Abstract: A clamping mechanism is provided, the clamping mechanism have two clamps, a tensioning conduit corresponding to each of the clamps, and an actuator for simultaneously tensioning the two clamps by way of the tensioning conduits. Each clamp has a bracing element and a gripping segment, and when the clamps are tensioned along the tensioning conduit, the gripping segment of each clamp is drawn towards the corresponding bracing element. Also provided is a bicycle drive assembly, the assembly has two clamps for fixing to a bicycle, a drive mechanism for driving a bicycle wheel, and two elongate supports extending from the drive mechanism to corresponding clamps. When applied to a bicycle, a wheel of the bicycle passes partially between the elongate supports.