The sight of mum or dad biking to work with junior on the back is common, and we've come a long way from the time when our own mums gave us a "backie" to school. Now, by law, your bike must be properly equipped if carrying a child, and there is a recommended age restriction of between one and six years – but you can have some fun doing it.

Seats are made of plastic and lightweight aluminium. Front-mounted child seats have a limit of 15kg, rear-mounted 20-25kg. So you can carry more toddler on a rear seat, but you won't also be able to carry a backpack or pannier. High seatbacks prevent neck strain en route; some recline: luxury! With a front seat you can at least see and talk to your child. Counterintuitively, there's little evidence they are more dangerous than back seats – or, indeed, a car. A main disadvantage of top-tube mounted seats is the ungainly knees-out peddling. An advantage of seats is that they're lightweight and cheap, and there are straps and footrests to keep errant limbs from straying. Seats in general offer less tip-over protection than trailers, though some have roll cages.

Trailers are attached to the rear of your bike – junior sits in a hammock seat within. A trailer vibrates less than a seat and some even have suspension. A trailer can carry more than one child, plus toys, which may make for a quieter journey. Some double up as a stroller or luggage compartment and, of course, a trailer has the advantage of being warm and dry and more stable than a seat. A disadvantage is that it's difficult to talk to your passenger, and trailers sometimes have trouble squeezing through some barriers.

Cargo bikes are like a trailer, but the business end is in front, like a massive basket. One make is the bakfiet – Dutch for box bike. Eight feet long and two feet wide, these are the removal vans of bicycles. They're heavy, difficult to steer at first, and as aerodynamic as any other box. But they're ideal for big families, carting up to four kids.

By the age of four, the kids will, hopefully, be thinking outside of the box and on to a tag-along, or trailerbike. This looks like a cannibalised kids' bike, minus front wheel, easily attached by a strong frame extension to the back of an adult's seatpost. There are pedals, too, so it feels like a real bike. By age six or seven, they're ready for their own bicycle, and you'll be free again!