Children's bikes are generally measured by wheel size, rather than by frame size. Remember children do grow very quickly and you need to take this into consideration when buying a kids bike, However, if you buy a bike that is simply too big for your child, you will compromise your child's safety, and ultimately discourage your child from cycling.
Age of Child
Which Size Bike Do I Require?
Adults bikes and those for 10/11 years and over, are generally measured by frame size. This is normally the measurement between the centre of the bottom bracket to the top of the seat tube.
This Ok Baby Sirius Frame Fit Child Seat - 2 Colourscontains the following features as listed below:
Child weight MAX: 22 kg
To be fixed on the seat tube with diameter between 28 and 40 mm
Adjusts horizontally by changing the angle of the multi-position backrest
Reclining backrest (30°)
Folding bike seat easy to carry and to store away
Equipped with ABS (Automatic Barycenter System), which maintains the center of gravity in the right position regardless of the seat back angle
Footrests: height adjustment in thirteen positions and equipped with safety straps and protective guards to avoid contact with the wheel spokes
3-point safety harness adjustable in height in two positions and in length
Approved rear reflector, to make the bike seat more visible on the road
Thermoformed, water-repellent and weatherproof padding
The padding can be hand washed in lukewarm water with neutral soap
Equipped with combination lock security system bracket
Patented model: you can recline the bike seat without compromising the balance, because the center of gravity stays in place over the center of the wheel. You can recline the bike seat with the child on it, while riding your bike, thanks to a central push-button.
The seat can be also mounted on power-assisted bicycles (E-bikes)
Supporting system that dampens vibrations caused by the unevenness of the road