Did the 18T to 19T Front sprocket conversion. Before and after photos.
As you can see in the second photo, going from 18 to 19 teeth results in a 5.27% reduction in engine revs at a given speed. Looking more closely, we see that there is also a 5.56% increase in speed at any given set of sprocket RPMs.
Well worth doing.
Hope the camera phone pics were clear enough...