I'll have to pull out my tattered copy of 'Curious George Rides a Bike' to confirm, but I'm pretty sure he also stood on the handlebars and did the no-hands thing.
When I was a kid, Evil Knievel was our 2-wheeled hero, not Curious George. I managed to survive all kinds of stunts on my banana seat bike without a helmet, even the things George is guilty of, and I survived. Of course, my mom wasn't watching or I wouldn't have been able to do half the stuff I did...
But, if you decide to boycott everything related to the little monkey or the Man in the Yellow Hat, I got dibs on your old Curious George lunch box.
James