Yep, guilty as charged, I am Pat's brother.
Pat keeps telling me the same thing -no tranny required with the Honda motor. Of course Pat is running a souped up GX200, whereas the GC160 does not have any hot rod parts avail at all and I think is around 4.5hp in stock form.
I have run Whizzers, little china motors and even a 9.4HP Morini motor, I find all of them lacking a broad power range that the tranny provides. I only rode Pat's latest 200 model with GX motor up the street and back in the dark, so I don't have any seat of the pants experience.
I appreciate you posting pics of this bike for perspective, the GC with it's flat mount pad is a very good choice for a Simplex conversion, the one in the pic looks like a stock setup.
Where do I find parts? a nice set of rims, hardware to mount the tank, etc. And where is the serial number and how do I convert that info to a build date?
thanks, Rich
ps I will post some pic's soon of the bike.