Most experts recommend waiting until your baby reaches the 9 to 12-month mark...
https://wiki-planet.win/index.php/What_should_a_baby_wear_in_a_bike_seat_in_cold_weather%3F
Most experts recommend waiting until your baby reaches the 9 to 12-month mark before riding. Your little one needs rock-solid neck and core strength to hold their head up comfortably while wearing a helmet