I suspect that more of the fenders that are on bikes that see Jan Heine sourced stuff are metal, not the plastic laminate ones that I was and still use. The metal ones tend to be stiffer and move relative to the tire less during riding. I used a handful of Bicycle Research (possibly still have a set on some shelf) ones, wore through the grazing loop on a few. I also tried an all metal style that had a spring loaded hings early on. But I liked the ability to recurve the BR ones for a better tire contour fit. Andy.