Bottom Roller 7136983 for Bobcat E16 E17 E19 E20 Track Roller Track rollers, also known as lower or bottom rollers, are designed to transfer most of the machine's weight and dynamic forces to the ground through the tracks. Forged from deep hardened steel, they are heat treated to increase internal strength to resist bell-mounting and improve rebuildability. Heat-treated housings increase body strength and extend service life. Specifications Parameter Details Name Track roller