The vertical force from the tire interaction with the road is superimposed with the whole aero drag stuff we're discussing here.
Not forgotten and an order of magnitude more demanding... but not correlated.
Edit for clarity: the vertical force would create another horizontal force at the front fork mount. Add the bearing friction. They all belong in free body #3. Superimpose.
BTW, if one wants to measure the "power to spin" in the tunnel with the roller motor (or even better, the motors reaction torque), one would of course apply the minimum tire loading possible, just shy of it slipping. My WAG is that the load would be <1% of the typical "road load". So maybe insignificant/in the noise in relation to the aero drag?
Not forgotten and an order of magnitude more demanding... but not correlated.
Edit for clarity: the vertical force would create another horizontal force at the front fork mount. Add the bearing friction. They all belong in free body #3. Superimpose.
BTW, if one wants to measure the "power to spin" in the tunnel with the roller motor (or even better, the motors reaction torque), one would of course apply the minimum tire loading possible, just shy of it slipping. My WAG is that the load would be <1% of the typical "road load". So maybe insignificant/in the noise in relation to the aero drag?