A guide to child bike seats
Rear seats come in three basic designs: cantilevered from the seat tube; fixed to a rear carrier rack; and fixed directly to the seat tube and seat stays. Those that bolt to the frame – or to a rack that’s bolted to the frame – are more stable and sturdy but cannot be fitted to bikes with rear suspension.
Cantilevered seats use a big plastic bracket with two holes in it bolted to the seat tube. Into this slots a two-pronged rack that supports the seat. There’s some give in the rack, which offers a degree of springy suspension. This may not flex enough under smaller children, leaving them tipped slightly forwards.
Larger children and/or long-term use may flex it too far, bending it down towards the rear tyre or mudguard. Typically the more you pay, the sturdier the seat will be. The Hamax Sleepy and the Hamax Siesta are some of the better examples. They have a decent attachment bracket and the seat can be reclined.
Seats that fix to a rear carrier rack slide and lock onto the rack’s top, with a safety strap around the seat-post or seat-tube for added security. With the seat off, the rack can be used to carry panniers. The Copilot Limo is the best of these designs and has for some years set the standard in child seats.
The Limo reclines to give a better ride to a sleeping child. Its harness is supplemented by a pivoting grab-bar, like the safety bar on a roller-coaster carriage. What’s more, you can rotate this bar over the back of the seat to turn it into a baby chair when it’s off the bike – so you don’t need to wake your sleeping tot at journey’s end.
Seats that fix directly to the seat stays and seat tube have long legs that bolt to the seat stays, often using a quick-release, plus a bracket that fits on the seat tube to prevent fore and aft movement. The Bobike Maxi is a good one. It’s well made, with a maximum load of 25kg. That should be enough for a six-year-old child, assuming you can still balance the bike properly.
Most seats fit best on medium or larger sized bikes with a conventional top tube. Small frames and those with a dropped top tube can cause fitting difficulties for any seat that uses a seat tube bracket. Open frames – that is, frames without a top tube – can flex and shimmy alarmingly when you’re cycling with a heavier child on a rear seat, because the structure isn’t stiff enough. Look for fatter frame tubes and/or reinforcing tubes if you want to fit this kind of bike with a child seat.