I've got a question that's puzzling me regarding the classic question of why
a cyclist needs to lean inwards towards the centre of the circular motion.
Usually we say that the rider leans inwards so that there is rotational
equilibrium about the CG of the rider right? The frictional force F produces
a moment about the centre of gravity G such that the normal contact force
produces a counterbalance moment. However, while taking the moments about G
solves the issue of rotational equilibrium, if we take the point of rotation
to be anywhere else, (say the point of contact of the rider and the road),
the turning effects no longer appear to be balancing. There'll only be one
moment due to the weight of the bike and biker. Where's the other force
ensuring that the biker does not fall to the ground? Or am I doing something
wrong?