In the context of glass fiber manufacture, the onset of lubrication by a C-18 double-chained cationic surfactant has been investigated at high normal contact pressures. Comparison with adsorption kinetics demonstrates that lubrication is not directly connected to the surfactant surface excess but originates from the transition to a defect-free bilayer that generates limited dissipation. The impact of ionic strength and shear rate has also been studied. (c) 2008 Elsevier Inc. All rights reserved.