I'm running an 18/42 standard set up at the moment and I often test the lever on the highway to see if there's another gear there.I have done the carb jets/air filter/bellmouth/A.I.blocked/Aftermarket pipes,and the bike runs ok but 19T sprocket is a cheap modification to try so we'll see.If I don't like it it's easy to reverse.
I read or heard somewhere a tooth off or on the back sprocket is worth 2 off or on the front.
