I rode on the back of my dad's bike back as far as I can remember so did my brother. I have pictures from before I was 5 and we never had a problem. I can tell you we never had properly fitting helmets or gear. Fast forward 20 years as I was coming down the street with my oldest son on the back of my CBR the middle son runs out in front of the bike, clips the bar end, bike flips both me and son land high side style on our head and right shoulder. Broken collar bones for both of us, luckily we had Helmets. Then when we healed up we went riding again. I also continued to ride my Daughter who was 7 years younger than the boys. I also never let any one else's kid ride with me. Even relatives kids.
Because this can happen! St patricks day this year in Kansas City Mo,