Comment by TremendousJudge

Sheldon Brown wrote about this years ago: https://www.sheldonbrown.com/teachride.html

> The ideal bike for learning to ride, whether for a child or a deprived adult, is a bike that is "too small" for efficient riding. For learning purposes, the rider should be able to sit on the saddle with both feet flat on the ground and the knees slightly bent. The bike can then be used as a hobby horse or scooter, with the feet always ready to stop a fall. It may even be useful to remove the pedals at first, so that the feet can swing freely. (In case you are new to all this and haven't read the pages about pedals on this site: the left pedal unscrews clockwise!) Ideally, a bike for this approach should have at least one handbrake, so that the child can stop while using both feet for balance. A good place to practice is on a grassy field, perhaps with a slight downgrade.

> Unfortunately, it is often difficult for parents to justify the expense of a smaller bike that will be outgrown shortly, so there is a constant temptation to buy a bike that is a bit too large on the theory that the child will "grow into" it.