Strida is a portable belt-driven folding bicycle with a distinctive A-shaped collapsible frame, designed by British engineer and designer Mark Sanders. The first model, Strida 1, was released in 1987 and the latest, Strida 5.2, in 2009.

A portable bicycle is a bicycle that has been designed to be small and light enough for easy carrying. It is usually dismantled to make a convenient bundle and the frame often has a folding action to facilitate this. The design of a portable bicycle involves a trade-off between ease of carrying and ease of riding.