Until recently, I was not aware of trike technology prior to 1984. I thought the '84 Big Red was the first Big Red, but no. Honda had a chain-drive Big Red in 1982 and 1983, which became the 200M for 1984-1986.
Honda got a good run out of the 200M design. Five years.
On the other hand the 1984 shaft drive Big Red design was only used for one year.
It seems like Honda went to a lot of trouble and engineering expense to come up with the 1984 Big Red design, to only manufacture it for one year. Sure the 85 was a quantum leap forward, but wouldn't it make sense to "upgrade" the 200M with shaft drive and reverse, getting some legs out of the design, rather than throw away all those development dollars?
It's not like the design isn't robust... 26 years later and my well-beat 84 still runs and drives as good as I remember, and nobody's been inside it yet.