6 speed transmission

[ddoug]

I do not think a 6 speed trans is the answer ; I'd rather change ring and pinion to lower the rpm 300-400 at cruise speed; but -Honda probably designed the trans gears around the current ring & pinion because of ring gear diameter. A larger ring gear might not fit in this casting, and a smaller pinion would be weaker.
My guess .

[Cool Hand Luke]

I'd rather stay with 5 but add reverse back instead.

[valkmc]

Owned 1 bike with 6 speed a C-14 and I loved the bike but around down or getting on the expressway I found myself skipping gears. I don't see a need for and extra gear.