I have to butt in with the guys saying they have no vibration on an unbalanced V Twin, I have to say REALLY??? Any engine has points at which resonate frequencies occur and can be felt. If you sit and rev your bike in neutral you will feel the engine isolated, what you will not feel is the transmission engaged and spinning and then the drive - transfer case - and drive belt. This is not that simple and I have never ridden a V Twin that did not vibrate no matter how sophisticated. My Roadie gets a buzz at an indicated 78 miles per hour and at about 81 mph it smooths out. At various other ranges it will buzz in some places more than others depending on the frequency of the other parts. Vibration can be felt in my fuel tank at amlost any speed, but my seat is dead calm as it does not resonate If the buzz is bad, start with the motor mount bolts. Usually when the buzz seems to get worse it can be found in a loose mount at least that is how my Roadie behaves.
Tires are also a vibration point, as mentioned, but they tend to be a variable as they wear. Check your engine mounts, then check your tires. It may be a good idea to check all your board mounting bolts as well. Loose will vibrate and I have read of a few that have vibrated clear off!!!
Good luck

I never had a noticeable vibration until I got rid of the stock pipes.
Now I have vibration in the floorboards at high rpm's.
I noticed it looks like 2 out of the 3 replies of no vibration's have stock exhaust's.