Bluebottle, I like your explanation. It is rather elegant.....
Thanks Liamjs, I have an unfair advantage as I get paid to know about dynamics (but get abuse for giving the same info for free - what a weird world)
You are correct about speed being key to handling differences between a pedal and motorcycle ( also geometry and tyre cross section).
Don't worry about whether counter steer or weight transfer cause the turn - it is more that they enable the turn because they initiate a lean.
A turn without a lean is called a crash so its important.
When you are going straight the bits of tyre that touch the road make a cylinder and it rolls straight -
But lean a motorcycle tyre and the bit of tyre touching the road has a bigger radius on the outside of the turn than the bit on the inside - it becomes a cone.
Cones don't roll straight, they follow a curve
As somebody already said the extreme weight shift used in racing is largely to keep the bike more upright compared to where the weight is.
Off road bikes are different because you carry the weight on your pegs and on controllable articulated linkages called legs.
Weight shifting is much easier.
The no BS bike isn't hard empirical data.
Its a bit like saying that red lights slow you down because I welded my brake levers so that the red light didn't come and now I can't stop.
Proof that red lights slow you down