A baby bike seat becomes an option once your child can sit up unaided and steadily, and weighs at least 9 kg. They must wear a helmet that fits, which is compulsory under 12, and the seat must be approved to the European standard EN 14344. The rest of the choice depends on age, the bike and your journeys.
This guide brings together the rules set by the French Highway Code (Code de la route) and the advice published by the Institut national de la consommation (the French national consumer institute) with Unaf. It will help you decide between a front and a rear seat, check the safety points and prepare for your first rides.
Baby bike seat: from what age?
No regulation sets an age in months. The benchmark used by the Institut national de la consommation is functional: the child must be “old enough to sit up”. A baby who still slumps to one side or tires quickly when sitting is not ready.
This milestone varies a great deal from one child to another. Our article on the age at which babies sit up on their own covers the stages and the signs that show the trunk is strong enough. On a bike, you add vibrations, braking and the weight of the helmet on the head: it is better to wait a few more weeks than to start too early.
Weight gives a second benchmark. Compliant seats take a child from 9 kg minimum to 22 kg maximum. Below 9 kg, the harness and footrests do not hold the child properly.
What the law says about carrying a child by bike
Two obligations apply in France. The first concerns the seat: a child under 5 carried on a bike must sit in an approved seat. This seat is marked with the European standard EN 14344.
The second concerns the helmet. Since decree no. 2016-1800 of 21 December 2016, which came into force on 22 March 2017, wearing a helmet has been compulsory for children under 12, whether riding or as passengers. An adult carrying a child without a helmet faces a fourth-class fine, i.e. 90 euros.
Finally, outside built-up areas, at night or in poor visibility, the rider must wear a high-visibility vest. This rule applies to you, even if your child is sitting behind.
Front or rear seat: how to choose?
The two formats suit different ages and uses. The Institut national de la consommation sums up the rule like this: at the front for the youngest, at the rear for older children.
The front seat
- It attaches to the frame tube or the stem, between the handlebars and the adult.
- Your child can see the road and stays within earshot, which often reassures the little ones.
- It generally takes a lower maximum weight than a rear seat: check the limit in the instructions.
- It can get in the way of the rider's knees on a small frame: try it before you buy.
The rear seat
- It attaches to the pannier rack or the frame, depending on the model.
- Compliant models are suitable up to 22 kg, so it lasts longer.
- It often has a higher backrest and a reclining position for naps.
- It shifts the weight to the back: the bike feels lighter at the front when you set off.
For a first seat around the first birthday, the front seat wins on closeness. For daily use over several years, the rear seat lasts longer. Some families start with one and then switch to the other.
Safety criteria to check in the shop
Beyond the standard, a few details make all the difference day to day. Take the time to handle the seat and, if possible, to sit your child in it.
- The harness: it must be sturdy and hold your child without squeezing. A buckle your child cannot open alone is preferable.
- The footrests: height-adjustable and fitted with side guards, they stop feet from getting caught in the spokes.
- The foot straps: feet must be properly strapped in, especially when your child falls asleep.
- The backrest and headrest: they must leave room for the helmet without pushing the head forward.
- The mounting: it must be stable and compatible with your frame and pannier rack.
- The bike's load capacity: check that the bike and the pannier rack can take the total weight, child and seat included.
Which helmet for a baby on a bike?
Choose the helmet by head circumference, not by age. It must stay put when your child shakes their head, with the chin strap adjusted under the chin. A helmet that is too big protects poorly and slips over the eyes.
On a seat with a high backrest, a helmet with a flat back stops the head being pushed forward. Always take the helmet off once you arrive, before letting your child play, for example at a playground: the straps can get caught.
Fitting the seat properly and preparing your first rides
A badly fitted seat cancels out the qualities of the best model. Follow the instructions step by step, then regularly check that the fixings are tight, especially after a knock or after transporting the bike.
- Do a test ride with the seat empty, then with a weighted bag, to feel how the bike handles.
- Put your child in with the bike stationary and on its stand, or held by a second adult.
- Start with short journeys on quiet roads or cycle paths.
- Avoid rush hour and cobbled streets, which tire your child.
- Bring something to cover them: sitting still, they get cold much faster than you.
This last point matters from October to March. Our tips on dressing your baby when it is cold fully apply on a bike, where the wind makes it feel even colder.
Bike seat, trailer or public transport?
The seat is not the only solution. A child trailer protects from the rain and sometimes allows you to carry a younger child, with a suitable baby hammock; the minimum age is then set by the manufacturer's instructions. A cargo bike suits families who ride a lot with two children.
For long journeys or in bad weather, other options remain relevant. Our guide to public transport with a baby and the one on the long car journey round out this choice. In the car, a car seat suited to their age remains essential.
Should you buy a second-hand bike seat?
A second-hand seat can be fine if it is recent, complete and comes with its instructions. Check for the EN 14344 marking and the condition of the plastic, the harness and the fixings. Rule out any seat that has been dropped or has a missing part.
The helmet, on the other hand, is best bought new: an old impact may have weakened the shell without leaving any visible mark. For any questions about our products, our FAQ is here to help.
Sources
- Institut national de la consommation and Unaf, “Comment transporter mon enfant à vélo en toute sécurité ?”, published on 10 December 2025, updated on 29 December 2025.
- Préfecture de Lot-et-Garonne, press release “Port du casque à vélo obligatoire pour les enfants de moins de 12 ans”, 22 December 2016 (decree no. 2016-1800).
