Materials with helical and double helical structure motifs are prone to display fascinating spring-type behaviour, i.e. a shallow energy surface along the spring-axis in which low-energy vibrations can occur. Recently SnIP has been reported, the first purely inorganic material in which a double helical structure is observed. Quantum chemical calculations reveal a shallow energy landscape with regards to compression and elongation along the helices of the structure. We here propose an inelastic neutron scattering experiment to access the spring-like low-energy vibrations in the materials with the general formula SnXP with X = Cl, Br and I.