[ncmncm]

I have found I can teach kids to ride a bike in (literally) seconds, just by not lying to them about how it works.

"Use the handlebars to stay up. Lean to turn." Just like that, and they're off. (I am absolutely not exaggerating.)

(And, no, gyroscope effect has nothing to do with it.)

They get the idea to twitch the handlebars the opposite way, to lean, all by themselves. Most never notice they are doing it.

[wruza]

That’s because leaning is such a bad term to describe what happens! Even when I learned to ride bikes, it felt so strange that “you have to lean left/right”, cause I understood somehow that I’m a much more massive object and the center of masses is around my butt at best. So leaning doesn’t change much in mass/geometry/momentum configuration. You may shift a bike under you with your arms, but this is limited to their lengths.

What really happens is that you always fall either to the left or to the right. If you fall in a desired turn direction, you turn a little. If not, you turn even more than is required to support a normal turn, so that your bike moves below you to the point that now your mass part is to the other side of it, and now you fall in the other, initially desired direction. Then you quickly turn at where you need. With practice all this movement reduces to centimeters and very smooth curves at all joints.

You move and (importantly) rotate your bike under yourself. It has nothing to do with leaning, because it’s the road/front tire that make a difference in a balance, not your flanks. Leaning helps to not fall off the seat when you cycle, but not in turns.

It’s clearly a trainer’s delusion to me (that thing when your trainer explains things that do not actually work/exist but you translate or ignore these terms showing respect to a good man).

[ncmncm]

Yet, in fact you and the bicycle are physically leaning throughout any turn. I.e., you are at an angle off vertical with your center of mass distinctly not directly above the line between the points where the tires contact the ground.

Normally the plane of the bike, normal to the axles, cuts right through your center of mass.

Starting a turn by leaning is not usual for experienced bikers, but certainly works. For a beginner, staying upright while going more or less straight is what they need to work out first, but that invariably involves some spontaneous turns, so both are practiced.

What a century of children have been told is to steer with the handlebars, which is a reliable recipe for spills.