Huh, I'd never thought about a belt dragging from too much surface contact. I use a length of automobile vacume tubing that's a bit wider than 3/16" and rides very high on the hand wheel groove. It also doesn't stretch much, even when left engaged while the machine isn't in use for months. However I didn't think to recommend it because many sewing machines have close fitting belt guards and the thicker tubing might not fit at all. Few things are more frustrating than buying a part to make something work and the part not work.