Originally Posted by
subgrade
Yes, as long as air resistance and rolling resistance would remain the same, it would indeed happen. Unfortunately, rolling resistance grows with added weight, as there are no absolutely hard wheels and roads in the real world. This is why railroads are the most effective means of transport over land: it takes quite a while for the locomotive to get the whole train rolling, but once it's moving, it is able to pull the thousands of tons quite easily, since the deflection in steel wheels and tracks is minimal.
Increasing tire pressure when running more weight will compensate by restoring tire deflection to the same amount as it was with a lighter weight. But even if the extra weight does still increase rolling resistance, so what? It would be attributed to the weight itself, not some other factor.
It's funny you mentioned the train, because that was my first thought as a test. Place a smooth riding surface between the rails for a bike to ride on while towing a box car. Have locomotive push it up to 15 mph and release. Since (some believe) weight doesn't matter, it should be no problem for the cyclist to keep it rolling on a flat grade even after adding several tons, right?
