its mostly down to tyre compounds which are different for different parts of the tyre so harder comps in the middle and softer towards the wall. aero is a bit more difficult on a bike because of the lean thing, you need the aero on the straight but if it was the same on the corner the bike would fall over, i suspect  as the bike is leant over the aero is also leaning so doesn’t have the same effect. Now for the experts to come along!

Friction between road and tyre resisting centripetal force.  Newton’s equal and opposite reaction.

The angle is determined by how much friction is available.  That depends on the road surface, what the tyre is made of, and how much of it is in contact with the road.  I guess a racing tyre will be made of a soft rubber rounded to squidge more as the bike tilts.  Better grip than a road tyre in exchange for rapid wear.

Obviously limits to how far a bike can tilt, and motor cyclists are extremely vulnerable to oil, water, ice, leaves, gravel, metal covers, or smooth asphalt repairs.  Or expecting a road tyre to allow Guy Martin style cornering on the way back from the pub.

I’ve avoided the maths because I will certainly get it wrong.  Look up centripetal force, or perhaps someone good at sums will explain!

Dave

Could there be anything gained by the fact that the sidewall of the tyre will be trying to “climb up” the road surface as the angle becomes more acute? Or more accurately “across the road surface in the direction of the top of the bike”, dragging it into the bend.

Rob