I just recently got my bike running well, bought with a bad valve and just replaced it. I was hoping this would go away but it hasn't. When ever the rpms are at 5000-5200  my bike vibrates quite a bit and it sounds like my tach is making a noise. I would understand that the tech would be making noise as the previous owner dropped it right before I bought the bike and the casing is all broken. A new digital gauge is on its way but I was wondering if I should worry about the vibration in the bike. It does it in every gear but only at that 5000 rpms. It doesn't do this vibration when sitting and reving the bike, only when riding down the road. Please any help would be great.

That is a common rpm for vibration on the GS.  Check for missing or out of place rubber bumpers under the tank.

I would say it is quite normal for gs to vibrate anywhere from 5-7K.
My vibrates at around 6-7K but i have learnt to live with that.
I noticed that it is worse when bike is cold.

Cheers
KML