There is no best before date in learning how to ride a bicycle. Anyone can learn, and at any age. Nobody should be afraid to learn, including a little one. Exposing a young child to a bicycle can not only help with exercise, but with mind and body connections.
Our 3 year old, has become obsessed with his push bike. It has no pedals, and you learn quickly how to balance. It is incredible to see how quickly he adapted and has gotten more and more confident with every push.
He has become so fast, that we now how to run beside him, and he can stop pushing and coast for quite a while.