Originally Posted by
bradtx
I started using my touring bike for distance rides when our drought wrecked havoc with the rural road beds... big cracks where bicycles ride. I had the sensation that it's heavier tires, primarily, and wheel set provided a flywheel effect that made constant speed rides easier. This is over mostly flat land and some gentle rolling terrain.
Brad
Compared to the total inertia of a bicycle and rider, the inertia the wheels is negligible, even factoring that they're rotating weight. Heavier wheels do feel different because you tend to rock the bike so you're feeling the effects of side to side motion and gyroscopic precession, but this has little impact on total forward inertia.
The illusion of differences in weight is important because it affects how the bike feels to you even when it has little actual impact.