Comment by culebron21

I think the reason you easily learn on this type is that you have much more practice in the same piece of time. On normal bike an error leads to falling, having to restart, which takes half a minute at best. On running bike, you don't fall and continue. Each iteration takes 1-2 seconds.

My 3yo rides this 'running bike' as it's called here, no prob. My training in childhood, on normal one with pedals, was a nightmare.

Earlier I thought of the way to transition from 'running bike' to normal pedal bike, and thought of teaching first to ride while standing on pedals, and only then to sit down. Another comment here, about 'women bikes', confirms this idea.