Yea, they have a pretty weak top end. Gaining speed in fifth gear is almost impossible. The vibe is from the two cylinder engine and the high RPM´s. Go ahead and visually inspect to make sure you´re motor mounts are tight and the bushings aren´t cracking, if they´re cracked you´ll notice. These are a great little bike but they´re a town bike not a touring bike, if you keep it below 65mph the bikes are decent and great to learn on.