Desmodromic valve drive was often justified[citation needed] by claims that springs could not close valves reliably at high speed and that the forces caused by suitably strong springs exceeded what cams could withstand. Since then[when?], valve float was analyzed and found to be caused largely by resonance in valve springs that generated oscillating compression waves among coils, much like a Slinky. High speed photography showed that at specific resonant speeds, valve springs were no longer making contact at one or both ends, leaving the valve floating[9] before crashing into the cam on closure.

For this reason, today as many as three concentric valve springs are sometimes nested inside one other; not for more force (the inner ones having no significant spring constant), but to act as snubbers to reduce oscillations in the outer spring.

An early solution[when?] to oscillating spring mass was the mousetrap or hairpin spring[10] used on Norton Manx[11] engines. These avoided resonance but were ungainly to locate inside cylinder heads. Today, Formula One racing engines use gas springs that have no resonant parts, their working parts having an insignificant mass compared to the force of their compressed gas.

Valve springs that do not resonate are progressive, wound with varying pitch or varying diameter called beehive springs[12] from their shape. The number of active coils in these springs varies during the stroke, the more closely wound coils being on the static end, becoming inactive as the spring compresses or as in the beehive spring, where the small diameter coils at the top are stiffer. Both mechanisms reduce resonance because spring force and its moving mass vary with stroke. This advance in spring design removed valve float, the initial impetus for desmodromic valve drive.