At a certain RPM my Shovelhead would vibrate like crazy. Once, on the road between Silver City and Reno, Nevada, a poorly designed spot weld affixing the spot lamp assembly to the forks failed. Bungee cords took care of the problem until I found a welder in Reno who made a Saturday repair.
If I recall correctly, the next year (1985), and all subsequent years, Harley Davidson bolted the spot lamps to the forks.