The original Grove aluminum tail wheel spring was very different and most certainly had a stiffer ride. One of the reasons that spring is no longer produced. The development of the new aluminum spring had that in mind and the attempt was made to have the aluminum spring ride like the steel spring... and it is real close. It is slightly lighter than the steel 3 leaf spring and mounts completely different. Works on the same principal as the main gear using the radius block at the rear mount.