How heavy are you? Whats your elevation? What type of riding do you do? I ran 15/47 on a road trip once and it was ok as long as there was no head wind. What is nice is that 4th will still run 60+mph if you hit and uphill. If your over 150lbs, high elevation or doing much trail riding i would say no. I have ran 14/47 and 15/50. They are so close you cant tell the difference but either one is a decent all-around gear. If the engine noise bothers you where ear plugs. It sounds better. A 45t would be a good gear if
Your not offroading your tw.