Originally Posted by John V Strom, Jr.
Here's the difference: If you could lock your fork so your front wheel directly aligns with the rear and you do your "hands free" ride, your going to find the bike won't change direction no matter what you do.
Leaning, shifting weight, etc. can change the angle of the wheel's direction with no handlebar input, but then the bike falls into it's own lean opposite the direction of the tire, as Spec says. You have initiated the bike into a counter steer, just as if you'd moved the bars. The machine always turns by counter steering, as it cannot change direction by any other means. The physics follow its design.
Discussion of counter steer always gets overly complicated, but it's best to think of counter steering as a definition of how two-wheeled vehicles turn rather than what riders do on a bike. Simply put, if you ride a motorcycle or bicycle, you, the bike, are counter steering.
Of course if you lock the fork straight ahead the bike will go straight. That does not mean weight changes and countersteer are the same thing. Countersteer is pressure applied to the handlebars to steer them toward the outside of the turn, forcing a lean. Weight shifting without touching the bar is not countersteering. You are simply changing definitions or employing tautology.
If I hit an object in the road, it also can turn my bike. But I call that deflection, not countersteer. Countersteer is force input via the handlebars. Weight transfer or deflection may move the front wheel off the centerline, but I don't think that is countersteering.
Each technique is to get the bike leaned so the wheel rotation gyroscopic action, combined with the tire's rounded profile, makes the bike follow a curved path.
These aren't great videos, and the second is better than the first, but they do show you can negotiate curves without touching the bars.
There are situations where weight transfer instead of countersteer is the better way to change direction. Like if you get right on the edge of the pavement where there is a dropoff, I find weight transfer can bring you back from that edge, but countersteer can take you over it.
Similarly, sometimes you should lean your body to the inside of the curve, and sometimes you should lean your body to the outside of the curve. There are lots of different tools to use.
I don't have any interest in convincing anybody of anything. If you want to believe countersteer is the only way to make a bike turn, that's fine with me. But nobody will convince me something is impossible when I have been doing it for over half a century, not even Keith Code.