In the lines that follow, I have tried to do a mathematical determination about the handling of the bicycle (other terms could be : answer,steerer facility,readiness,capability).
Such characteristic of the bike ,it's always has been little deal, also why it is often not held in consideration from the bike's user.
But this characteristic has its importance why it contributes "to form the character" of the bycicle. In order to make an example practical ,it can be said that , in the races,usual  the "passisti"(that is the cyclist that go fast in the plain )prefers one byke that holds the line well,that is less reactive of steering  regarding the sprinter or the climbers that , to the contrary, wish that the bycicle  fastly favour their desires of trajectory.
This characteristic is determined from the combination of the head angle,of the fork rake, and such I have tried to assume, from the steerer tube height (these quotas are visualized in figure 1 beside).

Usually the problem of the front dimensioning of the bike, comes resolved (in the rewiews or other pubblications),only describing the trail. It's famous as the trail depends mathematically,beyond that on the beam of the wheel ,only from the head angle and the fork rake. Therefore found the ideal trail value for one bike of 28", of any ransom it is, the problem of the dimensioning of the steering and the relative handling, would be resolved.
But then like explaining the fact that ,if on have the fortune to read  a table (reliable) of the sizes of the manufacturer of the frames,it can be seen that to varying  the height of the chassis, it varies also a little the value of the head angle?
Normally,in the road bike, the head angle leaves from a value little more than 72 degree for a small frame size, in order to arrive little beyond the 74 degree for the greater frame size.
With  the text that follows, I have tried to attribute a numerical value to the "Handling", defined terms in the lines over.