In order for it to roll equally on the frame, you might concider cutting the batting away on one side or both, and folding over the backing and top. Then piecing the batting back in and quilting the side borders at the top of the frame in 2 sections. I have done this and found it to work. When attaching the sides to the top of the frame, the weight of the finished quilt will hold tight and I only needed to attach the side borders to the top leaders and clamp the sides.