[steelerborn]

There are a lot of great tensioning systems you could use. Obviously the easiest set-up would be just adding the kop tensioning system. But interesting systems are also around you could look at cam tension systems for the outside wheels. Making the center wheel direct driven would allow only the outside wheels that would need tensioning. I came up with a lot of crazy systems that would all yield the same result. My favorite one used surgical tubing to move the outside wheels farther out. In the end there is no true answer but a endless supply of them. You have all summer, I would say to experiment a little and find a unique solution that is your design. Keep it up.