The track is continuous aluminum, no links. I wanted to insure a smooth shot along the rails. The setup would support a long lens just fine. I even think it would support some of the extremely long lenses; I would have to do some testing to be positive. The kart is designed to have a tripod head mounted to it. This gets it up and out of the way for larger cameras. I designed it to be as small as possible to save weight and space. What drives the size is the ability to rotate the wheels to get the rotational shots. I just checked on my solid model and the length between the horizontal wheels is 5.22”. Thanks