Tracking wheel protection

A pickup assembly of an agricultural harvester, the pickup assembly comprising:

• a pickup assembly frame;
• a tracking wheel;
• and
• a tracking wheel support mechanism attached to the pickup assembly frame, wherein the tracking wheel support mechanism comprises a support arm and a support member, wherein the tracking wheel is rotatably connected to a distal end of the support arm, and wherein a proximal end of the support arm is rotatably connected to the support member about a support member axis which is parallel to the axis of rotation of the tracking wheel, wherein the support arm is restrained against rotation relative to the support member by a frangible member, wherein the frangible member is configured to break when exposed to a predetermined load condition such that the support arm is free to rotate relative to the support member.