Start biking once your baby sits well unsupported and holds their head steady...

https://www./parenting/when-can-a-baby-go-in-a-bike-seat-an-age-by-age-guide/

Start biking once your baby sits well unsupported and holds their head steady in a helmet, usually around age one. Choose a front seat for bonding, a rear seat for growth, or a trailer for extra stability. Keep your first rides short and fun.