A poultry processing line with a conveying track and can include at least one carriage movable in the conveying track. Wheels on opposite sides of the carriage are mounted on an axle guided through a shaft or bore of the carriage, and are movable along supports for the respective wheels on opposite sides of the conveying track. The shaft or bore has a convex inner top surface and convex inner bottom surface as seen in the shaft or bore's longitudinal direction.