Anybody remember the old TV show "Then Came Bronson" and specifically a few episodes where the title chartacter would enter his '69 XLCH Sportster in some kind of off-road race???(between getting involved with some guest character's personal family problems, that is)
Yeah, I remember those old episodes, alright! And I also remember wondering how on earth his Sportster "magically" changed into a H-D(actually, as has been mentioned here, an italian-built Aermacchi product) 350 SS Sprint whenever those old Dunlops o' his hit the dirt!!! Strange, huh?!

(oh, and BTW...the Aermacchi 350 Sprints were FOUR-stroke, pushrod horizonal singles)