Experts agree that infants younger than one year should not ride on bicycles, and some states even prohibit it. This has nothing to do with parents’ biking ability, but is simply a reflection of a baby’s development.
They’ve only begun to sit securely on their own at nine months. Pediatricians point out that while infants are still developing bones and muscles to sit up straight, they likely would be sitting in a slumped position in a bike seat or trailer. This would only be made worse with the weight of a bike helmet. In addition, their necks may not yet be strong enough to withstand the activity.
When your child is ready, parents should consider their biking ability in choosing a seat style to avoid a bike crash. The type of bike seat where the baby sits high and behind the rider makes the child more visible to cars, but the bike is harder to maneuver for the parent. Trailer carriers that run behind the bike on their own wheels are easier to maneuver for inexperienced cyclists, but harder for cars to see.