can compensate instantly for a passenger leaning off to either side unexpectedly. So on the way home I tried another experiment, I grabbed her elbow and pushed it which instantly sent the scooter off on a cockeyed angle. Then I straightened it up with a simple push on the other elbow. Although she was actually quite angry about me fooling around like that. When we stopped she said "You violated the most basic law of being a passenger." "What law is that?" "That you're not supposed to be doing the driving!"
But she did get the idea that pushing on the handlebar (countersteering) has more influence on the lean of the bike than body lean.