[beatr911]

By my estimation, and this is only me looking at posts at various forums for the last several years, it seems that at about 70mph the very best stock motorcycles get right around 65 mpg. These are usually 250-500cc bikes with some possible 650's and the Honda 700 twin. With gearing changes the 250 Honda and Kawasaki can do a little better.

The only way I see to significantly better this at that speed is through better aerodynamics as Craig Vetter has demonstrated.

Now, if the riding is less than 70mph-ish speeds then the MPG figure goes up in comparison to the 70mph figure on pretty much all bikes. Significantly more so on smaller than about 400cc or so.

To get better than a calculated 70mpg on the 700 twin at rural highway speeds is pretty remarkable actually considering the power, size and (lack of) aerodynamic slickness. And since this is an all-around number including braking and idling I think it's better yet.

From the NC700 forum... "Putting the DCT rear sprocket on the X would drop the teeth from 43 to 39. At 70MPH, this would reduce engine RPM from 3522 to 3194." Don't know how significantly this will affect mileage but it will help the very low first gear you mention. I'd do it if the chain is still in great shape, if not wait like you indicated.