If cycling is to be a comfortable and pleasant experience, the frame needs to be the right size. For children, this is fairly easy; although there are charts that will relate wheel size to rider’s age (so that someone up to the age of four might be recommended a 12 inch wheel and someone between seven and nine a 20 inch wheel), that is less important than following these rules:
- Is the child comfortable on the bike?
- Is the child not too stretched on the bike?
- Can the child turn the handlebars safely as well as operating the brake levers WHILE AT THE SAME TIME keeping the ball of the foot on the floor?
If the answer to all of those questions is yes, child and bike are well matched.
26 inch wheels are considered “adult” (though a typical size chart will also describe them as suitable for children of 11 and up) and then frame size is what counts in choosing the correct bike for the person. On mountain bikes, the rider needs a three inch gap between the top of the frame and the rider. On racing or road bikes, that comes down to 1 inch. So, take the inside leg measurement all the way to the floor and then deduct one inch (or three inches for mountain bikes) and the result is the maximum frame size for that rider.
But that is the maximum and it doesn’t stop there because, the taller the bike, the longer the bike – so someone with a relatively long inside leg measurement and a relatively short torso will need to balance a smaller frame with a longer saddle stem in order to be able to reach the handlebars and operate the controls safely. There is, in other words, no substitute for sitting the rider on the bike and saying, “How does that feel?”