The velocity of Taylor bubbles in inclined pipes is reduced if a lubricating liquid film between the bubble and the pipe wall is not present. An analytical model predicting the gravity-driven drainage of the lubricating film is presented in this article. The model is then used to establish a criterion for film breakup: if (t) over bar (bubble) = (t) over bar (bubble)/tau < 0.01 the thin film would not break up, where t(bubble) is the bubble's passage time, and tau is the characteristic film drainage time based on the fluid properties, pipe geometry, and critical film thickness. The model is validated experimentally with Taylor bubbles in inclined pipes (5 degrees to 90 degrees, the latter being vertical) with stagnant liquids (ethanol, methanol, and mixtures of deionized water and methanol). (C) 2016 Elsevier Ltd. All rights reserved.