How can I change the final drive ratio on a shaft drive motorcycle?

Question

The bike is revving too high when I'm on the highway. On a chain drive I'd just swap the rear sprocket, but my current bike is a shaftie. What can I do to raise the final drive ratio a bit?

Answer 1

Freak has it right.

Answer 2

Unless there was some optional gear ratio, you are stuck with what it has. I guess you could go with a taller tire, but that can seriously mess with your handling. When they designed your bike, they put a lot of thought into the RPM the engine would see at various different speeds. The odds are, they made the right choice at the factory.  

Answer 3

You cannot change the final drive ratio. I know of only one motorcycle that had available from the aftermarket a different ratio gear set.  

What you can do is mount a slightly taller rear tire.  I went from a 60 series tire to a 70 series tire on my 1800 Goldwing.  I really liked the results.  Like you, I always felt the engine was "screaming" on the highway.  70 series tire from the Honda VTX works like a charm.  The Wing feels a lot more "relaxed" on the highway.  Gas mileage improves slightly.  

I for one believe in tall geared final drives.  To me the rpms at highway speed should be right in the fat part of the torque/horsepower curve.