An "overbalanced wheel" tries to keep more weight perpetually on one side by sliding pivoted arms outward as they descend. In an idealised, frictionless world the torque from the falling weights looks unbalanced — but by symmetry the arms rising on the other side need exactly the same torque to lift, so the net work over one revolution is always zero.
E(t) = E0 - ∫ P_friction dt, P_friction = μ N v
No external work in -> ΔE_total ≤ 0 (Second Law)
- Friction coefficient — how much rolling/pivot friction converts kinetic energy into heat each revolution; zero friction is the unreachable "ideal" case that pop-science perpetual-motion claims quietly assume.
- Weight arm offset — how far the sliding weights shift outward; this only changes the torque ripple within a revolution, never the zero net work per cycle.
- Starting spin — the initial angular velocity you give the wheel by hand.
The wheel always visibly slows and stops (even at the friction slider's minimum, real bearings and air drag apply) — a direct demonstration of why "infinite energy" machines violate the second law of thermodynamics: without an external energy input, entropy production (friction) monotonically drains the system's usable energy.