Not too sure about that, had a 250 SuperDream, followed by the 400 SuperDream, both roughly vertical, only horizontal I had was he 500 Susuki GS, also had the Kawasaki 250 LTD from brand new in 1983!
EDIT
My sister wrote off the 250 LTD when working as a motorcycle messenger in London, shortly after she left the Met, fell asleep and went into the back of a double decker!