The aim of this paper is to offer a framework for the gradual transition to cycling as a sustainable mode of transport in developing megacities having low or non-existent cycling modal share. By drawing on multi-level perspective, the paper first establishes a socio-technical transition framework incorporating the multi-actor, multi-level and multi-dimensional aspects of the cycling systems. The paper then argues that the transition to cycling is contingent on integrating the multiple dimensions of the cycling socio-technical system. A case study of cycling in Istanbul, a rapidly growing developing megacity in Turkey with a population of nearly 15 million people, is given to illustrate how the proposed framework can be applied. The paper concludes that significant progress towards the introduction of cycling in Istanbul depends on integrating a variety of socio-technical elements including infrastructure, technology, policies and regulations, culture and social meanings. This perspective informs the analysis of the socio-technical transition to cycling for the cities aiming to introduce cycling for the first time. The paper contributes to both sustainable urban mobility and socio-technical transition literature by developing a novel framework for cycling systems.