[Angel And The Wolf]

OK, Here's something more easily achieved:

Rebuild the 2 speed sub transmission to change High Range from 1:1.17, to 1:2.

Change the rear wheel to something closer to three qurter size.

You would then have a First Low gear much lower than original for super take offs, and a Fifth High much higher for cruising.

Essentially, a Nine Speed transmission, (First High is still lower than Fifth Low) with a ratio spread from First Low to Fifth High of 6.218, instead of the factory 3.109. Since the trike would be heavier than the CB900C bike, this would help with take off, while giving an almost idle like cruising speed.