Most kids hit the path by age one. Confirm your child holds their head up...

https://shanestue668.yousher.com/can-i-use-a-child-bike-seat-on-a-mountain-bike

Most kids hit the path by age one. Confirm your child holds their head up strong while wearing a helmet. Pick front mounts for interaction, rear seats for stability, or trailers for naps. Your kid is ready when they sit up firmly on their own.