It is really noticeable at idle. The front wheel dances around a little. Lower RPM's while rididng it is noticeable. At highway speed either I don't even notice it or it's not an annoying level. I know on my speedy at highway speeds there is an annoying vibration that causes numbness in my arm if I stay within the rpm range that causes it. The first few times I rode the nightster I was so taken with the way the torque felt during acceleration I don't think I noticed any vibration at any speed other than idle, but now I really pay attention to the details and it is definitely there in lower rpm's.