How old should your child be when they can start safely riding? There are too many variables to say for certain, including most importantly, your child's own agility and ambition to ride. The second most important issues to consider is your own judgement as to when you think the child will be responsible and safe enough to ride. You'll know if your child is ready.

When my eldest son was two he got his first electric quad. I knew he would be safe on it because before he got that, he had a Big-Wheel which he promptly rode out the back door, down two steps and over the bars. He knew where he was going, I'm sure of it. After a very brief cry he got right back on it and rode it straight out the back door again, and made it to the grass.