Abstract: A bend detector for use on a pipeline pig assembly comprising a front pig element and a rear pig element pivotally connected to the front pig element by the bend detector; the front pig element having a longitudinally disposed housing with a forward drive cup for driving the assembly by the flow of a fluid through a pipeline system, the rear pig element having a longitudinally disposed housing axially supported in the pipeline, a plurality of odometer wheels radially affixed to the housing of the rear pig element for determining the distance traversed by the assembly through the pipeline system; the bend detector comprising a universal joint having a pair of yoke members pivotally connected to a central member about a pair of mutually perpendicular axes, each of the yoke members having a yoke and a collar, mounting plates for attaching the collars to the front pig element and the rear pig element, respectively, the central member being bored out for receiving a longitudinal hollow sleeve and a central opening