Two different issues. Noisy is one thing, but roller failures that trash the engine are exponentially more important. I don't remember hearing about roller failures on relatively stock bikes in the early years of the Twin Cam, but over the past three years or so there seems to have been a big up-tick in reports. Is it the lousy quality of the parts, is it the design that doesn't provide enough oil flow directly to the roller bearings, is it the added stress created by the cam designs, heavy valves, and springs? I have to believe a decent manufacturer with access to well equipped labs can determine the exact cause. My biggest question is, why has H-D been quiet on the subject, and why hasn't the ESP company been raising hell about the major repairs they've had to eat as well?
Maybe someone needs to reinvent the flat tappet and just forget rollers, at least in a Harley.
Jerry