I will never understand the lugging or power loss with a 19t. That would mean you are shifting too early. The 19t simply makes your gears much taller. Run the RPMS not the speedo. You don't need 5th gear until over 50-55 and you don't really need 5th gear until about 75-80. The bike has the same power as long as you stay in the same power band. And it works fine off of stop signs and red lights.
