Thanks for the replies. I didn't mis-understand SRC. To elaborate, they explained the "negative pre-load" means that fork springs are shorter than inside tube length when fully extended, causing the "subtle clattering" when I ride un-weighted. I'm still curious why some do and some don't. I did notice looking at fork spring specs that a few years after the XR4 came out, spring length was increased about a inch on newer models, but I alwayas figured Honda did so to address the common complaint about soft XR front ends.