After 3 years the butt-joint weld on my 500kg load ARK jockey wheel clamp failed. It was a manufacturing fault. The joint should have been welded on two sides, but was only poorly tacked on one side. It failed under 200kg of load. The warranty is apparently only one year. I am annoyed with the failure, but more annoyed that ARK did not reply when I alerted them to the failure through their web portal.