Tribological devices in cycling: A review.

This review focuses on the measurement of friction forces (Fₜ) and wear in bicycle chain transmissions, analyzing existing devices used to assess transmission efficiency and lubrication regimes relevant to elite cycling. It categorizes forty measurement rigs into five types—full transmission rigs (FTR), single speed rigs (SSR), pendulum rigs (PR), link-focused rigs (LFR), and isolated parameter rigs (IPR)—highlighting their respective advantages, limitations, and ecological validity. The study finds that FTR and SSR most closely replicate real cycling conditions and cover the full range of lubrication regimes encountered in elite time trials, including Boundary, Mixed, and Elasto-Hydrodynamic Lubrication (EHL), with EHL being optimal for low friction and wear. The review emphasizes that rig selection should align with the specific parameters under investigation, and that combining rig types alongside advances in sensor technology can improve measurement accuracy and relevance to real-world cycling performance.