Drafting busses and lorries

TheBrick(Tommy)

It is to do with the center of gravity being high on bike that limits braking power of a bike. The friction which can be archived between the fount tyre and road is greater than or equal to the amount needed to allow rotation about a point (the point in question being the contact point of front wheel to the road surface). DUe to the longer nature of a tandems and cars (also the lower center of gravity) the amount of force required for the car / tandeml to pivot about the contact point it greater than the maximum friction that can be achieved.

Right. Having thought about it some more (not that I suppose anyone cares at this stage), I've come to the somewhat surprising conclusion that the height of your centre of gravity doesn't matter at all. What counts is the diameter of the front wheel and how far back your centre of gravity is. Your maximum deceleration as a fraction of g is (distance c.o.g. behinde axle)/(front wheel diameter). I have diagrams. Yes, I do have better things to do...

no... that's not right either. i was doing statics around the front axle but there's a net acceleration so we need to balance moments around the centre of mass. the right answer is maximum deceleration is
(distance behind axle)/(height above ground). which is more or less what we said in the first place. I'll go and do something else now.