My original Nomade had one. This RD truly had a mind of its own. Apply a little torque and it may stay in the same cog, but apply more torque (say, to get through an intersection with no time to shift) and it immediately upshifts to the smaller cog. Hated all those unintentional upshifts. Next bike had the SunTour VGT Luxe RD which was worlds better.