A folding mechanism for a hopper flare, the mechanism comprising a linkage mechanism having a first track provided on a first support, a second track provided on a second support, and a link coupled to both the first and second tracks. The link is capable of riding simultaneously along each of the first and second tracks as the second support pivots about its pivot axis. The first track includes a locking track segment having a bearing surface oriented to resist, by engagement with the link, movement of the second support about the pivot axis in at least one direction.