When can a baby ride a bike?

I was asked recently how old a baby should be before riding in a bike trailer. I’ve been meaning to compile what I read about it before we shopped for our bike, so here you are!

First, bike trailer manufacturers say to wait until the baby is a year old. I found that our babies didn’t fit well in the trailer until then anyway (and we still put a pillow in behind them, even now at almost two).

Our bike seats are designed for children nine months and up. They are far more supportive than the seat in the trailer, and sized for a baby, so they work much better for the under-ones. But they are Dutch seats, designed for cycling in the Netherlands, where nobody wears helmets.

When thinking about biking with children, the first risks you may think are the risks of falling or of getting hit by a car, but for a baby, another worrying risk is shaking. Babies have heavy heads relative to their neck strength and helmets make that worse. Trailers are bumpier than you think. On our bike, the front seat is more stable than the rear.

So when can you ride with your baby? It depends on why you want to ride with your baby. There is no reason to put a baby on a bike before a year for recreational riding. You can go for a walk. For transportation cycling, there are benefits to mitigate the risks. There are benefits to the family, the child, and to society. Riding in a car is not risk-free, even if we think of it that way. It’s not just the immediate risk of collisions, but the more pernicious long-term risks of a car-dependent society that concern me.

Here are more articles for you to read.

How they do it in the Netherlands

A nice article about different options at different ages

A long discussion about biking with infants (in the comments)

More on equipment options and risks

I hesitate to post this article, because it’s alarmist, but you may need to counter these arguments if you choose to bike with your baby.
In addition to the above, here are some people who have biked with really small babies.

Note: I am not a doctor, nor any other kind of professional that might help you make this decision.