Knee speed ≈180: zero torque speed ≈380 Hz
||Bacteria Escherichia coli
||Gabel CV, Berg HC. The speed of the flagellar rotary motor of Escherichia coli varies linearly with protonmotive force. Proc Natl Acad Sci U S A. 2003 Jul 22 100(15):8748-51. p.8749 right column bottom paragraphPubMed ID12857945
||Chen X, Berg HC. Torque-speed relationship of the flagellar rotary motor of Escherichia coli. Biophys J. 2000 Feb78(2):1036-41.PubMed ID10653817
||(Primary source abstract:) "Small latex spheres were attached to flagellar stubs on cells fixed to the surface of a glass slide. The angular speeds of the spheres were monitored in a weak optical trap by back-focal-plane interferometry in solutions containing different concentrations of the viscous agent Ficoll."
||"The torque generated by the motor falls gradually from a
maximum at stall to 90% of that value at a transition region
called the ‘‘knee,’’ and then it falls more rapidly, reaching zero
at the ‘‘zero-torque speed.’’ With a fully energized motor at
24.0°C, the knee and the zero-torque speed occur at ˜180 and
˜380 Hz, respectively, whereas at 16.2°C, the knee and the
zero-torque speed occur at ˜80 and ˜180 Hz , respectively (primary source)."