I live for the CABE
LOL, yes kinda hard to explain.Not sure what you're seeing. This is the same roller as has been shown throughout this thread..
My point was that the top roller does not need to have a concave radius that matches the fender radius to remove the dent. It would work the same way if the top roller was flat, or convex. You would just make more passes, and have the advantage of working different areas of the same dent. The concept is the same as working with a body hammer/dolly, you don't start by smashing the middle of the dent first. @SJ_BIKER even shows one top roller in his photo (not installed) that is a flat roller. I guess what I'm asking, "what is the subtle difference between how these different top roller shapes perform"?